WO2018192180A1 - Forged artificial joint and novel production process and use of metal product - Google Patents

Abstract

Provided are a forged artificial joint and a novel production process of a metal product. A fine grain casting technique is directly used to manufacture a forging blank for forging production. The process comprises: Step 1: using a fine grain casting furnace to produce a fine grained forging blank for forging; Step: cleaning the produced fine grained forging blank; Step 3: placing the fine grained forging blank obtained in Step 2 in a heat treatment furnace, and heating the same; Step 4: placing the fine grained forging blank having undergone heat treatment in a forging mold, and forging the same; and Step 5: removing a forged product from the forging mold, and performing trimming and polishing to obtain a finished product. The process enables a finished product to have higher strength, hardness, wear resistance and corrosion resistance. The process of the present invention has fewer steps than existing production processes of forged metal products because it does not include steps such as cogging, rolling, and drawing, thereby reducing material and energy consumption, reducing environmental pollution, and ensuring a high testing pass rate.

Description

New production process and use of forged artificial joints and metal products Technical field

The present application relates to the technical field of forged metal products, and in particular relates to a novel production process and use of a forged artificial joint and metal products.

Background technique

It is very important to measure the quality of artificial joints. This is the strength, wear resistance and corrosion resistance. For metal artificial joints, in the case of the same alloy composition, the higher the strength of the artificial joint, the finer and more uniform the grain size of the metal structure is required; the better the wear resistance of the artificial joint, the metal mechanical properties are required. The higher the hardness; the better the corrosion resistance of the artificial joint, the higher the density of the metal material is required. Therefore, the finer the grain size of the metal structure is developed, the more uniform, the higher the hardness of the metal mechanical properties, and the higher the density of the metal material is the key to the production process of the metal artificial joint. In fact, not only metal artificial joints, but also most metal products. This patent application claims patent protection is such a new production process.

The products currently obtained in this new production process are superior in strength, wear resistance and corrosion resistance in the same kind of products. However, it is not excluded that a few similar products are higher than the products currently obtained by the new production process in one aspect or in all three aspects. However, the existing traditional production process has lost the space to further improve the quality of the product. The industry began to study the use of ceramic artificial joints as an example. However, the brittleness of ceramic artificial joints is difficult to break through and it has not been put into practical use. Metal artificial joints are still in commercial use. The new production process has, in principle, broken through the fatal limitations of traditional production processes and demonstrated the potential to unimaginably improve product quality.

It must be pointed out that industrial production in different industries can only give the true meaning of their own industry products. Actual production steps and production examples, however, for metal products, high strength, good wear resistance and good corrosion resistance are generally required. Therefore, the new production process actually provides a new process choice for the entire forging industry.

Summary of the invention

In view of the above analysis, the present application aims to provide a novel production process and use of a forged artificial joint and a metal product, and a method for directly casting a forged blank by using a deep subcooled fine crystal casting furnace to solve the existing casting. The problem of uneven grain size effectively improves product quality.

The purpose of this application is mainly achieved by the following technical solutions:

A novel production process for forging artificial joints and metal products, directly using fine crystal casting to manufacture forged blanks for forging production, specifically comprising the following steps:

Step 1. Casting a fine crystal blank for forging using a deep subcooled fine grain casting furnace;

Step 2. Cutting and grinding the whole set of fine crystal blanks to obtain a fine crystal forged blank, and then cleaning the obtained fine crystal forged blanks;

Step 3. The fine crystal forged blank obtained in the step 2 is placed in a heat treatment furnace for heating;

Step 4. The fine-grained forging blank heated in step 3 is placed in a forging die for forging;

Step 5. Take the forged product from the forging die and trim and polish it to obtain the finished product.

Further, in the step 1, the deep subcooled fine crystal casting furnace mainly comprises: a melting crucible, a mold, a constant magnetic field magnetic pole, a mold carrying turntable, and the melting crucible is located above the casting mold. The constant magnetic field magnetic pole is located around the mold, the mold carrying turntable is located at a lower end of the mold, and is fixedly connected with the mold; the melting crucible is provided with an alternating current induction coil and a direct current a steady magnetic field; the melting crucible, the steady magnetic field pole, and the mold carrying turntable are located in the casting furnace, and the mold is placed on the mold carrying turntable from outside the furnace door by equipment.

