WO2021095643A1 - Porous metal body, lighting ornament, lighting device, and method of producing porous metal body - Google Patents

Abstract

This porous metal body 1 has a plurality of holes 3 that are demarcated between titanium-containing fibers 2. The holes 3 include at least seven different types of holes 3 that have different sizes. The seven types of holes 3 are: a hole 3 having a projected area of more than 50 μm2 up to 100 μm2; a hole 3 having a projected area of more than 100 μm2 up to 500 μm2; a hole 3 having a projected area of more than 500 μm2 up to 1000 μm2; a hole 3 having a projected area of more than 1000 μm2 up to 5000 μm2; a hole 3 having a projected area of more than 5000 μm2 up to 10000 μm2; a hole 3 having a projected area of more than 10000 μm2 up to 50000 μm2; and a hole 3 having a projected area of more than 50000 μm2 up to 200000 μm2.

Description

Porous metal body, lighting decoration, lighting equipment, and manufacturing method of porous metal body

The present invention relates to a porous metal body suitable for use in, for example, a decorative tool for a lighting fixture, a lighting decorative tool, a lighting device, and a method for manufacturing the porous metal body.

Some porous metal bodies are formed by depositing titanium-containing fibers or powder made of pure titanium, titanium alloy, etc., heating them, and bonding them to each other by sintering to form a sheet. This type of porous metal body can generally be used as a filter for a high temperature melt, an electrode or base material of a nickel hydrogen battery, a lithium battery or other battery, a part of a fuel cell, or the like. As a technique related to this, for example, there is one described in Patent Document 1.

Japanese Unexamined Patent Publication No. 2016-94663

By the way, the titanium-based porous metal body composed of titanium-containing fibers is expected to be used for purposes other than the existing applications such as the above-mentioned electrodes due to the excellent material properties of titanium.

As an example, it is conceivable to use a titanium-based porous metal body for lighting ornaments arranged around the light source of the lighting equipment, particularly surrounding the light source. In this case, due to the excellent corrosion resistance and light weight of titanium, the luminaire maintains its glossiness for a long period of time and is easy to handle. Further, a decorative tool using a titanium-based porous metal body has an advantage that it can absorb an impact to some extent due to elastic deformation or plastic deformation and is highly safe, unlike a decorative tool made of glass having brittleness.

In addition, lighting ornaments using a titanium-based porous metal body give a visual impression different from those made of other materials due to the light reflection mode peculiar to titanium when receiving light from a light source. Could be given. Patent Document 1 does not pay any attention to such a viewpoint.

An object of the present invention is to provide a porous metal body, a lighting ornament, a lighting device, and a method for manufacturing the porous metal body, which can give a unique visual impression when irradiated with light.

As a result of diligent studies, the inventor determined that the titanium-based porous metal body produced by irregularly arranging the titanium-containing fibers was partitioned between the titanium-containing fibers and had holes of a predetermined size. I devised to have a kind exist. The inventor has found that such a titanium-based porous metal body can give a unique visual impression by reflecting the irradiated light in a manner different from that of other materials. Obtained.

The porous metal body of the present invention has a plurality of pores partitioned between titanium-containing fibers, and the pores include at least seven types of pores having different sizes, and the seven types are included. Has a hole larger than ^{50 μm 2} and having a projected area of ^{100 μm 2} or less, a hole larger than ^{100 μm 2} and having a projected area of ^{500 μm 2} or less, and a hole larger than ^{500 μm 2} and having a projected area of ^{1000 μm 2 or less.} hole, the hole having a large and 5000 .mu.m ² or less of the projected area than 1000 .mu.m ^2, holes having a large and 10000 ² below projected area than 5000 .mu.m ^2, holes having a large and 50000 ² below projected area than 10000 ² and, is that a hole having a large and 200000Myuemu ² or less of the projected area than 50000 ^2.

In the above-mentioned porous metal body, the ratio of the largest number of the pores to the smallest number of the smallest number of the seven types of pores (the largest number). / Minimum number) is preferably 2.0 to 12.0.

Further, in the above-mentioned porous metal body, the total number of the seven types of holes is 100 to 450 in the observation region where the field of view in a plan view is 3000 μm × 2210 μm, and the total number of the seven types of holes is 100 to 450, which occupies the observation region. The ratio of the total projected area of the seven types of holes is preferably 25% to 45%.

The above-mentioned porous metal body can have an oxide film layer covering the titanium-containing fiber. Various colors can be expressed by the oxide film layer.

The above-mentioned porous metal body is an image of the porous metal body taken in a state where the porous metal body is irradiated with light, and the brightness V of each pixel is set to V = based on an RGB color model. Pixels with a brightness V greater than 50 and in the range of 75 or less, pixels with a brightness V greater than 75 and in the range of 100 or less, calculated by the formula 0.299 × R + 0.587 × G + 0.114 × B. Pixels with a brightness V greater than 100 and in the range 125 or less, pixels with a brightness V greater than 125 and in the range 150 or less, pixels with a brightness V greater than 150 and in the range 175 or less, and pixels with a brightness V greater than 175. Pixels large and in the range of 200 or less, pixels with a brightness V greater than 200 and in the range of 225 or less, pixels with a brightness V greater than 225 and in the range of 250 or less, and pixels with a brightness V greater than 250 and 275 or less. There are all pixels in the range of, and the difference between the maximum percentage of the number of pixels in each range and the minimum percentage of the number of pixels is the smallest. , 8% -40% is preferable.

In this case, the maximum ratio is preferably 40% or less.

The above-mentioned porous metal body can be in the form of a sheet having a thickness of 0.1 mm to 0.4 mm.

The above-mentioned porous metal body can be used for lighting ornaments, for example.

The lighting ornament of the present invention includes any of the above-mentioned porous metal bodies.

The lighting device of the present invention includes the above-mentioned lighting ornament and a light source.

The method for producing a porous metal body of the present invention produces a plurality of titanium-containing fibers bonded to each other in different directions and a porous metal body having a plurality of pores partitioned between the titanium-containing fibers. In this method, a fiber deposition step of depositing a plurality of titanium-containing fibers and a titanium-containing fiber deposited in the fiber deposition step are bonded to each other by sintering to obtain a sintered body of the titanium-containing fibers. Check the knotting process, the thickness of the sintered body and the projected area of the holes, and select a ^{sintered body whose thickness is within ± 30% of the target thickness and whose projected area is larger than 200,000 μm 2 and} has no holes. , Including an inspection step of forming a porous metal body.

The above-mentioned method for producing a porous metal body may further include a thickness adjusting step of pressing or rolling the sintered body after the sintering step.

Further, the above-mentioned method for producing a porous metal body may further include an oxidation step of performing an oxidation treatment on the titanium-containing fibers of the sintered body after the sintering step.

