JP3871071B2 - Fabrication method of fiber reinforced metal products - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a metal product reinforced with fibers.
[0002]
[Prior art]
Currently, fiber reinforced metal matrix composites (FRM) in which fibers are artificially imparted to metals are attracting attention. As the fiber, carbon fiber, silicon carbide fiber SiC or the like is used, and the strength does not decrease even when the temperature exceeds 1000 ° C. In the case of the FRM intended for weight reduction as the matrix metal, aluminum Al and magnesium Mg are mainly used. Titanium Ti is used for those requiring higher heat resistance. In the case of Ti-based FRM, the heat-resistant temperature is about 400 ° C., although it depends on the heat-resistant temperature of the base material Ti-based alloy. As described above, FRM is excellent in strength, heat resistance, and the like, and researches are being conducted for use in jet engines, moving blades of gas turbines, and the like.
[0003]
FIG. 2 is a flowchart for producing a moving blade of a jet engine by FRM. Titanium Ti foil and silicon carbide SiC fiber are used as materials. Ti foil and SiC fiber are cut into a shape that makes it easy to form a wing shape. Next, after laminating them alternately, they are pressed by a vacuum hot press method. In this case, the hot pressing method is a method in which a mixture of metal foil and fiber is inserted into a graphite and ceramic mold and pressed from above and below to diffuse and fuse the metal foils together. After that, creep deformation is performed to form a moving blade, and after attaching a moving blade base, machining and chemical milling (chemical finishing) are performed to complete the moving blade.
[0004]
[Problems to be solved by the invention]
In the above manufacturing method, the shape of the wing is formed by creep deformation. However, since the fiber is an elastic body, the twist is returned and it is difficult to obtain an accurate wing shape. Moreover, since the joint part of the wing | blade and pedestal which needs the strongest and reliability is joined, there exists a possibility of leaving | separating. In addition, the fiber has high strength but is brittle with respect to impact load. Foreign matter may collide with a moving blade such as a jet engine or a gas turbine, and impact resistance is required.
[0005]
The present invention has been made in view of the above-mentioned problems, and can provide a method for manufacturing an FRM product that can be machined with high accuracy, the wing and the pedestal are integrally formed, and has excellent impact resistance. The purpose is to do.
[0006]
[Means for Solving the Problems]
To achieve the above object, in the invention of claim 1, alternating with metal block having between a small than fabricated object empty, creating a metal lid covering the space, a metal foil and a fiber into the space After being laminated and covered with the lid, they are fused by the HIP method, and are cut into the shape of the object to be manufactured with the metal block and the metal of the lid left around by machining.
[0007]
In invention of Claim 1, metal foil and a fiber are laminated | stacked alternately in a metal block, and FRM is formed. Since the machining is done only up to the metal block and lid, the end of the fiber is not exposed. For this reason, since machining is performed only on metal, cutting is easy and processing can be performed with high accuracy. Further, fibers that are brittle to impact are not exposed, and the impact is absorbed by the metal that wraps the fibers and the metal foil, so the impact resistance is improved.
[0008]
According to a second aspect of the present invention, after the machining, hot pressing is further performed using a mold of an object to be manufactured.
[0009]
In the second aspect of the present invention, when the distortion is released after the machining in the first aspect of the invention and a slight deformation occurs, the manufacturing object is placed in the mold and hot pressed to accurately match the mold. Can be manufactured in any shape. In this case, since the deformation is small, the shape can be corrected by creep.
[0010]
According to a third aspect of the present invention, the object to be manufactured is a moving blade, the metal block, the lid, and the metal foil are made of titanium, and the fiber is silicon carbide.
[0011]