Further, the constant magnetic field magnetic pole is divided into a constant magnetic field N pole and a steady magnetic field S pole, and the stable magnetic field N pole and the steady magnetic field S pole are oppositely disposed, and the mold is located at the stable magnetic field N The pole and the steady magnetic field are in the middle of the S pole.

Further, the mold-carrying turntable is rotated slowly outside the furnace by a manual or electric method, and the mold-carrying turntable is input by a slow rotating shaft having a diameter of not less than 25 mm and not more than 65 mm, and the mold-carrying turntable Rotated by a ratchet.

Further, in the step 2, the processing of the cast blank is sand cleaning, cutting, grinding, and polishing.

Further, in the step 3, the heating temperature of the heat treatment furnace ranges from 900 ° C to 1200 ° C.

Further, in the step 4, the forged blank is swaged using a 2 to 5 ton forging hammer.

Further, the novel production process can be applied to artificial joints, all metal-type medical implants other than artificial joints, and forged metal products and mechanical parts of non-medical implants.

The use of a product prepared by a novel production process for forging artificial joints and metal products, and the prepared forged blank is used for forging medical implants.

Further, the artificial joint forged using the production process of the present application is directly used for clinical purposes.

The artificial joint production process can be divided into two types, one is cast type and the other is forged shape. It is currently recognized that the cast artificial joint is superior to the forged artificial joint, and the cast artificial joint has a coarse and uneven grain size, and the density is also poor; therefore, the forged artificial joint is the preferred process for producing high quality artificial joints.

However, the traditional forging artificial joint production process has many processes. The specific process is: firstly casting a large steel ingot, and then casting, rolling and drawing the large steel ingot into a thin rod of a certain diameter, and then The thin rod is cut into small sections, and then the small section of the thin rod is partially thickened, and then the small section of the thin rod is bent and bent into a forged blank of the forged artificial joint, and then the blank is taken for forging. Therefore, the production of forged blanks requires a large amount of high energy-intensive work. Order, and, the blanking, rolling, drawing requires multiple hoes to the tail, wasting a lot of expensive artificial joint metal materials. If casting small ingots, although the amount of blanking, rolling, drawing and boring will be less, the forging blank made of small steel ingot will not be enough deformation, so the grain size of the forged blank is not enough. It is small, so that the grain size of the final product is not small enough. Moreover, a large steel ingot is cast, and then the large steel ingot is billed, rolled, drawn into a thin rod of a certain diameter, and then the thin rod is cut into small pieces, and then the small thin rod is partially thickened, and then The grain size of the forged blank of the forged artificial joint is small, but the deformation storage energy is relatively high, and the deformation texture is fine grain structure, which has strong directionality. This results in unstable grain structure and anisotropic mechanical properties if the annealing temperature is insufficient. Generally speaking, the strength of the product is directional. For example, the longitudinal strength is high, but the lateral strength is not high. If the annealing temperature is too high, the grain size driven by the deformation storage energy will increase, and the strength will decrease.

The new production process of the present application directly casts a forged blank having a very fine and uniform grain size, and the final product forged from the blank is not only a finer grain size, but also because the fine grain of the forged blank used is balanced. The solidified equiaxed grains, therefore, have no storage energy and texture directivity due to deformation, so the metal structure is stable. In addition, compared with the traditional forging process, this new process is to forge a direct casting of the blank, so the process is less, the energy consumption is less, and the material is saved. It is also worth noting that this forging process can ensure very fine grain structure of the final product with a small amount of forging deformation. Because the original grain size of the forged blank is very small; since the solidification shrinkage of the fine-grain casting is diffused, the metal structure is also dense after forging; thus, since the amount of deformation can be small, the chemical can be used. The composition is designed with an alloy of high strength and hardness, which enables the final product to have higher strength and hardness. However, the traditional process requires large deformation of large steel ingots, rolling, and drawing. In principle, it is not possible to use alloys with high chemical strength and high hardness.

The beneficial effects of the application are as follows:

(1) The method of the present application is not only suitable for the production of metal artificial joints, but also for all metal-type medical implants other than artificial joints and forged metal products and mechanical parts of other non-medical implants, and has potential Application value;

(2) The process of the present application directly uses the fine-grain casting to manufacture the forged blank for forging production, which can make the final product have higher strength, hardness and wear resistance;

(3) Compared with similar products, the process method of the present application has less raw material consumption, less energy consumption, high product qualification rate, and is suitable for industrial production.