In the method for producing a porous metal body described above, it is preferable to use the titanium-containing fiber having a polygonal cross-sectional shape in the fiber deposition step.

In the method for producing a porous metal body described above, it is preferable to use titanium-containing fibers having a length of 1 to 9 mm in the fiber deposition step.

According to the present invention, the porous metal body can give a unique visual impression when irradiated with light.

It is a perspective view which shows the porous metal body of one Embodiment of this invention. It is a schematic plan view which shows the part of the porous metal body of FIG. 1 enlarged. The method of measuring the projected area of the pores of the porous metal body is shown. FIG. 3 (a) is an SEM image of the porous metal body, and FIG. 3 (b) is an image in which the brightness of the SEM image is maximized. 3 (c) is an image in which the histogram extraction of the luminance area extraction is further used for the image, and FIG. 3 (d) is an image in which the projected area of the hole is calculated. It is a perspective view which shows the lighting ornament including the porous metal body of FIG. 5 (a) is a schematic view showing a method of acquiring an image used for calculating the brightness of a porous metal body, and FIG. 5 (b) is an enlarged cross-sectional view taken along line bb of FIG. 5 (a). It is an SEM photograph of the porous metal body of Example 1. It is a graph which shows the number distribution of the pores having the projected area in a predetermined range about the porous metal body of Example 1. FIG. 8 (a) is an SEM image in which the brightness of the Japanese paper of Comparative Example 1 is maximized, FIG. 8 (b) is an SEM image in which the brightness of the Japanese paper of Comparative Example 2 is maximized, and FIG. 8 (c) is a comparative example. The SEM image in which the brightness of the stainless mesh of No. 3 is maximized, and FIG. 8D is an SEM image in which the brightness of the stainless mesh of Comparative Example 4 is maximized. 9 (a) is a photograph showing the porous metal body of Example 1 at the time of light irradiation, FIG. 9 (b) is a photograph showing the porous metal body of Example 2 at the time of light irradiation, and FIG. 9 (c) is a photograph showing the porous metal body of Example 2. A photograph showing the porous metal body of Example 3 at the time of light irradiation, FIG. 9 (d) is a photograph showing the porous metal body of Example 4 at the time of light irradiation, and FIG. 9 (e) shows a target area for image analysis. It is a figure which shows. FIG. 10 (a) is a photograph showing the Japanese paper of Comparative Example 1 at the time of light irradiation, FIG. 10 (b) is a photograph showing the Japanese paper of Comparative Example 2 at the time of light irradiation, and FIG. 10 (c) is a comparative example at the time of light irradiation. 3 is a photograph showing the stainless mesh, FIG. 10 (d) is a photograph showing the stainless mesh of Comparative Example 4 at the time of light irradiation, and FIG. 10 (e) is a photograph showing the cellophane of Comparative Example 5 at the time of light irradiation, FIG. 10 ( f) is a photograph showing the cellophane of Comparative Example 6 at the time of light irradiation. FIG. 11A is a graph showing the brightness distribution in the porous metal body of Example 1 during light irradiation, and FIG. 11B is a brightness distribution in the porous metal body of Example 2 during light irradiation. 11 (c) is a graph showing the brightness distribution in the porous metal body of Example 3 at the time of light irradiation, and FIG. 11 (d) is a graph showing the luminance distribution in the porous metal body of Example 3 at the time of light irradiation. It is a graph which shows the distribution of the brightness of. FIG. 12 (a) is a graph showing the luminance distribution of Japanese paper in Comparative Example 1 during light irradiation, and FIG. 12 (b) is a graph showing the luminance distribution of Japanese paper in Comparative Example 2 during light irradiation. (C) is a graph showing the brightness distribution on the stainless mesh of Comparative Example 3 during light irradiation, and FIG. 12 (d) is a graph showing the brightness distribution on the stainless mesh of Comparative Example 4 during light irradiation, FIG. 12 (E) is a graph showing the brightness distribution of the cellophane of Comparative Example 5 during light irradiation, and FIG. 12 (f) is a graph showing the brightness distribution of the cellophane of Comparative Example 6 during light irradiation.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 shows a porous metal body 1 according to an embodiment of the present invention. The porous metal body 1 has, for example, a sheet-like shape, a flat plate, or a plate-like shape having a predetermined thickness. The porous metal body 1 has a plurality of holes 3 as illustrated in the partially enlarged plan view in FIG. 2, but has a sheet-like shape as a whole based on the outer edge of the porous metal body 1. Can be understood. More specifically, the porous metal body 1 includes a plurality of titanium-containing fibers 2 bonded to each other in different directions, and a plurality of holes 3 partitioned between the titanium-containing fibers 2 and penetrating in the thickness direction of the sheet. It has a structure like a so-called three-dimensional network structure. The above-mentioned "different orientation" means that the length directions of the titanium-containing fibers 2 are oriented in different directions in a plan view. The porous metal body 1 has a thickness, and it is actually possible to conceive the direction of the titanium-containing fiber 2 not only in the direction on the plane but also in the thickness direction, but in the present embodiment, the directions are different in the plan view. It suffices if it can be confirmed that the titanium-containing fibers 2 of the above are bonded to each other by sintering or the like. Further, when the porous metal body 1 is formed in a tubular shape as shown in FIG. 4, it can be expanded into a sheet shape as shown in FIG. 1 to confirm the direction of the titanium-containing fiber 2 and the projected area of the hole.

Here, as the material of the titanium-containing fiber 2, various materials can be used as long as it contains titanium. Specifically, JIS H 460: 2012 pure titanium 1 to 4 types, and the titanium alloy is an alloy with metals such as Fe, Sn, Cr, Al, V, Mn, Zr, and Mo. , Ti-6-4 (Ti-6Al-4V), Ti-5Al-2.5Sn, Ti-8-1-1 (Ti-8Al-1Mo-1V), Ti-6-2-4-2 (Ti) -6Al-2Sn-4Zr-2Mo-0.1Si), Ti-6-6-2 (Ti-6Al-6V-2Sn-0.7Fe-0.7Cu), Ti-6-2-4-6 (Ti) -6Al-2Sn-4Zr-6Mo), SP700 (Ti-4.5Al-3V-2Fe-2Mo), Ti-17 (Ti-5Al-2Sn-2Zr-4Mo-4Cr), β-CEZ (Ti-5Al- 2Sn-4Zr-4Mo-2Cr-1Fe), TIMETAL555, Ti-553 (Ti-5Al-5Mo-5V-3Cr-0.5Fe), TIMETAL21S (Ti-15Mo-2.7Nb-3Al-0.2Si), TIMETAL LCB (Ti-4.5Fe-6.8Mo-1.5Al), 10-2-3 (Ti-10V-2Fe-3Al), Beta C (Ti-3Al-8V-6Cr-4Mo-4Cr), Ti- 8823 (Ti-8Mo-8V-2Fe-3Al), 15-3 (Ti-15V-3Cr-3Al-3Sn), BetaIII (Ti-11.5Mo-6Zr-4.5Sn), Ti-13V-11Cr-3Al Titanium alloys such as The titanium-containing fiber 2 may be made of JIS H 460: 2012 pure titanium 1 to 4 types, or pure titanium 1 to 2 types.

