JP5057551B2 - Zr-based metallic glass sheet - Google Patents

Description

    The present invention relates to a Zr-based metallic glass sheet material having a small amount of crystals.

  Amorphous alloys are applied as members of various products because atoms are not regularly arranged and are excellent in properties such as strength, magnetic properties, and corrosion resistance. Furthermore, in recent years, an amorphous alloy having a smaller amount of crystals has been demanded from the viewpoint of improving the quality of products.

The amorphous alloy is obtained by rapidly cooling a molten metal glass material (hereinafter also referred to as a melted raw material) at a speed equal to or higher than a cooling rate (critical cooling rate) at which it becomes amorphous. ) Is solidified (amorphized) in an amorphous state without being formed. In many cases, the critical cooling rate is about 10 ⁴ to 10 ⁷ ° C./s. Therefore, an amorphous alloy can be obtained by a gas atomization method (see Patent Document 1), a single roll method, a twin roll method, a rotary liquid spinning method, or the like. In order to manufacture the film, the thickness and size had to be several hundred microns or less, and the shape was limited to thin ribbons, ultrafine wires, fine powders, and the like.

In contrast, in recent years, Ti, Zr, Hf (elements belonging to group IVb of the periodic table), Al, Ga, B (elements belonging to group IIIb of the periodic table), Y, rare earth elements (periodic table) An active element such as Be, Mg (elements belonging to Group IIa of the periodic table) and Si as main components or synthetic components, and cooling at about 10 to 10 ⁴ ° C / s. speed (critical cooling rate) can be prepared in metallic glass material (e.g. Zr ₅₅ Cu ₃₀ Ni ₅ Al ₁₀ alloy, Mg ₅₀ Ni ₃₀ Y _{20 alloy, Ti 50 Cu 25 Ni 15 Sn} 5 Zr 5 alloy, Zr ₄₁ Ti ₁₄ Cu ₁₃ Ni ₁₀ Be ₂₂ alloy, Fe ₇₂ Al ₅ Ga ₂ P ₁₁ C ₆ B ₄ alloy, etc.) have been found (Patent Document 2 etc.).

  In Patent Document 3 and Patent Document 4, a ceramic crucible container or a water-cooled copper hearth (melting container) is used in a vacuum or an inert gas atmosphere to melt by a method such as induction heating, arc heating, or plasma arc heating. A metallic glass shaped material obtained by injecting and solidifying a raw material into a mold is disclosed.

In Patent Document 5, the cooling process is divided into two stages (first quenching zone and second quenching zone). In the first quenching zone, the molten raw material is cooled to the melting point ± 100 ° C. and further cooled in the second quenching zone. The metal glass raw material obtained in this way is disclosed.
Japanese Patent Laid-Open No. 1-233048 JP 7-252559 A JP 2001-62548 A JP 2000-271730 A Japanese Patent No. 2815215

  In order to efficiently cut out a member from a plate-shaped metal glass element (hereinafter also referred to as “metal glass plate”), a plate having a dimension as large as possible (large in both the length direction and the width direction) is preferable.

  Each of the metallic glass shapes described in Patent Documents 3 and 4 is a relatively small slab, and in the methods described in Patent Documents 3 and 4, a process of injecting a molten raw material into a mold Because of this, solidification proceeds one after another (hereinafter, also referred to as “poor filling property”), so that a plate having a large size was not obtained.

  Patent Document 5 discloses a metal glass plate material obtained by injecting a molten raw material into a mold by a normal casting method (hereinafter also referred to as “gravity casting method”) and then cooling in two stages. However, in the manufacturing method described above, since the filling property is deteriorated as the plate thickness is reduced, a plate member having a large size has not been obtained.

  The inventors also examined a plate material manufactured by producing a mold having a gap of 1 to 2 mm and injecting a molten raw material into the gap by centrifugal force. However, in this method, the injection flow is disturbed by the centrifugal force, and a hot water flow pattern (hereinafter sometimes referred to as “bath”) is seen on the surface layer portion of the obtained plate material. As a result of X-ray diffraction, it was a portion where crystals were easily generated. Therefore, in the above method, a plate material having a low crystal content has not been obtained.

  In addition, the La-based metallic glass sheet material obtained by the manufacturing method (belt casting method, twin-roll casting method, single-roll casting method, etc.) using the roll disclosed in Example 2 of Patent Document 5 is also examined. saw.

