JPH0730365B2 - Method for manufacturing member having porous layer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a metal member having a desired porous layer, and particularly to a porous layer having a complicated shape and firmly fixed. The present invention relates to a method for manufacturing a metal member.

[Prior Art] Conventionally, for implant bodies (Co-Cr alloys) with complicated shapes,
There is a method of manufacturing a metal member having a porous layer by sintering powder (beads) of the same alloy material to form a porous layer.
There are drawbacks such as the coarsening of crystal grains during sintering of the alloy, which reduces fatigue strength, and the inferior biocompatibility compared to titanium alloys. There is also a method for producing a fixed porous biomaterial by diffusing and bonding a pad-shaped object formed by pressing and compacting a pure titanium fine wire to a Ti-6Al-4V alloy implant body. The strength is weak, and if a thin wire made of Ti-6Al-4V is used to secure the strength, there is a disadvantage in that it is very difficult to process the thin wire. Also, Ti-6Al-4V
There is also a manufacturing method in which the alloy powder of 1 is fixed to the implant body of the same metal material by sintering at normal pressure. However, since this sintering temperature must be as high as 1200 to 1400 ° C, the implant body has coarse crystal grains. However, there is a disadvantage in that it causes deterioration of the material such as needle-like structure and enlargement of grain boundary phase. Further, there is a disadvantage in that the bonding strength is limited in the atmospheric pressure sintering process, and it is difficult to firmly fix the powder having a large particle size.

Since the β-transus temperature of titanium alloys, that is, the temperature at which the β single-phase region is reached, when Ti-6Al-4V alloy is heated to a temperature of around 1000 ° C or more, the crystal grains become coarse and have an acicular structure. Although the ductility decreases, heating to a temperature below the β-transus temperature does not substantially reduce the material and strength. It is very difficult to produce an implant material with a complicated shape or an implant material with a complicated porous layer, and we have not found a product that has been put into practical use. The only product actually used is a simple one. Is.

[Problems to be Solved by the Invention] It is an object of the present invention to provide a method in which a porous layer is firmly adhered to the surface of a metal member having a complicated shape, and the formed one can be easily manufactured. In addition, the present invention provides a porous bone (porous coating) on the surface of an implant main body having a complicated shape, and utilizes the growth of bone tissue from the living bone to utilize living bone without using conventional bone cement. In order to form a porous biomaterial that can be firmly bonded to the implant material, the powder of any particle size can be bonded firmly at a relatively low temperature, and can be formed into a three-dimensional shape such as a curved surface or a polyhedral surface. It is an object of the present invention to provide a manufacturing method in which fixing coating is performed at the same time.

[Means for Solving Problems] In order to manufacture a member having a porous layer having a relatively complicated shape as described above, the present invention provides a desired powder metal on the surface of a metal member having a predetermined shape. After forming a powdered metal layer made of a material, through a thin-walled capsule capped on the powdered metal layer, heating while applying a high-pressure gas to produce a coated metal member, The capsule is a superplastic material metal material, which is a metal material that can be easily chemically removed. A predetermined space in the capsule is filled with the powder metal material, and the inside of the capsule is evacuated to form a metal member. In a temperature range in which material deterioration does not occur, and in which the metal capsule exhibits a superplasticity phenomenon sufficiently, that is, in a temperature range of 600 ° C or higher and a transus temperature of the metal material or lower, the capsule is isotropically hot. Pressure of 1MPa to 20MPa By applying pressure, a porous layer made of the powder metal material is firmly fixed and formed on the surface of the metal member having the predetermined shape, and then chemically fixed to the porous layer by chemical milling. The capsule is removed, and the formed porous layer is machined into an arbitrary shape to produce a coated metal member having a porous layer adhered to the surface of the metal member with an appropriate adhesion force. It is a method of manufacturing the coated metal member. The metal member is preferably for in-vivo replacement or prosthesis. Further, the metal member and the powder metal material are preferably titanium or titanium alloy, that is, Ti-6Al-4V alloy.

[Structure of the Invention] In the metal member having the porous layer according to the present invention, the implant main body metal member formed according to the use of the predetermined shape is placed in the metal capsule for HIP treatment of the predetermined shape, and the metal capsule The metal powder material is filled in a predetermined space corresponding to the surface of the implant body in which the porous layer in which is to be formed, and then the inside of the metal capsule is evacuated,
It is hermetically sealed, HIP-treated and isotropically hot pressed in a temperature range that does not cause deterioration of the sealed metallic material. Next, the implant body having a porous layer made of metal powder that is fixedly formed together with the capsule by the HIP treatment is machined or chemically milled to remove the metal capsule to obtain a product. Alternatively, in order to make the obtained metal member having the porous layer into an arbitrary shape, the firmly formed porous layer is machined to obtain a product.