Through the above, it is not difficult to see that the enlightenment of the new production process is not limited to the production of metal artificial joints, and all metal-type medical implants other than artificial joints can learn from this new production process. Moreover, forging metal products and mechanical parts of other non-medical implants can also adopt a new production process. That is, the forging blank is not produced by the conventional process of casting, ingot rolling, drawing, and the like, but the production process of the forged product is directly produced by fine-grain casting.

DRAWINGS

1 is a schematic structural view of a core portion of a deep subcooled fine grain casting furnace of the present application;

Figure 2 is a grain structure of a conventional process casting blank;

Figure 3 is a grain structure of a deep subcooled fine-grained casting blank of the present application;

Figure 4 is a product produced by the novel forging process of the present application;

Figure 5 is a diagram showing the state of Na ₂ S corrosion resistance of a conventional process product;

Figure 6 is a diagram showing the state of Na ₂ S corrosion resistance of the product of the novel process of the present application.

In the figure, 1-melting 坩埚, 2-cast, 3-steady magnetic field N or S pole, 4-steady magnetic field S or N pole, 5-cast load-bearing turntable, 6-cast load-bearing turntable load-bearing wheel , 7-ratchet, 8-cast type bearing carousel rotation center positioning axis.

detailed description

The preferred embodiments of the present application are described in detail below with reference to the accompanying drawings.

The invention prepares a deep superfine fine crystal casting furnace, as shown in FIG. 1 , which mainly comprises a mold carrying turntable 5 , a mold 2 , a ratchet 7 , a casting bearing turntable rotating center positioning shaft 8 , a mold carrying turntable bearing wheel 6. Heating element, steady magnetic field magnetic pole, melting crucible 1, melting crucible 1 is located above the mold 2, mold 2 is mounted above the mold carrying turntable 5, and a mold carrying turntable is arranged under the mold carrying turntable 5. The load bearing wheel 6 and the ratchet wheel 7 are used to drive the rotation of the mold-carrying turntable 5. The heating element and the constant magnetic field magnetic pole are arranged around the mold 2, and the mold-bearing turntable is arranged at the center of the lower end of the mold-bearing turntable 5. The center of rotation positioning shaft 8 is used to define the center of rotation of the mold carrying carousel 5.

Wherein, the melting crucible 1 is a crucible having a constant magnetic field or a static magnetic field and an alternating magnetic field simultaneously and separately applied to hold and melt the master alloy, and an alternating magnetic field and an alternating induction coil are applied to the melting crucible 1 . At the same time, a separate steady magnetic field is also applied to the melting crucible 1, which is also called a static magnetic field, that is, more than one induction coil, and the static magnetic field induction coil can simultaneously have a resistive heating function, and the same type of furnace has only an alternating induction coil; In the present application, the melting crucible 1 has a structure in which the far infrared and the thermocouple are simultaneously temperature-measured, and some of the similar furnaces also have these two kinds of temperature measuring means, but cannot measure the temperature at the same time;

A magnetic pole is applied around the mold 2 to apply a constant magnetic field or a static magnetic field. The furnace of the same type is not. The closest one is to provide a winding around the mold with a pulsed magnetic field. Meanwhile, the casting furnace of the present application is around the mold 2. A magnetic strain gauge is applied to a magnetic pole to which a steady magnetic field or a static magnetic field is applied, and the attractive force F between the N-S poles can be measured at any time, so that the B-magnetic field strength can be calculated at any time by the electromagnetic field formula of F=BIL. The value of the furnace B = 1 _~ 2T (T-Tesla);

At the same time, there is a movable heating element around the mold 2. The furnace is a resistance wire, and can reach more than 1200 °C. Some furnaces of the same type have heating elements, but they are fixed and temporarily added. Less than 1200 ° C, and not the device itself;