In Example 2 of Patent Document 5, the La-based metallic glass material (La ₇₀ Ni ₁₀ Al ₂₀ ) is rapidly cooled to the melting point (Tm) ± 100 ° C. of the metallic glass material in the first cooling zone. Disclosed is a long metallic glass sheet having a thickness of 1.2 mm and a width of 6.3 mm, which is manufactured by two-stage cooling in which the molten metal cooled in the two cooling zones is further cooled by a cooling roll.

  However, in the manufacturing method described in Example 2 above, it is preferable to take as much heat of the molten metal as possible in the first cooling zone, and when the molten metal is introduced from the first cooling zone to the second cooling zone. By passing through a narrowed path as much as possible, heat release is accelerated and a large amount of heat is taken away. In order to obtain a wide plate material, a wide and uniform hot water flow is required. However, it is difficult to form a wide hot water flow in the cooling zone. Therefore, the width of the plate material of Example 2 was 6.3 mm. That is, the plate obtained by the manufacturing method of Example 2 of Patent Document 5 is long but has a limit in width.

  Then, the present inventors made it a subject to provide a large Zr-based metallic glass sheet material with a small crystal content.

Zr-based metallic glass sheet material which solves the above _{problems, Zr 55 Al 20 Ni 25,} Zr 66 Al 8 Cu 12 Ni 14, Zr 65 Al 7.5 Ni 10 Cu 17.5, Zr 60 Al 10 Ni 10 Cu 15 Pd 5, Zr 55 Al ₁₀ Cu ₃₀ Ni ₅ , Zr _52.5 Ti ₅ Al _12.5 Cu ₂₀ Ni ₁₀ , Zr ₆₀ Al ₁₀ Co ₃ Ni ₉ Cu ₁₈ , or (Zr ₅₅ Al ₁₀ Cu ₃₀ Ni ₅ ) -Y ₁ Among the Zr-based metallic glass plates represented, in a material having a critical cooling rate lower than 10,000 K / s, the thickness is 0.5 mm or more, less than 2 mm, the width is 150 mm or more, and the length is 150 mm or more, and the crystal content is It is characterized by being 30% or less.

The Ti-based or TiCu-based metallic glass sheet as described above supplies the molten raw material of the Zr-based metallic glass sheet to the gap between the twin rolls at a temperature higher than the melting point of the sheet,
The raw material is taken out at a temperature within the range of glass transition temperature to glass transition temperature + 250 ° C. of the plate material,
The raw material can be produced by suppressing the spread in the width direction of the raw material generated by passing through the gap to 20% or less.

  Since the Zr-based metallic glass plate material of the present invention has a small crystal content and a large size, the member can be cut out from the plate material without waste, and the manufacturing cost of the member can be reduced.

  The Zr-based metallic glass sheet material of the present invention contains more Zr than other elements in the alloy. In addition to Zr, IVb group elements (Ti, Hf; except Zr), Vb group elements (V, Nb, Ta), VIb group elements (Cr, Mo, W), VIIb group elements (Mn, etc.), VIIIb group elements (Fe, Co, Ni, Pd, etc.), Ib group elements (Cu other), IIIa group elements ( It contains one or more elements selected from the group consisting of Al et al., IVa group elements (Si et al.), IIIb group elements (Y, lanthanum series elements, etc.) and the like.

The Zr content is 45% by mass or more (preferably 50% by mass or more) with respect to the entire alloy, although it varies depending on the element to be contained other than Zr. _{Specifically, Zr 55 Al 20 Ni 25,} Zr 66 Al 8 Cu 12 Ni 14, Zr 65 Al 7.5 Ni 10 Cu 17.5, Zr 60 Al 10 Ni 10 Cu 15 Pd 5, Zr 55 Al 10 Cu 30 Ni 5, Zr _52.5 Ti ₅ Al _12.5 Cu ₂₀ Ni ₁₀ , Zr ₆₀ Al ₁₀ Co ₃ Ni ₉ Cu ₁₈ , (Zr ₅₅ Al ₁₀ Cu ₃₀ Ni ₅ ) -Y _1, etc., among which Zr ₅₅ Cu ₃₀ Ni ₅ Al ₁₀ etc. The Zr-based alloy is particularly preferable.