As can be seen from the illustration in FIG. 2, the illustrated porous metal body 1 is partitioned by the titanium-containing fibers 2 because the plurality of titanium-containing fibers 2 are irregularly arranged in different directions. The plurality of holes 3 to be formed are non-uniform and have various sizes and shapes. In many cases, the titanium-containing fibers 2 in the porous metal body 1 are randomly oriented. Based on this, the porous metal body 1 includes holes 3 having various shapes and various sizes in a plan view, for example. That is, in many cases, the shape and size of the pores 3 formed in the porous metal body 1 in a plan view are random.

And here, it is assumed that the hole 3 includes at least seven types of holes 3 having different sizes. Specifically, seven kinds of the hole 3, the hole portion 3,500Myuemu ² having a large and 500 [mu] m ² or less of the projected area than the hole 3,100Myuemu ² having a large and 100 [mu] m ² or less of the projected area than 50 [mu] m ² hole 3,10000μm having larger and larger and 10000 ² below projected area than the hole 3,5000Myuemu ² having a large and 5000 .mu.m ² or less of the projected area than the hole 3,1000Myuemu ² having a projected area of 1000 .mu.m ² below hole 3 having a larger and 50000 ² below projected area than ^2, and means a hole 3 having a larger and 200000Myuemu ² or less of the projected area than 50000 ^2. The porous metal body 1 typically has no pores ^{having a projected area larger than 200,000 μm 2.}

By including at least seven types of pores 3 having such a relatively wide range, when the porous metal body 1 is irradiated with light, the light divides the seven types of pores 3. The titanium-containing fiber 2 is reflected in a unique manner. If the titanium-containing fiber 2 has an irregular arrangement, the tendency becomes remarkable. As a result, a unique visual impression can be given when irradiated with light.

The projected area of the hole 3 means the area of the projected surface corresponding to the hole 3 when a shadow is projected on a plane along the thickness direction of the sheet-shaped porous metal body 1. , Ask as follows. First, the porous metal body 1 is photographed with a scanning electron microscope (SEM), and an SEM image (brightness of about 70) having a magnification of 100 times and a field of view of 3000 μm × 2210 μm (area: 6630000 μm ^{2) as shown in FIG. 3 (a).} To get. Next, a conversion process for increasing the brightness of the SEM image to 255 (maximum) is performed to obtain an image as shown in FIG. 3 (b). After that, the part having a brightness of 120 or less is made white, and the part having a brightness greater than 120 is made black. Processing is performed using the histogram extraction function of the luminance area extraction in which the luminance range is 0 to 120. As a result, the titanium-containing fibers are represented in black and the pores are represented in white. Since the background is also included in the SEM image, it is preferable to remove noise derived from the background. For example, a black mottled pattern may remain in the hole, and in such a case, a group of minute black pixels (for example, one having a size of 1000 pixels or less) that is clearly not titanium-containing fiber 2 is white pixels. Convert to to remove noise. Furthermore, a group of white pixels (for example, one having a size of 500 pixels or less) may unintentionally enter the region apparently considered to be the titanium-containing fiber 2. In such a case, the white pixel is converted into a black pixel to remove noise. By the above processing, an image as shown in FIG. 3C is obtained. The area of each portion (white portion in FIG. 3C) corresponding to the hole 3 is calculated by image analysis as shown in FIG. 3D. Here, each of the hole portions 3 whose part is located at the periphery (most end) of the image is also regarded as one hole portion 3.
When determining the total number of holes existing in the field of view of the porous metal body 1 of 3000 μm × 2210 μm and the ratio of the total projected area of the holes, such image analysis is performed by performing such image analysis. The field of view is performed, and the average value of the values calculated thereby is defined as the total number of holes or the ratio of the total projected area of the holes.

The porous metal body 1 has a projected area of ^{more than 50 μm 2} and 100 μm ² or less, a range of ^{more than 100 μm 2} and 500 μm ² or less, a range of ^{more than 500 μm 2} and 1000 μm ² or less, and a pore area of 1000 μm ^{2 or} less. large and 5000 .mu.m ² following ranges, large and 10000 ² the range from 5000 .mu.m ^2, and greater than 10000 ² 50000 ² below, and, seven contained the seven each range is large and 200000Myuemu ² the range from 50000 ² Any type of hole 3 may be present. That is, the presence of at least one hole 3 included in each of the seven ranges described above with respect to the projected area can produce the effect of giving the above-mentioned unique visual impression. The "type" of the seven types of holes 3 referred to here is used as a term for classifying common items only with respect to the size of the projected area, and the shape and the like are not limited.

From the projected area of each hole 3 calculated as described above, the number of holes 3 that fall into each of the seven ranges described above can be obtained. In this case, the ratio of the maximum number of holes 3 to the minimum number of the smallest number of holes 3 among the seven types of holes 3 (maximum number / minimum number) is , 2.0 to 12.0 is preferable. For example, greater than 500 [mu] m ² and is the most number of 1000 .mu.m ² below hole 3, greater than 50000 ² and when the number of 200000Myuemu ² below hole 3 is smallest, greater than 500 [mu] m ² and 1000 .mu.m ² following hole It is preferable that the number of 3 is the maximum number, the number ^{of holes 3 larger than 50,000 μm 2} and 200,000 μm ² or less is the minimum number, and the ratio of the maximum number to the minimum number is 2.0 to 12.0. When the ratio of the maximum number to the minimum number is 2.0 to 12.0, it is different from the case where the light is applied to a material made of other metal materials, cellophane, etc., as compared with the case where the ratio is out of the range. It can give a unique visual impression more clearly. From this point of view, the ratio of the maximum number to the minimum number is even more preferably 4.0 to 10.0. The ratio of the maximum number to the minimum number is even more preferably 5.0 to 8.0. If a graph is created in which the horizontal axis includes the above-mentioned seven projected areas and the vertical axis is the number of holes 3, the distribution of the projected areas of the holes 3 can be grasped.