The method of the present invention provides a metal member suitable for artificial bone. That is, a titanium alloy is used as an implant material for a metal member, a porous layer is provided on the surface thereof, and a member convenient for bonding the bone and the implant material by bone tissue growth from living bone can be provided. . According to the invention, a porous layer for this can be formed at a relatively low temperature,
Moreover, it provides a material firmly fixed to the implant material. That is, in the ordinary atmospheric pressure sintering method, a high temperature of about 1300 ° C. is required to sinter and fix the porous layer, whereas in the manufacturing method according to the present invention, there is no deterioration of the material.
It can firmly adhere and form the porous layer at temperatures below about 00 ℃.

According to such a manufacturing method, bonding can be performed much more strongly than in the pressureless sintering method, so that the risk of peeling of the porous layer due to the load when implanting the manufactured artificial bone is reduced, and further, Since it is not necessary to heat to a high temperature so that the material deteriorates, strength, especially fatigue strength, has been significantly improved compared to normal pressure sintering, and it has become possible to coat complex shapes that were previously impossible. .

According to the manufacturing method of the present invention, the sealed capsule is heated below the transus temperature of the titanium alloy to, for example, about 600 to 950 ° C., and is subjected to HIP treatment under pressure. This pressure is 0.1 ~
Perform at an appropriate pressure in the range of 2.0 kgf / mm ² . The time of holding at high temperature and high pressure may be arbitrary, but 0.3 to 3 hours is preferable.
Further, the vacuum encapsulation process is preferably performed by using a method of closing the degassing port after vacuum deaeration, or by using electron beam welding when a material capable of electron beam welding is used.

When the HIP process is performed in this way, a porous layer to be formed can be formed on the surface of a metal member having a predetermined shape including a complicated shape having a curved surface, a multi-sided surface, etc., in accordance with the shape.

Next, the capsule metal member powder component thus formed is subjected to machining or chemical milling to remove the capsule and further to machine the porous layer adhered and formed in an arbitrary shape. Thus, a member having a porous layer of any shape can be obtained. In this case, when burrs are generated by machining and a sound porous layer cannot be obtained, the surface is ground and polished to remove the burrs, or the burrs are removed by chemical milling.

As described above, the manufacturing method according to the present invention can provide a porous layer at a time on any surface of the implant material by utilizing the HIP treatment, and can mechanically remove the capsule to obtain a product, Further, it is possible to reduce the cost by processing a large amount at a time.

The artificial bone fixation method, ie, the cementless method, in which a porous layer is fixed on the surface of the implant material manufactured by the present invention by utilizing the bone penetration into the porous layer, that is, the cementless method is a problem of loosening due to the bone cement method. , The cementless method is considered to be the mainstream of the artificial bone fixation method because it is very effective as a means for avoiding the problem of adverse effects of the monomer on the human body. In addition, Co-Cr alloys are now widely used, but recently
Ti-6Al-4V alloy is considered to be the most suitable implant material from the viewpoint of biocompatibility, that is, biocompatibility, specific strength, that is, lightness and strength, and corrosion resistance in vivo, and this material will be widely used in the future. I think that the. At present, a titanium alloy implant material provided with a porous layer of a titanium alloy powder sintered body and having an appropriate porous fixing strength has not been put into practical use. This is considered to be because there is no method for firmly adhering the porous layer to the implant body without lowering the material as described above. When used for artificial bones, it is said that a porous layer having a pore size of 100 to 300 μm is suitable for fixation by invasion of bone tissue, but if the pore size is to be obtained with powder, it is considerably large particles. It was necessary to use powder with a diameter, and if the powder with that diameter was joined by pressureless sintering, proper joining strength could not be obtained.

[Operation] In the manufacturing method of the present invention, a capsule filled with metal powder is vacuum-sealed on a predetermined surface of an implant material having a predetermined shape, and HIP (hot isostatic pressing, Hot Isostatic Pressin) is performed.
g) Isotropic pressure is applied by the treatment, and the porous layer is fixedly formed on the prescribed surface of the implant body.