As the thickness of the plate material increases, the strength of the plate material increases, but it becomes difficult to cool the molten raw material below the critical cooling temperature during the production process. For example, even a Zr ₅₅ Cu ₃₀ Ni ₅ Al ₁₀ alloy, which is relatively easy to vitrify, tends to generate crystals in the plate material when the thickness exceeds 3 mm. Therefore, in consideration of the strength of the plate material and the easiness of vitrification, the plate thickness needs to be 0.5 mm or more (preferably 0.8 mm or more) and less than 2 mm.

  The dimensions (length and width) of the Zr-based metallic glass plate material are required to be at least 100 mm (preferably 150 mm or more, more preferably 200 mm or more) from the viewpoint of use as a practical structural material.

  In addition, the amount of crystals (crystal content) present in the Zr-based metallic glass sheet is 30% or less (preferably 20% or less, more preferably 10% or less) from the viewpoint of preventing breakage that occurs from the crystal as a starting point. It is necessary to suppress. The method for measuring the crystal content can be obtained by subjecting a part of the plate material to X-ray diffraction and calculating from the ratio of the area of the crystal peak to the total area surrounded by the diffraction curve and the baseline from the obtained diffraction diagram. it can.

The cooling rate at the time of producing the plate material can be determined by the following general formula (1) from the Tg and Tm of the alloy and the time required for solidification of the alloy.
Cooling rate = (Tm−Tg) / (required solidification time) (1)

  The calculation method of Tg and Tm is not particularly limited, and can be measured using a differential scanning calorimeter (DSC) or the like.

The solidification time varies depending on the plate thickness, and generally, the following formula (2) is established between the growth distance (X) of the solidification interface and the solidification time (t).
X = A√t (2)
(A: Constant)

  In order to calculate the above A (constant), for example, a molten raw material is poured into a copper mold and allowed to stand to produce an ingot (eg, an ingot having a thickness of 2 mm, 4 mm, or 6 mm), and chromel Using an alumel (K) sheathed thermocouple, the time required for the ingot to solidify naturally from the melting point (Tm) to the vicinity of the glass transition temperature (Tg) is measured. Then, A (constant) in the general formula (2) is calculated from the thickness of the ingot (corresponding to the growth distance (X) of the solidification interface) and the solidification time (t).

  Next, the value of A (constant) obtained above is substituted into formula (2), and the time required for solidification (t) corresponding to the desired thickness of Ti-based metallic glass sheet [corresponding to growth distance (X)] is obtained. calculate. The value of the required solidification time (t) and the values of Tm and Tg of the Ti-based metallic glass plate material are substituted into the general formula (1), and the critical cooling rate at the plate thickness is calculated. Since solidification usually proceeds from both sides of the plate, the growth distance (X) of the solidification interface is calculated as ½ of the thickness of the ingot (for example, if the plate is 4 mm thick, X is calculated as 2 mm). .

FIG. 1 shows the relationship of the formula (2) in a Zr ₅₅ Cu ₃₀ Ni ₅ Al ₁₀ alloy that is relatively easy to vitrify among Zr-based metallic glass sheets, and the horizontal axis indicates the time required for solidification (t), and the vertical axis indicates The graph is obtained by taking the solidification interface growth distance (X), the value of A (constant) is 1.85, and the time required for solidification when the thickness is 0.5 mm is 0.018 seconds [t = ( 0.5 / 2) ² /1.85 ² = 0.018].

Tm of the Zr ₅₅ Cu ₃₀ Ni ₅ Al ₁₀ alloy is 880 ° C. (about 850 to 1000 ° C. in a general Ti-based metallic glass material), and Tg is 420 ° C. (in a general Ti-based metallic glass material, The Tm-Tg value is 460 ° C. (400 to 600 ° C. for a general Ti-based metallic glass material). Therefore, the cooling rate from 880 ° C. to 420 ° C. is 25600 K / s in the Zr ₅₅ Cu ₃₀ Ni ₅ Al ₁₀ alloy plate material having a thickness of 0.5 mm. When the plate thickness is 2 mm, the time required for solidification is 0.29 seconds, and the cooling rate is 1600 K / s.