Further, when an observation region having a field of view of 3000 μm × 2210 μm, that is, an area of 6630000 μm ² is set in a plan view of the porous metal body 1, the number of each of the above-mentioned seven types of holes 3 existing in the observation region. The total number of holes 3 which is the total number of holes 3 is preferably 100 to 450, and more preferably 200 to 400. Further, the ratio of the total projected area of the hole 3 which is the total of the projected areas of each of the seven types of holes 3 in the observation area, that is, the ratio of the total projected area to the area of the observation area is preferable. It is 25% to 45%, more preferably 30% to 40%. Thereby, a suitable visual impression can be achieved. By reducing the number of holes 3 to 450 or less, the size of each hole 3 is secured to some extent, so that a bright and vague impression like Japanese paper is suppressed, and a characteristic light with strong and weak is exhibited. It becomes easy to be done. By setting the number of the holes 3 to 100 or more, it is possible to suppress the monotonous light like a stainless mesh. Here, even if there is a hole 3 other than the seven types of holes 3, that is, a hole 3 having a projected area of 50 μm ² or less, the total number and the total projected area are calculated for the hole 3. Not included in.
The total number of the holes 3 is even more preferably 250 to 350.

By the way, it is preferable that the porous metal body 1 has an oxide film layer covering the titanium-containing fiber 2 because the titanium-containing fiber 2 is subjected to an oxidation step described later. _{The oxide film layer may contain titanium dioxide (TiO 2} ) and other titanium oxides such as rutile type and anatase type as a result of the oxidation of mainly titanium of the titanium-containing fiber 2. In addition, the oxide film layer may contain at least one selected from electrolyte-derived anions and water.
In this case, the titanium-containing fiber 2 and the porous metal body 1 having the titanium-containing fiber 2 exhibit various colors such as cherry blossom, blue, green, orange, and yellow due to the oxide film layer covering the titanium-containing fiber 2 in a light environment. be able to.

The thickness of the oxide film layer is typically 0.001 μm to 1.0 μm. By controlling the thickness of the oxide film layer, a desired color can be achieved. The thickness of the oxide film layer is measured by STEM-EDX or the like on the cross section of the titanium-containing fiber 2 produced by the focused ion beam (FIB) processing.
The thickness of the oxide film layer may be 0.01 μm to 1.0 μm. Further, it may be 0.01 μm to 0.30 μm.

As an example, the porous metal body 1 as described above can be used for the lighting ornament 11 as shown in FIG. The lighting decoration tool 11 is a porous metal body 1 in which a sheet-shaped object shown in FIG. 1 is wound so as to be substantially cylindrical so that the sheet ends are brought into contact with or close to each other, and the porous metal body 1 thereof. It is arranged on the outer peripheral side so as to surround the porous metal body 1 and includes a cylindrical container 21 made of a transparent or translucent material such as glass or plastic. In the lighting accessory 11 of FIG. 4, a light source 31 such as a light bulb that emits light by connection to a power source or a battery or other means is arranged below the bottom of the cylindrical container 21 as illustrated in FIG.

Here, the cylindrical container 21 has a bottom portion 21a that supports the inner lighting ornament 11 at one end in the axial direction (lower end in FIG. 4) and an other end (upper end in FIG. 4). The portion) is provided with an inclined surface-shaped opening end surface 21b along a plane inclined in the axial direction. However, the cylindrical container 21 is not limited to this, and may have various shapes, and the cylindrical container 21 is not always necessary. Depending on the lighting ornament, the porous metal body 1 may be rolled into a cylinder in a mode other than the above-mentioned mode.

In the lighting ornament 11 shown in FIG. 4, in the porous metal body 1, the light from the light source 31 on the lower side thereof is the surface of the titanium-containing fiber 2 that partitions at least seven types of holes 3 having different sizes as described above. By being reflected by, it gives off a brilliance that gives a unique impression that light spreads in the porous metal body 1. The lighting accessory 11 and the lighting device provided with the lighting accessory 11 and the light source 31 can be suitably used particularly under a light amount (darkness) in the evening to the night.

As shown in FIG. 5A, the light source 31 arranged on the lower side of the cylindrical container 21 of the lighting decoration 11 irradiates the porous metal body 1 of the lighting decoration 11 with light, and the light is porous. By taking an image of the lighting decoration tool 11 including the quality metal body 1, the brightness of the porous metal body 1 due to the reflection of light from the light source 31 can be evaluated. Here, as shown in FIG. 5B, the light source 31 is a transparent cylindrical outer cylinder 32 having an outer diameter similar to that of the cylindrical container 21 and arranged below the cylindrical container 21. It is located in the center of the inside. The cylindrical container 21 is a product name manufactured by Sumitomo Chemical Co., Ltd .: Sumipex E (material: PMMA, thickness: 2 mm, total light transmittance: 92.6 (JIS K7361-1: 1997), refractive index: 1.49 ( JIS K7105: 1981)) and the like can be used.

Then, the camera 33 captures and acquires an image of the lighting ornament 11 including the porous metal body 1. With respect to the image obtained thereby, the brightness V of each pixel is calculated by the formula of V = 0.299 × R + 0.587 × G + 0.114 × B based on the RGB color model. In the image, the center of the porous metal body 1 wound around the cylinder in the width direction (horizontal direction in FIG. 5) is the center of the image, the total number of pixels is 718953, the number of pixels on the vertical axis is 1101, and the number of pixels on the horizontal axis is 1101. The area of 653 is the target area.

In this case, a pixel having a brightness V greater than 50 and in the range of 75 or less, a pixel having a brightness V greater than 75 and in the range of 100 or less, a pixel having a brightness V greater than 100 and in the range of 125 or less, and a brightness V. Is greater than 125 and is in the range of 150 or less, the brightness V is greater than 150 and is in the range of 175 or less, the brightness V is greater than 175 and is in the range of 200 or less, the brightness V is greater than 200 and It is preferable that there are pixels in the range of 225 or less, pixels having a luminance V greater than 225 and in the range of 250 or less, and pixels having a luminance V greater than 250 and in the range of 275 or less. Further, among the ratio of the number of pixels in each of the above ranges (percentage of the number of pixels in each range to the total number of pixels), the maximum ratio with the largest ratio and the minimum ratio with the smallest ratio. The difference from the ratio is preferably 8% to 40%. For example, the ratio of the number of pixels in the range of brightness V greater than 225 and 250 or less is the largest and its value is 24%, and the ratio of the number of pixels in the range of brightness V greater than 50 and 75 or less is the smallest. When the value is 1%, the difference between the maximum ratio and the minimum ratio is 23%. Here, more preferably, the difference between the maximum ratio and the minimum ratio is 10% to 35%, and further 10% to 30%. This makes it easier to achieve a unique aesthetic after anodizing. The brightness distribution can be represented by a graph in which the horizontal axis is each range of the above-mentioned brightness V and the vertical axis is the ratio of the number of pixels.
The difference between the maximum ratio and the minimum ratio may be 20% to 30%.

Further, in this case, the maximum ratio, which is the ratio of the pixels having the largest ratio, is further preferably 40% or less, more preferably 35% or less, still more preferably 30% or less. is there. When the maximum ratio is so small, it is possible to achieve a good visual impression with few locally bright areas.