If the metal material used for the porous layer is kept in a temperature range where it does not deteriorate and stress is applied to form a porous layer, there is no coarsening of crystal grains or formation of needle-like structures, and there is an appropriate pore size.
A porous layer adhered with an appropriate bonding strength can be obtained.

Next, a method for manufacturing a member having a porous layer according to the present invention will be described with reference to its specific example.

[Example] A case where a porous layer is formed on a cylindrical implant body 4 (titanium alloy) as shown in the figure will be described. First, the implant body 4 is inserted into the metal capsule 1. And the implant body 4 and the capsule 1
The metal powder 3 is filled in the space, where the porous layer is to be formed, and the lid 2 is attached to the open end. After degassing the metal-filled capsule to a vacuum, the shield portion 5 at the end thereof was sealed with an electron beam or the like.

The sealed capsule was heated to about 800 to 950 ° C and pressure was applied to the HIP process.

The applied pressure was 0.3 to 0.5 kgf / mm ² . Hold time is about 1
Done in time.

Next, the capsule, the sintered powder, and the implant body thus obtained were combined by chemical milling to remove the capsule, or the product was machined into a desired shape. Further, when burrs were generated by this machining, the burrs were removed by grinding and polishing the surface to remove burrs or by performing chemical milling.

As described above, the method for forming the porous layer on the implant body of the present invention is performed by using artificial bones including artificial tooth roots in general, forming a surface layer structure on the surface of the socket that contacts the living bone, and fixing along the bone. It is used in the manufacture of all artificial members for living body that work effectively by combining living bone with bone tissue growth such as formation of surface layer structure of bone prosthesis material and bone defect reconstruction material.

[Advantages of the Invention] The following remarkable technical advantages were obtained by the method for producing a member having a porous layer according to the present invention. First, since the porous layer is bonded at a temperature without material deterioration, the problems of crystal grain coarsening and acicular structure are solved, and a porous layer that does not deteriorate in material and strength due to the porous layer bonding is formed. Provided is a method of manufacturing a metal member having. Secondly, in order to bond the porous layers by applying an appropriate pressure, a metal member having an appropriate pore size and having a bonded porous layer with an appropriate bonding strength is provided. Thirdly, since the HIP process is used, a manufacturing method capable of forming a porous layer at a time on a surface having an arbitrarily complicated shape is provided, and a method capable of processing and manufacturing a large amount of products at a time. Was provided. Fourth, there is a method for easily manufacturing a product having a complicated porous layer shape at low cost by performing machining after the porous layer is fixedly formed on the implant main body. sponsored. Therefore, it is an object of the present invention to provide a method capable of inexpensively mass-producing an implant material having a highly reliable porous layer having a complicated shape by the manufacturing method of the present invention.

[Brief description of drawings]

FIG. 1 is a sectional view sequentially showing a method for manufacturing a metal member having a porous layer according to the manufacturing method of the present invention. [Description of symbols of main parts] 1 ... Metal capsule 3 ... Metal powder 4 ... Implant body

Claims (4)

[Claims] 1. A powder metal layer made of a desired powder metal material is formed on the surface of a metal member having a predetermined shape, and a high-pressure gas is made to act through a thin capsule capped on the powder metal layer. While heating, in the method for producing the coated metal member; the thin-walled capsule is a superplastic material metal material and a metal material that can be easily chemically removed, and Powder metal material is filled, the inside of the capsule is evacuated to a vacuum, the temperature range in which the material deterioration of the metal member does not occur, and the temperature range in which the metal capsule shows a superplastic phenomenon sufficiently, that is, 600 ° C. or higher, Heat to a temperature range below the Transus temperature and heat the capsule isotropically to 1M.
By pressurizing under a pressure of Pa to 20 MPa, a porous layer of the powder metal material is firmly adhered and formed on the surface of the metal member having the predetermined shape, and then the porous layer is chemically chemically milled. To remove the capsules adhered to, and machine the formed porous layer into an arbitrary shape to produce a coated metal member having a porous layer adhered to the surface of the metal member with an appropriate adhesion force. A method for manufacturing the coated metal member, comprising: 2. The method for producing a coated metal member according to claim 1, wherein the metal member is for in-vivo replacement or prosthesis. 3. The method for producing a coated metal member according to claim 1, wherein the metal member and the powder metal material are titanium or a titanium alloy. 4. The metal member and powder metal material are Ti-6Al-4.
The method for producing a coated metal member according to claim 1, which is a V alloy.