The mold-carrying turntable 5 can be rotated slowly in the manual or electric mode outside the furnace, and can be stopped at any time to adjust the pouring position evenly to achieve multi-station pouring in the same furnace. Some of the similar furnaces have high-speed rotating mold bearing. Turntable, but that is used for centrifugal casting; the power equipment that must be rotated at high speed due to centrifugation is very large and can only be placed outside the vacuum furnace shell. Its high-speed rotating shaft is passed into the furnace from outside the furnace, and the high-speed rotating shaft pair The damage of the vacuum seal is theoretically unavoidable. There are many precedents for failure in China; the rotary transfer of the mold carrying turntable 5 is input by a slow rotating shaft with a diameter of not less than 25 mm and not more than 65 mm; The maximum time is less than 1 rev / 2 seconds, which is lower than the current ability of the vacuum equipment to rotate and seal. In fact, this is the speed at which the existing vacuum device rotates the handle, so the damage of the rotation to the vacuum seal is negligible; The rotation of the mold-carrying turntable 5 is driven by the ratchet 7 which is rotated slowly, so that the rotational speed of the mold-carrying turntable 5 can be accumulated, and when accumulated to 1 revolution/1 second, the pair of diameters of 300 mm or more The piece also has a centrifugal casting function; the mold-carrying turntable 5 of the furnace can be rotated at a slow speed is the main common function of the furnace, and the purpose is to make the heating element around the mold 2 heating the mold 2 evenly, because FIG. 2 It can be seen that there are no resistance wires on both sides of the magnetic pole; the mold-bearing turntable 5 uses a mold-bearing turntable rotation center positioning shaft 8 to define a rotation center, and the shaft does not bear the weight, and is inserted into the bottom positioning slot of the furnace, and the slot is The blind hole is not connected to the outside of the vacuum furnace; the lower part of the mold carrying turntable 5 is provided with a plurality of load-bearing wheels, that is, the mold-bearing turntable load-bearing wheel 6, and the periphery of the mold-bearing turntable 5 is a tooth ring that is rotated and transmitted, and the furnace is driven by the furnace. The externally input rotating ratchet 7 cooperates, and the ratchet shaft leads to the outside of the furnace, that is, a slow rotating shaft for transmitting power to the casting bearing shaft; and a casting type limiting pin hole is also arranged on the bearing surface of the casting carrying turntable 5, The mold 2 is inserted into the mold limit pin hole through the fixing pin;

The mold 2 is placed horizontally from the outside of the furnace door by the forklift on the mold carrying turntable 5 in the furnace, and then closed. Close the furnace door, open the furnace top cover, plug the heating element resistance wire inside the furnace door into the power supply, and the mother alloy is also placed in the furnace cover by the furnace top, and the replacement of the new concrete is also the result.

A novel production process for forging artificial joints and metal products, and the specific steps include:

Step 1. Casting a fine crystal blank for forging using a deep subcooled fine grain casting furnace;

Step 2. Sanding, cutting, grinding and polishing the cast whole set of forged fine crystal blanks to obtain fine-grained forged blanks, and then cleaning the obtained fine-grained forged blanks;

Step 3. The fine crystal forged blank prepared in step 2 is placed in a heat treatment furnace and heated to 900 ° C to 1200 ° C;

Step 4. The fine-grained forging blank heated in step 3 is placed in a forging die, and the forging is performed with a 2 to 5 ton forging hammer. After the forging is completed, the forging die is opened, and the forged artificial joint is taken out;

Step 5. Take the forged artificial joint from the forging die for trimming and polishing, and obtain the finished artificial joint, as shown in Fig. 4.

The mechanical properties and corrosion resistance of the products prepared by the present application compared with the products of the conventional forging production process are as follows. This comparison is a comparison of the mechanical properties of the old and old processes of the same alloy composition, as shown in Table 1.

Table 1. Comparison of mechanical properties of old and new processes of the same alloy composition

The corrosion resistance of the product of the present application and the current process is tested by the national standard test method for medical metal materials (national standard: GB/T 17168-1997). The initial comparison between the new process and the current process is not obvious, but is extended. After the corrosion time, there is a significant difference.

2 and 3, the grain structure ratio of the blank used in the novel forging process of the present application can be seen. The grain structure of the existing casting process is much finer and more uniform; as can be seen from Table 1, the mechanical properties of the novel process of the present application are significantly higher than those of the prior art; as can be seen from Fig. 5 and Fig. 6, After the enhanced corrosion test, the product samples of the novel process of the present application still retain a certain metallic luster, and the product samples of the current process have partially lost the metallic luster. Therefore, the Na2S corrosion resistance of the new process product is much better than the current process. .