When the porous metal body 1 is in the form of a sheet, the thickness of the sheet-shaped porous metal body 1 is preferably 0.1 mm to 0.4 mm, more preferably 0.1 mm to 0.3 mm, still more preferably. Is preferably 0.1 mm to 0.2 mm. By setting the thickness within such a range, a unique visual impression is better exhibited when light is transmitted. The thickness of the porous metal body 1 is measured at nine points on the surface of the porous metal body 1 with a contact probe and used as an average value thereof. For example, in the case of a sheet-like porous metal body 1 having a rectangular planar shape, nine points separated from the outer edge at equal intervals in the length direction and the width direction are set as measurement points.
The thickness of the sheet-shaped porous metal body 1 may be 0.1 mm to 0.6 mm.

The porosity of the porous metal body 1 can be, for example, 80% to 95%. In order to obtain porosity, the volume is calculated from the thickness, length and width of the porous metal body 1 obtained as described above. Next, the measured density is obtained from the volume and the weight measured by a balance, etc., and this measured density is ^{divided by the true density (4.51 g / cm 3 in} the case of pure titanium), and this is expressed as a percentage relative density. Calculate (%). Porosity is calculated from the formula: porosity (%) = (1-relative density) × 100.

The porous metal body 1 as described above can be produced, for example, as follows.
First, a fiber deposition step of depositing a plurality of titanium-containing fibers 2 on, for example, a flat surface is performed. The titanium-containing fiber 2 used here can be obtained, for example, by performing a coil cutting method, a chatter vibration cutting method, or the like on a titanium-containing mass or plate. Therefore, the titanium-containing fiber 2 may include one having a broken shape and one having a curved shape. When measuring the length of the titanium-containing fiber 2, it is sufficient to pick up the linear titanium-containing fiber 2 and determine its size as described later. The obtained titanium-containing fiber 2 often has a cross-sectional shape in a direction orthogonal to the longitudinal direction thereof, which is a polygonal shape defined by three or more straight lines, and has such a polygonal cross-sectional shape. When the titanium-containing fiber 2 is used, the produced porous metal body 1 gives a more unique visual impression when irradiated with light, which is preferable.

The length of the titanium-containing fiber 2 may be 1 mm to 9 mm, preferably 1 mm to 6 mm. This is to give a unique visual impression to the porous metal body 1 to be manufactured. If the length of the titanium-containing fiber 2 is too short, the pores 3 formed in the porous metal body 1 may become too small or too large. Further, if the length of the titanium-containing fiber 2 is too long, the orientation of the titanium-containing fiber 2 tends to be aligned in the porous metal body 1. The diameter of the titanium-containing fiber 2 can be 20 μm to 90 μm. By using the titanium-containing fiber 2 having a diameter in this range, a good porous metal body 1 can be produced. The length and diameter of the titanium-containing fiber 2 are measured using an optical microscope. In an optical microscope, the length of the thickest portion on the short side of the titanium-containing fiber 2 in the field of view is defined as the diameter, and the length of the longest portion on the long side is defined as the length.
A more specific measurement method is to use a Keyence optical microscope VHX-6000 to randomly collect data of 50 samples at a magnification of 100 times and use the average value. At the time of measurement, bent samples are excluded.

In the fiber deposition step, by using the titanium-containing fiber 2 instead of the titanium-containing powder, it becomes easy to obtain the porous metal body 1 having at least seven kinds of pores 3 having different sizes as described above. When the titanium-containing powder is used, a porous metal body having more uniform mechanical strength and voids is produced, and such a porous metal body has a predetermined hole and the above-mentioned result. It is difficult to obtain a unique visual impression.
The "fiber" of the titanium-containing fiber 2 referred to here means a fiber having a length / diameter of 5 or more and 350 or less.

The titanium-containing fiber 2 can be deposited, for example, by manually shaking off the titanium-containing fiber 2 from the upper side of the plane. According to this, the titanium-containing fibers 2 are deposited on a flat surface in different directions irregularly, which is preferable. Alternatively, the titanium-containing fiber 2 may be deposited using an apparatus as described in JP-A-2007-262571.

Next, a sintering step is performed in which the titanium-containing fibers 2 deposited in the fiber deposition step are bonded to each other by sintering to obtain a sintered body of the titanium-containing fibers 2. Here, the deposited titanium-containing fiber 2 is heated to preferably 900 ° C. to 1200 ° C., more preferably 900 ° C. to 1100 ° C. Further, preferably, heating is performed in a vacuum atmosphere of ^{10 -4} Pa to ^10-2 Pa, and further preferably 10 ^-3 Pa to ^{10-2 Pa.} Alternatively, a He or Ar gas atmosphere may be used. In addition, spacers may be arranged and sintered so as to have a predetermined thickness.

After that, the thickness adjustment process can be performed as needed. In the thickness adjusting step, the above-mentioned sintered body is pressed or rolled to reduce the thickness of the sintered body, for example, to be within the range of the thickness of the porous metal body 1 described above. In the thickness adjusting step, when the thickness of the sintered body is non-uniform, the thickness can be made uniform. This may improve the yield.

After the sintering step, or when the thickness adjusting step is performed, after the thickness adjusting step, in the inspection step, the thickness and the projected area of the hole 3 of the sintered body are measured by the method described above. Then, a sintered body having a thickness within ± 30% of the target thickness and ^{having no pores having a projected area larger than 200,000 μm 2} is defined as a porous metal body. If there is a hole having a projected area ^{larger than 200,000 μm 2} , the amount of light leaking from the specific part is large, and the desired visual impression cannot be obtained. Further, if the thickness exceeds ± 30% of the target thickness, excessive bias occurs in the passage of light, and a desired visual impression cannot be obtained. The target thickness can be, for example, in the range of 0.1 mm to 0.4 mm, more preferably 0.1 mm to 0.3 mm, and even more preferably 0.1 mm to 0.2 mm.

In some cases, after the sintering step, an oxidation step of oxidizing the titanium-containing fibers of the sintered body may be performed. The oxidation step may be performed after the sintering step, after the sintering step and before the thickness adjustment step, after the thickness adjustment step and before the inspection step, or after the inspection step. Good.

In the oxidation step, the titanium-containing fiber can be subjected to an oxidation treatment by anodizing or the like using a predetermined electrolytic bath by a known method. As a result, the thickness of the oxide film layer covering the titanium-containing fiber is adjusted, and the titanium-containing fiber is colored in a predetermined color by the oxide film layer. Here, by appropriately setting the electrolytic conditions so as to control the thickness of the oxide film layer, the titanium-containing fibers covered with the oxide film layer exhibit a desired color.