It has been found that a Zr ₅₅ Cu ₃₀ Ni ₅ Al ₁₀ alloy, which is a typical Zr-based metallic glass plate material, is vitrified to a thickness of about 3 mm even by a casting method. The cooling rate is about 700 K / s, so the critical cooling rate is 700 K / s. If the cooling rate of the 2 mm plate is 1600 K / s, the critical cooling rate is higher than 700 K / s, which indicates that it can be vitrified sufficiently. If a plate material is made using a metal glass material having a critical cooling rate of about 1000 K / s, which is difficult to vitrify, on the contrary, if the plate thickness is 0.5 to 0.8 mm, a vitrified plate material can be produced.

The Zr-based metallic glass sheet material is not particularly limited as long as the above characteristics can be obtained, but the present inventors have investigated that a Zr ₅₅ Cu ₃₀ Ni ₅ Al ₁₀ alloy is produced by a gravity casting method. Then, it turned out that there is a limit in the dimension of the board | plate material obtained by board thickness (following Table 1). This is because when the plate thickness is thin, it is necessary to reduce the gap between the molds and solidify before the molten metal is filled.

  Therefore, as a result of intensive studies by the present inventors, the twin-roll method in which the molten raw material of the Zr-based metallic glass sheet material is cooled through the gap between the twin rolls (different from the method of Example 2 of Patent Document 5 described above). It was found that the Zr-based metallic glass sheet of the present invention can be suitably produced by using the method.

  A plate material obtained by crystallizing a crystal phase in the plate material if the temperature at which the molten raw material is supplied to the gap between the rolls (hereinafter also referred to as “cooling start temperature”) is less than the melting point (Tm) of the Zr-based metallic glass plate material. The amount of crystals increases. Furthermore, the molten raw material is solidified in a short time in the process of cooling the molten metal in contact with the roll, and “cracking” occurs when passing through the gap, making it difficult to obtain a plate having a large size. Therefore, the cooling start temperature needs to be higher than the melting point (Tm) of the Zr-based metallic glass sheet.

  The higher the cooling start temperature is, the lower the probability that the crystal phase is crystallized, and it becomes easier to obtain a plate material with a small amount of crystals, and the possibility of “cracking” in the cooling process is reduced. Therefore, it is preferable that the cooling start temperature is Tm + 100 ° C. or more, and Tm + 130 ° C. or more. In the manufacturing stage, temperature unevenness may occur between the center and both ends of the plate. For this reason, even if the temperature at the center is near the melting point, the both ends are below the melting point, and crystals may crystallize at both ends. Also from the above viewpoint, the cooling start temperature is preferably set to Tm or higher. However, if the cooling start temperature is too high, the cooling rate must be increased in order to set the temperature taken out from the gap between the rolls (hereinafter referred to as “cooling end temperature”) to a temperature described later. Therefore, it is preferable that the cooling start temperature is Tm + 200 ° C. or lower, preferably Tm + 170 ° C. or lower.

  The molten raw material is cooled while passing through the gap between the rolls and simultaneously formed into a plate shape. At that time, the lower the cooling end temperature, the solidification proceeds, and the obtained plate material lacks in flatness and smoothness, and further processing / shaping becomes difficult. Moreover, when using a copper roll for a roll, a part of board | plate material damaged and solidified adheres to the roll surface, and workability | operativity will fall. Therefore, the cooling end temperature is preferably not less than the glass transition temperature (Tg) of the Zr-based metallic glass sheet material, and more preferably not less than Tg + 20 ° C. The higher the cooling end temperature is, the easier the subsequent processing / shaping becomes, but if it is too high, the cooling will be insufficient, and the crystal phase will crystallize after taking out from the gap between the rolls, making it difficult to obtain a plate material with few crystals. Become. Therefore, the cooling end temperature needs to be Tg + 250 ° C. or lower (more preferably Tg + 200 ° C. or lower, more preferably Tg + 150 ° C. or lower).

  The cooling end temperature can be adjusted by the peripheral speed of the roll. Depending on the composition of the plate material, the size of the gap between the rolls and the temperature of the molten raw material supplied to the gap between the rolls, the lower the peripheral speed of the roll, the longer the state that the molten raw material stays in the roll part, Crystals begin to crystallize, and the accompanying solidification latent heat is released, so that a sufficient cooling effect cannot be exhibited. Therefore, the peripheral speed of the roll is preferably 0.1 m / s or more (preferably 0.15 m / s or more, more preferably 0.25 m / s or more). As the peripheral speed of the roll increases, the thickness of the plate material decreases, and it becomes difficult to obtain a Zr-based metallic glass plate material having a uniform and sufficient thickness. Therefore, the peripheral speed of the roll is preferably 1.5 m / s (preferably 0.75 m / s) or less.