In the invention of claim 3, the manufacturing object is a moving blade, Ti foils and SiC fibers are alternately laminated, and the metal block and the lid are made of Ti, so that it has excellent heat resistance and impact resistance and has an accurate shape. Can be obtained.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a flow chart for manufacturing a moving blade according to the present embodiment. The object to be manufactured is a moving blade of a jet engine or a gas turbine that requires heat resistance, impact resistance, and large specific strength. Rotor blades are required to have high heat resistance and impact resistance due to the impact of foreign objects in the air, and the specific strength (strength per unit area divided by unit weight) must be increased to reduce weight. is there. For this reason, Ti foil and SiC fiber are used, and the metal block and its lid are made of Ti.
[0013]
In FIG. 1, a Ti block 1 is formed in the metal block forming step. The Ti block 1 has a rough shape of a moving blade and engraves a space 2 smaller than the moving blade . Next, in the lid forming step, a Ti lid 3 that covers this space 2 and matches the shape of the upper surface of the Ti block 1 is formed. The lid 3 has a thickness of about 4 mm in consideration of the machining allowance. In the cutting step, the SiC fiber 4 and the Ti foil 5 are cut into a shape that matches the shape of the space 2 and the moving blade. In the laminating step, SiC fibers 4 and Ti foils 5 are alternately laminated in the space 2 and then the lid 3 is welded to the Ti block 1 by an electron beam.
[0014]
Next, in the HIP process, the Ti block 1, the lid 3, the SiC fiber 4, and the Ti foil 5 are integrally fused in a high-temperature and high-pressure gas atmosphere. The HIP method is a hot isostatic pressing method. In this case, a metal foil, fiber, etc. mixture is encapsulated in a capsule of metal, quartz glass, etc. and bonded in advance, and the metal foil in a high-temperature and high-pressure gas atmosphere. It is a method to diffuse and fuse together. Cutting into the shape of a moving blade in the machining process. Cutting is performed in the range of the Ti block 1 and the lid 3, and the SiC fiber 4 and the Ti foil 5 are not cut. For this reason, since the titanium metal portion is cut, it can be cut into an accurate shape. When the thickness of the moving blade is thin, the distortion at the time of fusion may be released by machining to be deformed. In such a case, a moving blade mold 6 is prepared and a final forming step by hot pressing is provided. Since this final forming process is a case where it is deformed by machining, it is not always a necessary process. The surface is finished by chemical milling as the final finishing process. A predetermined level of blade is obtained by inspection.
[0015]
In the embodiments, the description has been given by taking the moving blade as an example, but the present invention is not limited to the moving blade, and can be applied to manufacture of a product using a composite material of FRM. Moreover, although the case where titanium was used for metal foil, a block, and a lid | cover and the silicon carbide was used for the fiber was demonstrated, these should just change suitably according to the use of a product. In addition, although the metal block, the lid, and the metal foil are the same type of metal, they need not be the same type.
[0016]
【The invention's effect】
As is clear from the above description, in the present invention, the metal foil and the fiber are alternately arranged to constitute the FRM, and the laminated portion of the metal foil and the fiber is wrapped with metal, and machining is performed on the wrapped metal part. Therefore, it is easy to process and can be cut into an accurate shape. Further, the product manufactured according to the present invention is excellent in impact resistance because the laminated portion that is weak against impact load is not exposed and is covered with a metal that is strong against impact load.
[Brief description of the drawings]
FIG. 1 is a flowchart of manufacturing an FRM blade according to an embodiment.
FIG. 2 is a flowchart of manufacturing an FRM blade by a conventional creep deformation method.
[Explanation of symbols]
1 Ti block 2 Space 4 SiC fiber 5 Ti foil 6 Mold

Claims (3)

Create a metal block having between a small than fabricated object empty, the metal lid that covers the space,
After alternately laminating metal foil and fibers in the space, covering with the lid, and fusing by HIP method,
A method for producing a fiber-reinforced metal product, characterized in that the metal block and its lid metal are cut by machining to a shape of a production object.   2. The method for producing a fiber reinforced metal product according to claim 1, further comprising hot pressing using a mold of an object to be produced after the machining.   3. The fiber-reinforced metal product manufacture according to claim 1, wherein the object to be manufactured is a moving blade, the metal block, the lid, and the metal foil are made of titanium, and the fiber is silicon carbide. Method.

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