Known conditions for the oxidation treatment can be appropriately adopted and are not particularly limited, but for example, the oxidation step can be carried out by the following oxidation treatment. First, the porous metal body, which is a sintered body that has undergone the sintering step, is subjected to a degreasing treatment and a pickling treatment. The degreasing treatment is performed to improve the wettability at the time of forming the oxide film and to suppress color unevenness. The degreasing treatment can be performed using ethanol, acetone, or an alkaline solution. Pickling is performed to remove smut, which evens out the surface roughness. The pickling treatment may be performed once or a plurality of times. For example, the pickling treatment can be performed using a hydrofluoric acid-nitric acid mixed solution or a hydrofluoric acid-hydrogen peroxide aqueous solution. Since a more uniform surface can be obtained by chelating and stabilizing titanium ions, it is preferable to perform a pickling treatment using a hydrofluoric acid-hydrogen peroxide aqueous solution.
After that, an oxidation treatment can be carried out. An example of the oxidation treatment procedure is as follows. An aqueous solution of copper (II) sulfate is injected into a non-conductive electrolytic cell (plastic, glass, vinyl chloride, etc.). Insert a stainless steel or titanium cathode inside the non-conductive electrolytic cell. A porous metal body is sandwiched between clips to serve as an anode, and the mixture is immersed in an aqueous solution of copper (II) sulfate. Energize by adjusting the voltage to develop the target interference color. It is possible to change the color development by changing the voltage. After the oxide film layer is formed, the energization is stopped, the porous metal body is taken out from the non-conductive electrolytic cell, and washed with water. After washing with water, the surface may be appropriately coated for the purpose of preventing discoloration.

Next, the porous metal body of the present invention was prototyped and its effect was confirmed, which will be described below. However, the description here is for the purpose of mere illustration, and is not intended to be limited thereto.

(Example)
After depositing 2.11 g of titanium-containing fiber having a polygonal cross-sectional shape, length: 3 mm, diameter: 30 μm, and equivalent to JIS standard 2 on a flat surface, this is placed at 1000 ° C., 10 ^-3 Pa ~. A sheet-like sintered body was obtained by pressurizing and sintering under vacuum conditions in the range of ^{10-2 Pa.} Then, the sheet-shaped sintered body was roll-rolled under the condition of aiming at a final thickness of 0.20 mmt. When a plurality of the sintered bodies were prepared and the sintered bodies were inspected, 20% were judged to be unacceptable.
In Example 1, the sintered body which did not perform the oxidation step and had no problem in the above-mentioned inspection step was used as a porous metal body. The thickness of this porous metal body was 0.22 mm, the length was 250 mm, the width was 100 mm, and the porosity (porosity) was 89.5%. For reference, FIG. 6 shows a partial SEM photograph of the porous metal body of Example 1.

With respect to the porous metal body of Example 1, the projected area of the pores was calculated as described above, and the number of pores having the projected area within a predetermined range was determined. As the SEM, VHX-D510 manufactured by KEYENCE Co., Ltd. was used, the brightness was maximized at 255 steps and 255, the target field of view was 3000 μm × 2210 μm, and 5 fields of view were observed.
The average value of the five visual field observation results is shown in FIG. In the graph shown in FIG. 7, the horizontal axis is a predetermined range of the projected area of the hole (a range ^{larger than 0 μm 2} and 10 μm ² or less, a range ^{larger than 10 μm 2} and 50 μm ² or less, a range ^{larger than 50 μm 2} and 100 μm ² or less. range, large and 500 [mu] m ² or less in the range from 100 [mu] m ^2, larger and 1000 .mu.m ² the range from 500 [mu] m ^2, larger and 5000 .mu.m ² the range from 1000 .mu.m ^2, large and 10000 ² the range from 5000 .mu.m ^2, from 10000 ² The range is large and 50,000 μm ² or less, and the range is larger than ^{50,000 μm 2 and 200,000 μm 2} or less), and the vertical axis is the number of holes that fall into each of these ranges.
From FIG. 7, it can be seen that the porous metal body of Example 1 has all seven types of predetermined pores. The maximum number / minimum number of pores in the porous metal body was 6.4. The ratio of the total projected area of the seven types of holes to the observation area was 36%. The total number of the seven types of holes was 245. The breakdown is large and 10 [mu] m ² or less in the range from 0 .mu.m ^2: 0, greater than 10 [mu] m ² and 50 [mu] m ² or less in the range: 0, greater than 50 [mu] m ² and 100 [mu] m ² or less in the range: 9, greater than 100 [mu] m ² and 500 [mu] m ² or less in the range: 56, greater than 500 [mu] m ² and 1000 .mu.m ² following ranges: 22, greater than 1000 .mu.m ² and 5000 .mu.m ² following ranges: 58 pieces, greater than 5000 .mu.m ² and 10000 ² following ranges: 35 pieces, large and 50000 ² the range from 10000 ^2: 56 pieces, greater than 50000 ² and 200000Myuemu ² following ranges: was nine.

Example 2, compared similar sheet-like sintered body as in Example 1, further anodizing (electrolytic solution CuSO ₄ 5 wt%, Voltage 90V) is colored by performing an oxidation process under the condition of, problems with inspection step The one that did not exist was a porous sintered body (thickness: 0.17 mm, porosity: 86.5%). In Example 3, a porous metal body (thickness: 0.22 mm, porosity: 89.9%) was obtained in the same manner as in Example 2 except that the voltage was set to 60 V under the conditions of the oxidation step. In Example 4, a porous metal body (thickness: 0.19 mm, porosity: 90.2%) was obtained in the same manner as in Example 2 except that the voltage was set to 70 V under the conditions of the oxidation step. The porous sintered body of Example 2 was blue, the porous sintered body of Example 3 was orange, and the porous sintered body of Example 4 was cherry-colored. The porous sintered body of Example 1 is silver-white (metal titanium color). The porous metal bodies of Examples 2 to 4 had substantially the same projected area and number of pores as those of Example 1.

(Comparison example)
In Comparative Example 1, Japanese paper (Awa Japanese paper, silver Japanese paper, W-16) having a thickness of 0.17 mm, a length of 250 mm, and a width of 100 mm was used.
In Comparative Example 2, Japanese paper (Awa Japanese paper, Ganhide paper (handmade)) having a thickness of 0.16 mm, a length of 250 mm, and a width of 100 mm was used.

Comparative Example 3 is a mesh-shaped stainless steel mesh (stainless steel mesh 40), thickness: 0.39 mm, length: 250 mm, width: 100 mm, opening: 0.425 mm, porosity: 42%, wire diameter: 190 μm, gap. Rate: 73.4%.
Comparative Example 4 is a mesh-shaped stainless mesh (stainless steel mesh 80), thickness: 0.27 mm, length: 250 mm, width: 100 mm, opening: 0.18 mm, porosity: 31%, wire diameter: 120 μm, voids. Rate: 53.7%.
The above spatial ratio is a value obtained by: ((opening) × (opening)) ÷ ((opening + wire diameter) × (opening + wire diameter)) × 100.
FIG. 8 shows the SEM images of the Japanese paper and the stainless mesh of Comparative Examples 1 to 4 in which the brightness was maximized (255). The Japanese paper was subjected to Pt vapor deposition to prevent charge-up (ensuring conductivity), and then an SEM image was obtained.