In summary, the present application provides a novel production process for a forged artificial joint and a metal product. The present application does not directly manufacture a forged blank by a conventional process such as casting, rolling, and drawing of a steel ingot, but directly adopts Fine grain casting manufactures forged blanks for forging production. The grain size of forged blanks produced by this method is much smaller than that of general cast blanks; the uniformity of grain size can be said to be completely uniform, and the grain size is uniform throughout the casting section. The size is almost the same; and the casting process is impossible to concentrate the shrinkage hole at all, because the deep subcooled fine-grain casting is crystallization at the same time on the entire casting section, so the solidification shrinkage is diffuse; Forging artificial joints for casting blank production have high strength and good wear resistance, and compared with similar products, less raw material consumption, less energy consumption, high product qualification rate; all metal-type medical implants except artificial joints Can learn from this new production process; and other non-medical implants forging metal products, mechanical parts, etc. We can learn from this new production process.

The above description is only a preferred embodiment of the present application, but the scope of protection of the present application is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed in the present application. Replacement should be covered by the scope of this application.

Claims (10)

The invention relates to a novel production process for forging artificial joints and metal products, which is characterized in that the forged blanks are directly produced by fine-grain casting for forging production, and the following steps are specifically included: Step 1. Casting a fine crystal blank for forging using a deep subcooled fine grain casting furnace; Step 2. Cutting and grinding the whole set of fine crystal blanks to obtain a fine crystal forged blank, and then cleaning the obtained fine crystal forged blanks; Step 3. The fine crystal forged blank obtained in the step 2 is placed in a heat treatment furnace for heating; Step 4. The fine-grained forging blank heated in step 3 is placed in a forging die for forging; Step 5. Take the forged product from the forging die and trim and polish it to obtain the finished product. A novel production process for a forged artificial joint and a metal product according to claim 1, wherein in the step 1, the deep subcooled fine crystal casting furnace mainly comprises: melting enthalpy, casting, and stabilizing a constant magnetic field magnetic pole, a mold carrying turntable, the melting crucible being located above the mold, the constant magnetic field magnetic pole being located around the mold, the mold carrying turntable being located at a lower end of the mold, and Fixedly connected to the mold; the melting crucible is provided with an alternating current induction coil and a DC electric constant magnetic field; the melting crucible, the constant magnetic field magnetic pole, and the mold carrying turntable are located in the casting furnace, and the casting mold passes The equipment is placed from the outside of the furnace door onto the mold carrying carousel. A novel production process for a forged artificial joint and a metal product according to claim 2, wherein the constant magnetic field magnetic pole is divided into a constant magnetic field N pole and a steady magnetic field S pole, the stable magnetic field The N pole and the stable magnetic field S are oppositely placed, and the mold is located between the constant magnetic field N pole and the steady magnetic field S pole. A novel production process for a forged artificial joint and a metal product according to claim 3, wherein the mold carrying turntable is rotated slowly outside the furnace by manual or electric means, and the casting bearing The loading carousel is input by a slow rotating shaft having a diameter of not less than 25 mm and not more than 65 mm, and the mold carrying carousel is rotated by a ratchet. A novel production process for a forged artificial joint and metal product according to claim 1 or 4, wherein in the step 2, the processing of the cast blank is sand cleaning, cutting, grinding and polishing. A novel production process for a forged artificial joint and a metal product according to claim 5, wherein in the step 3, the heating temperature of the heat treatment furnace ranges from 900 ° C to 1200 ° C. A novel production process for a forged artificial joint and a metal product according to claim 1 or 6, wherein in the step 4, the forged blank is swaged using a 2 to 5 ton forging hammer. A novel production process for a forged artificial joint and a metal product according to claim 7, wherein the novel production process can be applied to artificial joints, all metal-type medical implants other than artificial joints, and Forging metal products and mechanical parts for non-medical implants. Use of a product prepared by a novel production process for forged artificial joints and metal articles according to claims 1-8, characterized in that the prepared forged blanks are used for forging medical implants. The use of a product prepared by a novel production process of a forged artificial joint and a metal product according to claim 9, wherein the artificial joint forged by the production process of the present application is directly used for clinical use.

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