The relationship between the peripheral speed of the roll and the thickness of the obtained plate material is as shown in Table 2 when a plate material of Zr ₅₅ Cu ₃₀ Ni ₅ Al ₁₀ alloy is taken as an example.

  In addition, when the melted raw material passes through the gap between the rolls and spreads in the width direction, a hot water boundary or hot water flow pattern is generated at both ends of the extracted plate material, or large irregularities are formed on the surface. In the region, crystals are easily formed. Therefore, the spread in the width direction needs to be suppressed to 20% or less (preferably 15% or less, more preferably 10% or less). In order to suppress the spread in the width direction, for example, the molten raw material is supplied to the gap between the rolls through a nozzle, and the width of the nozzle is 0.83 times or more (preferably the width of the desired plate material) Is 0.9 times or more) and can be performed by setting the size to 1 time or less.

  As an apparatus used in the above manufacturing method, an apparatus as shown in FIG. In the figure, 1 shows a melting furnace for obtaining a molten raw material by melting the raw material of the Zr-based metallic glass plate, 2 shows a roll part for cooling the molten raw material, and the roll part is At least two rolls of a lower roll 5 and an upper roll 6 are provided.

  A tundish (nozzle) 3 is arranged as a mechanism for supplying the molten raw material melted in the melting furnace 1 to the gap between the rolls of the roll unit 2. By arranging the above mechanism, the flow of the molten raw material is rectified, the induction of excessively turbulent vortex flow that occurs when the molten raw material approaches the roll is prevented, and the crystal induction is suppressed, making it more stable and longer. A plate material with a scale can be obtained. The tundish 3 preferably has a mechanism (heater 12) that can heat the inside of the tundish 3 in order to suppress cooling of the molten raw material supplied to the inside. In FIG. 2, the melting furnace 1 is tilted and the molten raw material is transferred to the tundish 3 via the receiving part 8. In addition, a valve that can be opened and closed around the bottom of the melting furnace 1, etc. Displacement outlets are arranged, and the exclusion opening and the tundish 3 are connected via a cradle or the like, and the molten material in the melting furnace 1 is tanned while adjusting the supply amount according to the degree of opening and closing of the valve. A mechanism for transferring to the dish 3 may be used.

  Further, in order to suppress the spread in the width direction to 20% or less, the width of the nozzle disposed at the tip of the tundish portion is 0.83 times or more (preferably 0.9 times or more) with respect to the width of the desired plate material. ) It is preferable to set the size to 1 or less.

  The Zr-based metallic glass sheet taken out from the gap of the roll part 2 may be taken out as it is, but may be provided with a slab collecting table 4 for conveying the taken-out Zr-based metallic glass sheet. The slab collection platform is preferably a mechanism that can transport the plate material without applying an excessive load, such as a frame-like mechanism in which small rolls are arranged, a heat-resistant rotating belt (for example, a steel thin plate) mechanism, or the like. Can be adopted. These mechanisms can be operated by a driving mechanism such as a motor. The transport speed is preferably a speed corresponding to the speed at which the Zr-based metallic glass sheet material is taken out from the gap between the rolls. Further, when a rolling effect is generated in the cooling process, the speed of taking out from the roll becomes faster than the peripheral speed of the roll. In that case, the conveyance speed may be controlled and adjusted to be faster than the peripheral speed of the roll.

  Furthermore, in the production method of the present invention, the cooling end temperature is set higher than Tg of the Zr-based metallic glass material and lower than Tg + 250 ° C., so that viscous flow molding is possible, and the Zr-based metallic glass material taken out from the gap The shape and / or dimensions can be adjusted using a straightening roll or the like until the temperature becomes Tg or less. For this reason, it is also preferable to have a shaping correction mechanism 7. The correction mechanism may be a mechanism that adjusts the shape by passing between a plurality of rolls as shown in FIG. 2, or a mechanism that presses a plate-like object.