In Comparative Example 5, an orange cellophane having a thickness of 0.02 mm, a length of 250 mm, and a width of 100 mm was used.
In Comparative Example 6, a blue cellophane having a thickness of 0.02 mm, a length of 250 mm, and a width of 100 mm was used.

The projected area of the hole was determined by the same method as in Example 1 (average value of 5 fields of view). The results are as follows.
Washi Comparative Example 1 did not present large and 200000Myuemu ² following holes than 50000 ^2. The maximum number / minimum number of holes in Comparative Example 1 was 24.5.
Washi Comparative Example 2 is greater than 1000 .mu.m ^2, that is, the hole in the large and 200000Myuemu ² the range from 1000 .mu.m ² did not exist.
Stainless steel mesh is larger than 1000 .mu.m ² and 5000 .mu.m ² or less in the range of comparative example 3, and only the hole of the large and 50000 ² the range from 10000 ² was present.
The stainless steel mesh of Comparative Example 4 had only holes in the range larger than ^{5000 μm 2} , that is, ^{larger than 5000 μm 2.} Since the stainless steel mesh of Comparative Example 4 has a large mesh size, there are many holes of ^{300,000 μm 2 or more.}
In Comparative Examples 5 to 6, there are no holes.

(Evaluation)
Using each of Examples 1 to 4 and Comparative Examples 1 to 6, lighting ornaments having a cylindrical container as shown in FIGS. 4 to 5 were produced, and from a light bulb of a light source arranged on the lower side of the bottom of the cylindrical container. , FIG. 9 and FIG. 10 were irradiated with light, and an image was taken in a dark room. Here, the camera: Sony α200, shutter speed: 0.8 s, squeeze: 9.0, distance between the camera lens and the light bulb: 30 cm, acrylic type: Sumipex E extruded material (composition: PMMA, thickness: 2 mm, total light transmittance: 92.6 (JIS K7361-1: 1997), refractive index: 1.49 (JIS K7105: 1981)), type of LED bulb: 3W white power LED with heat dissipation substrate. Specifications of LED bulbs, the nominal current (I _F): 70mA, the forward voltage drop (V _F): 3.5-4.5V, total luminous flux: 180-200Lm, color temperature (CCT): 6500K, chromaticity coordinates : x = 0.31, y = 0.33 , P D: is 3150mW.
Image analysis was performed on each of these images to determine the pixel brightness distribution, and the results shown in FIGS. 11 and 12 were obtained. In the image analysis, 718953 (the number of pixels on the vertical axis is 1101 and the number of pixels on the horizontal axis is 653) pixels in the area shown by the square frame in FIG. 9E are targeted, and the brightness is V = 0.299 ×. It was calculated as R + 0.587 × G + 0.114 × B. Here, (R, G, B) takes a value of 0 to 255.

From FIGS. 9 (a) to 9 (d), it can be seen that the porous metal bodies of Examples 1 to 4 shine so as to give a kind of soft impression when irradiated with light. It is considered that this is due to the reflection of light by the titanium-containing fibers that partition the pores of various sizes of the porous metal body. Further, since the porous metal bodies of Examples 1 to 4 allow light to pass through such holes, they have an appropriate strength as compared with the Japanese papers of Comparative Examples 1 and 2 shown in FIGS. 10 (a) and 10 (b). The intensity of the light is obtained.
In the Japanese papers of Comparative Examples 1 and 2 shown in FIGS. 10 (a) to 10 (b), there is no intensity of light as a whole. In other words, the lighting was blurry with no contours.
In the stainless steel meshes of Comparative Examples 3 and 4 shown in FIGS. 10 (c) to 10 (d), the area near the light source on the lower side shines particularly strongly, whereas the part on the upper side away from the light source shines weakly. .. On the other hand, in the porous metal bodies of Examples 1 to 4, light is dispersed to the upper portion away from the light source and emits a good shine as compared with the stainless meshes of Comparative Examples 3 and 4.
In addition, the porous metal bodies of Examples 1 to 4 have finer points of brilliance than the cellophane of Comparative Examples 5 and 6 shown in FIGS. 10 (e) to 10 (f), creating a unique visual impression. It can be said that it is.

From FIGS. 11 (a) to 11 (d), it can be seen that pixels are present in a relatively wide range of luminance in each of Examples 1 to 4.
In Example 1, the ratio of the number of pixels having a luminance V greater than 50 and in the range of 75 or less: the ratio of the number of pixels existing but less than 0.1% and having a luminance V greater than 75 and in the range of 100 or less: Percentage of pixels present but less than 0.1%, with brightness V greater than 100 and in the range 125 or less: 0.6%, Luminance V greater than 125 and in the range 150 or less: Percentage of pixels 2.1%, the ratio of the number of pixels in the range of brightness V greater than 150 and 175 or less: 5.8%, the ratio of the number of pixels in the range of brightness V greater than 175 and 200 or less: 11.7% The ratio of the number of pixels having a brightness V greater than 200 and in the range of 225 or less: 20.0%, the ratio of the number of pixels having a brightness V greater than 225 and in the range of 250 or less: 35.0%, and the brightness V The percentage of pixels in the range greater than 250 and less than or equal to 275: 24.8%.
In Example 2, the ratio of the number of pixels having a luminance V greater than 50 and in the range of 75 or less: 1.4%, and the proportion of the number of pixels having a luminance V greater than 75 and in the range of 100 or less: 4.2%. The ratio of the number of pixels in the range where the brightness V is greater than 100 and 125 or less: 7.6%, the ratio of the number of pixels in the range where the brightness V is greater than 125 and 150 or less: 10.8%, the brightness V is Percentage of pixels greater than 150 and in the range 175 or less: 12.8%, Luminance V greater than 175 and in the range 200 or less: 13.9%, Luminance V greater than 200 and Percentage of pixels in the range of 225 or less: 17.1%, Luminance V greater than 225 and in the range of 250 or less: 27.6%, Luminance V greater than 250 and range of 275 or less The ratio of the number of pixels in was 4.6%.
In Example 3, the ratio of the number of pixels having a luminance V greater than 50 and in the range of 75 or less: 1.4%, and the proportion of the number of pixels having a luminance V greater than 75 and in the range of 100 or less: 3.9%. The ratio of the number of pixels in the range where the brightness V is greater than 100 and 125 or less: 7.2%, the ratio of the number of pixels in the range where the brightness V is greater than 125 and 150 or less: 10.8%, the brightness V is Percentage of pixels greater than 150 and in the range 175 or less: 13.9%, Luminance V greater than 175 and in the range 200 or less: 15.1%, Luminance V greater than 200 and Percentage of pixels in the range of 225 or less: 16.3%, Luminance V greater than 225 and proportion of pixels in the range of 250 or less: 24.9%, Luminance V greater than 250 and range of 275 or less The ratio of the number of pixels in was 6.5%.
In Example 4, the ratio of the number of pixels having a luminance V greater than 50 and in the range of 75 or less: 7.7%, and the proportion of the number of pixels having a luminance V greater than 75 and in the range of 100 or less: 10.6%. , Percentage of pixels with luminance V greater than 100 and in the range 125 or less: 12.4%, Luminance V greater than 125 and proportion of pixels in the range 150 or less: 12.9%, Luminance V Percentage of pixels greater than 150 and in the range 175 or less: 12.6%, Luminance V greater than 175 and in the range 200 or less: 12.2%, Luminance V greater than 200 and Percentage of pixels in the range of 225 or less: 11.6%, Luminance V greater than 225 and proportion of pixels in the range of 250 or less: 13.4%, Luminance V greater than 250 and range of 275 or less The ratio of the number of pixels in was 1.4%. In Example 4, the proportion of pixels having a brightness V of 50 or less was 5.2%.

The maximum ratio of the number of pixels in each range of brightness is 35.0% in Example 1, 27.6% in Example 2, 24.9% in Example 3, and Example 4. It was 13.4%.
The difference between the maximum pixel ratio and the minimum pixel ratio is 35.0% in Example 1, 26.2% in Example 2, 23.5% in Example 3, and 12.0% in Example 4. Met.
In Examples 2 to 4 that had undergone the oxidation step, the brightness distribution changed gently as compared with Example 1. By forming the oxide film layer by the oxidation step in this way, it is possible to emphasize the unique visual impression of the titanium-containing fiber.

In Comparative Examples 1 to 6, the portion that appeared bright as a whole or locally was conspicuous, which was far from the desired visual impression. The maximum ratio of the number of pixels is 100% in Comparative Example 1, 100% in Comparative Example 2, 28.0% in Comparative Example 3, 53.1% in Comparative Example 4, 41.8% in Comparative Example 5, and Comparative Example. 6 was 31.5%.
In Comparative Examples 3 to 4 using the stainless steel mesh, the number of pixels having a brightness V of 125 or less is too small. In Comparative Examples 5 to 6 using cellophane, although there are a large number of minute ranges, pixels are present in a wide luminance range. However, since it is not a porous material and does not use a metal material, it is considered that light transmits cellophane almost evenly, and the desired visual impression that it shines so as to give a soft impression cannot be realized. ..

1 Porous metal body 2 Titanium-containing fiber 3 Hole 11 Lighting decoration 21 Cylindrical container 21a Bottom 21b Open end face 31 Light source 32 Outer cylinder 33 Camera Tp Thickness

Claims (15)

A porous metal body having a plurality of pores partitioned between titanium-containing fibers.
The holes include at least seven types of holes of different sizes, and the seven types of holes are
A hole having a projected area larger than 50 μm ² and 100 μm ^{2 or less,}
Hole having a larger and 500 [mu] m ² or less of the projected area than 100 [mu] m ^2,
A hole having a projected area larger than 500 μm ² and 1000 μm ^{2 or less,}
Holes having a large and 5000 .mu.m ² or less of the projected area than 1000 .mu.m ^2,
Holes having a large and 10000 ² below projected area than 5000 .mu.m ^2,
Holes having a large and 50000 ² below projected area than 10000 ^2, and,
A porous metal body having holes larger than 50,000 μm ² and having a projected area of ^{200,000 μm 2 or less.} Of the seven types of holes, the ratio of the largest number of holes to the smallest number of holes (maximum number / minimum number) is 2. The porous metal body according to claim 1, which is 0 to 12.0. In the observation area where the field of view in a plan view is 3000 μm × 2210 μm, the total number of the seven types of holes is 100 to 450, and the total projected area of the seven types of holes in the observation area. The porous metal body according to claim 1 or 2, wherein the ratio is 25% to 45%. The porous metal body according to any one of claims 1 to 3, which has an oxide film layer covering the titanium-containing fiber. In the image of the porous metal body taken while irradiating the porous metal body with light, the brightness V of each pixel is set to V = 0.299 × R + 0.587 × based on the RGB color model. When calculated by the formula of G + 0.114 × B
Pixels whose luminance V is greater than 50 and less than or equal to 75,
Pixels whose luminance V is greater than 75 and less than or equal to 100,
Pixels whose luminance V is greater than 100 and less than or equal to 125,
Pixels whose luminance V is greater than 125 and less than or equal to 150,
Pixels whose luminance V is greater than 150 and less than or equal to 175,
Pixels with a luminance V greater than 175 and in the range of 200 or less,
Pixels with a luminance V greater than 200 and less than or equal to 225,
There are pixels with a luminance V greater than 225 and in the range of 250 or less, and pixels with a luminance V greater than 250 and in the range of 275 or less.
Claim 1 in which the difference between the maximum ratio having the largest ratio of the number of pixels and the minimum ratio having the smallest ratio of the number of pixels among the ratios of the number of pixels of the pixels in each range is 8% to 40%. The porous metal body according to any one of 4 to 4. The porous metal body according to claim 5, wherein the maximum ratio is 40% or less. The porous metal body according to any one of claims 1 to 6, which forms a sheet having a thickness of 0.1 mm to 0.4 mm. The porous metal body according to any one of claims 1 to 7, which is used for lighting ornaments. Lighting ornament provided with the porous metal body according to any one of claims 1 to 8. A lighting device including the lighting accessory according to claim 9 and a light source. A method for producing a plurality of titanium-containing fibers bonded to each other in different directions and a porous metal body having a plurality of pores partitioned between the titanium-containing fibers.
A fiber deposition step of depositing a plurality of titanium-containing fibers, a sintering step of bonding the titanium-containing fibers deposited in the fiber deposition step to each other by sintering to obtain a sintered body of the titanium-containing fibers, and the above-mentioned Check the thickness of the sintered body and the projected area of the pores, and select a ^{sintered body whose thickness is within ± 30% of the target thickness and whose projected area is larger than 200,000 μm 2 and which} has no pores. A method for producing a porous metal body, which includes an inspection step. The method for producing a porous metal body according to claim 11, further comprising a thickness adjusting step of performing press working or roll rolling on the sintered body after the sintering step. The method for producing a porous metal body according to claim 11 or 12, further comprising an oxidation step of performing an oxidation treatment on the titanium-containing fibers of the sintered body after the sintering step. The method for producing a porous metal body according to any one of claims 11 to 13, wherein the titanium-containing fiber having a polygonal cross-sectional shape is used in the fiber deposition step. The method for producing a porous metal body according to any one of claims 11 to 14, wherein a titanium-containing fiber having a length of 1 to 9 mm is used in the fiber deposition step.

Images