  In addition, if a foreign substance such as an oxide is present in the element used in the production method of the present invention, crystallization is likely to occur with the foreign substance as a starting point, so the inside of the apparatus is in a vacuum state or an inert gas (Ar gas or It is preferable to be in a state filled with He gas or the like. In order to perform cooling more effectively, a gas (inert gas such as Ar or N) may be blown onto the Zr-based metallic glass plate or roll to be taken out to increase the cooling rate of the plate.

In this example, using the apparatus of FIG. 3, under the conditions shown in Table 1, ZX1 [Zr ₅₅ Cu ₃₀ Ni ₅ Al ₁₀ ; Tm = 880 ° C. (measured value at melting), Tg = 420 ° C.] and ZX2 Two types of Zr-based alloys of [Zr ₅₃ Cu ₂₀ Ni ₁₀ Al ₁₂ Ti ₅ ; Tm = 860 ° C. (measured value at the time of melting), Tg = 400 ° C.] were produced.

  The manufacturing apparatus shown in FIG. 3 is for supplying the molten raw material to the melting furnace 1, the receiving part 8 for tilting the melting furnace 1 to supply the molten raw material in the melting furnace 1 to the tundish 3, and the roll part 2. The tundish (dotted line part) 3, the roll part 2, and the slab collecting base 4 for collecting the Zr-based metallic glass sheet cooled through the roll part 2 are formed, and the entire apparatus forms a vacuum state.・ It is installed in a vacuum chamber so that it can be maintained.

  The melting furnace 1 is a high-frequency induction melting furnace made of a graphite crucible, and 10 to 25 g of a Zr-based metallic glass material can be melted at a time by a high-frequency power source (frequency 3000 Hz, maximum output 400 kW). . In the graphite crucible 1, a platinum-rhodium thermocouple (R) 9 for measuring the temperature of the molten raw material (including a protective tube in which the outer periphery of the alumina protective tube is covered with a protective tube made of graphite). The temperature at the time of melting of the molten raw material can be measured.

  In order to heat the inside of the tundish 3, the tundish 3 is provided with a heater 12 on the outer surface and a sheath-type chromel alumel (K) thermocouple 9 is provided on the inside, and the temperature of the molten raw material in the tundish Can be measured. Furthermore, the tip of the tundish (portion close to the roll) is configured so that the molten metal flows uniformly from the inside through a slit having a width of about 5 mm, and the width of the tip of the tundish (nozzle) is 100 to 270 mm. It can be adjusted to.

  The roll unit 2 is a horizontal twin-roll device having an upper roll 5 and a lower roll 6. The upper and lower rolls are both copper-cooled rolls having a diameter of 400 mm and a width of 270 mm, and each can be adjusted by being driven individually by a servo motor.

  The slab collection base 4 is composed of a caterpillar-shaped transport mechanism arranged so as to be close to the roll unit 2, and the transport speed of the caterpillar can be set in a range of 0.1 to 3 m / s, and the peripheral speed of the roll The structure can be adjusted to match.

  Further, the temperature of the Zr-based metallic glass plate taken out from the gap between the rolls can be measured by the radiation thermometer 11 from outside the chamber through the viewing window 10.

  The raw material of the Zr-based metallic glass plate material is melted by a cold crucible induction melting method using a water-cooled copper crucible, and after adjusting the alloy components, the molten metal is poured onto the copper plate to form a plate-shaped ingot having a thickness of about 10 mm. It was made by solidification. It was confirmed that the obtained ingot had an oxygen content of 0.1% by weight or less, a carbon content of 0.1% by weight or less, and a nitrogen content of 0.05% by weight.

  Then, 10 kg of the raw material is put into a melting furnace (graphite crucible) 1 and high-frequency induction heating is performed to melt the raw material. Then, after evacuating the atmosphere in the chamber once, Ar gas is put back and adjusted to a reduced pressure of 100 to 400 Torr (usually 200 Torr), and then the raw material is dissolved by setting the output of the high frequency power source to 100 kW. At that time, the temperature of the molten raw material is confirmed by the thermocouple 9 and the output of the power source is adjusted so that the temperature of the molten metal raw material becomes the temperature described in Table 3.

  In addition, the maximum temperature at the time of melt | dissolution was about 1350 degreeC or less. Moreover, the temperature at which the molten raw material is cooled in the process of passing through the graphite cradle 8 is 1300 ° C. to 1100 ° C., which is slightly lower than the maximum temperature.

  In “Evaluation of plate formation” in Table 3, “Δ” means a plate material having a non-uniform width, whereas “◯” means that a plate material was stably formed.

  The “crystal content” in Table 3 was calculated by the following method. First, from the obtained twin-roll plate material, a square (a part to be actually used) is cut out with the end portion remaining. And from the remaining part, the part (one point for each side, a total of four points) that was close to each side of the cut out rectangle was sampled, and a RAD-RU300 X-ray diffractometer manufactured by Rigaku Corporation was used at each point. X-ray diffraction. From the obtained diffraction diagram, the area (total area) of the portion surrounded by the diffraction curve and the baseline and the area of the crystal peak were measured to calculate the crystal ratio [crystal content (%) = (area of the crystal peak ) / (Total area) × 100].

  Specifically, using the results of FIG. 4, the above-mentioned “crystal peak area” means the area of the portion corresponding to 14 (outlined portion), and “total area” means 13 (hatched line) Part) and the area corresponding to the part which combined 14 is meant.

  In this example, the base material manufactured based on the materials shown in Table 3 is filled in the melting furnace 1 and the chamber 1 is evacuated, and the melting furnace 1 is described in “When melted” in Table 3. Dissolve at the specified temperature. Then, the melting furnace 1 was tilted, and the molten Zr-based metallic glass material inside the furnace was poured into the tundish 3 to produce a Zr-based metallic glass sheet under the conditions described in Table 3. The results are shown in Table 3.

  Experiment No. 1 in Table 3 2, 4 and 5 are Zr-based metallic glass sheets of the present invention. Reference numerals 6, 8 and 9 are plate materials given as a comparison.

  No. In the plate materials 2, 4, and 5, the formation of the plate material was stable, and the crystallization rate was 30% or less. In contrast, no. The plate material No. 6 is a plate material in which the width of the tundish nozzle is set to 70 mm and the melted raw material is expanded at the roll portion. No. In the plate material 6, many irregularities were formed at both ends, and although the metal glass plate itself was manufactured, a difference in crystal content was observed between the central portion and both ends of the obtained plate material.

  No. In the plate materials of 8 and 9, since the roll discharge part (cooling end temperature) was higher than Tg + 250 ° C., the plate material itself was formed, but the crystal content was high and there was almost no portion that could be used as a metal glass plate material. .

FIG. 1 shows the relationship between the time required for solidification of the Zr ₅₅ Cu ₃₀ Ni ₅ Al ₁₀ alloy and the growth distance of the solidification interface. FIG. 2 is a schematic cross-sectional view of an apparatus that can be suitably used for the production of the Zr-based metallic glass sheet of the present invention. FIG. 3 is a schematic cross-sectional view used for explaining the configuration of the manufacturing apparatus used in this example. FIG. 4 is a drawing used for explaining the calculation method of the crystal content of the present invention.

Explanation of symbols

1. Melting furnace 2. Roll unit Tundish4. 4. Slab collection stand Lower roll 6. 6. Upper roll Molding straightening mechanism8. Receiving part 9. Thermocouple 10. Viewing window 11. Radiation thermometer 12. Heater 13. A portion obtained by removing a portion corresponding to the crystal peak area from a portion corresponding to the total area. The portion corresponding to the crystal peak area

Claims (1)

_{Zr 55 Al 20 Ni 25, Zr} 66 Al 8 Cu 12 Ni 14, Zr 65 Al 7.5 Ni 10 Cu 17.5, Zr 60 Al 10 Ni 10 Cu 15 Pd 5, Zr 55 Al 10 Cu 30 Ni 5, Zr 52.5 Ti 5 Al _12.5 Cu ₂₀ Ni ₁₀ , Zr ₆₀ Al ₁₀ Co ₃ Ni ₉ Cu ₁₈ , or (Zr ₅₅ Al ₁₀ Cu ₃₀ Ni ₅ ) -Y ₁ Zr group characterized in that in a material having a critical cooling rate lower than 10,000 K / s, the thickness is 0.5 mm or more, less than 2 mm, the width is 150 mm or more, the length is 150 mm or more, and the crystal content is 30% or less. Metal glass plate material.