JP4089460B2 - Method for producing metal matrix composite member - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a metal matrix composite member.
[0002]
[Prior art]
In recent years, metal-based composite materials having characteristics such as light weight and high strength, in which a base metal such as an aluminum alloy and a reinforcing material such as ceramic fibers and particles are combined, are widely used. As a method for producing this metal matrix composite material, conventionally, when a porous preform containing a reinforcing material is impregnated with a molten metal, a metal mold for a closed mold is used to improve the permeability of the molten metal. It is known that a preform is placed in a container, the mold container is sealed, and evacuation is performed through a filter (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
JP 09-287036 A (page 3)
[0004]
[Problems to be solved by the invention]
By the way, in the manufacturing method of the metal matrix composite material disclosed in Patent Document 1, a preform material such as a reinforcing material and a binder and a dispersion medium are mixed in the slurry container, and the dispersion medium is mixed in the slurry container through a filter. The preform is formed by sucking and removing. The formed preform is taken out from the slurry container described above according to the drying / firing process before the molten metal impregnation process.
[0005]
In such a method for producing a metal matrix composite material, since the preform is moved between separate containers, it has been necessary to handle the preform in a state of poor solidity with sufficient care. However, in some cases, the shape of the preform cannot be ensured, and it may be necessary to exclude it as a defective product before the molten metal impregnation step. For this reason, conventionally, in order to ensure the safety of the preform, it has been desired to realize better handling properties.
[0006]
This invention is made | formed in view of the said technical subject, and it aims at providing the manufacturing method of the metal group composite member excellent in the handleability of preform.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 of the present application is the method for producing a metal matrix composite member obtained by impregnating a base metal with a porous preform composed of a preform material containing a reinforcing material. The dispersion medium in the dispersed slurry is sucked and removed from the slurry container through the filter, the preform molded on the filter by suction removal is taken out from the slurry container together with the filter, and the preform is removed from the filter. The preform is set in a mold container through the filter, and a side of the filter facing the preform is poured into the mold container while the molten metal is poured into the mold container. The inside of the mold container is depressurized from the opposite side, and the preform is impregnated with a molten metal of the base metal.
[0009]
The invention according to claim 2 of the present application is the invention according to claim 1 , wherein the filter is made of metal.
[0010]
Further, the invention according to claim 3 of the present application is the invention according to claim 1, wherein the filter is set at a state where the wettability of the base metal to the molten metal is low at least on the side facing the preform. It is characterized by being.
[0011]
Still, the invention according to claim 4 of the present application is the invention according to claim 3, provided with a step of firing after drying the preform, the filter is oxidized during the firing process of the preform It is made of a possible material, and an oxidation layer is generated on the pore surface of the filter by its oxidation.
[0012]
Furthermore, the invention according to claim 5 of the present application is characterized in that, in the invention according to claim 3 , the filter is formed of graphite particles.
[0013]
Furthermore, the invention according to claim 6 of the present application is characterized in that, in the invention according to claim 3 , a coating film is formed on the side of the filter facing the preform before the preform is suction-molded. It is what.
[0014]
Furthermore, the invention according to claim 7 of the present application is the invention according to claim 3 , wherein the dispersion medium in the slurry in which the graphite particles are dispersed is passed through the filter before the preform is suction-molded. The filter is sucked and removed from the container and impregnated with graphite particles on the side of the filter facing the preform.
[0015]
Furthermore, in the invention according to claim 8 of the present application, in any one of the inventions according to claims 1 to 7 , the filter is formed so as to have a volume ratio larger than the volume ratio of the preform. It is characterized by that.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
In the method for producing a metal matrix composite member of the present invention, first, a preform (hereinafter referred to as a preform) made of a preform material including a reinforcing material is suction-molded. (A) of FIG. 1 is explanatory drawing showing the suction molding process of a preform. In this suction molding step, the porous filter 10 is set in the slurry container 2 provided with the exhaust pressure reducing hole 2a on the bottom surface, and then the reinforcing material 3 and the binder 4 as a binding material for binding the reinforcing material 3, and The dispersion medium 5 is mixed in the slurry container 2. Thereafter, the slurry (suspension) 6 in which the reinforcing material 3 and the binder 4 are dispersed is sucked through the filter 10, the dispersion medium 5 is sucked and removed, and the preform 7 drained on the filter 10 is formed. .
[0017]
In Embodiment 1, alumina short fibers (trade name: Safil RG Mild) manufactured by ICI (ICI Chemicals & Polymers Ltd) are used as the reinforcing material 3, and silica sol (trade name: Snow manufactured by Nissan Chemical Co., Ltd.) is used as the binder 4. Tex 30) was used, and water was used as the dispersion medium 5. Further, as the filter 10, a ceramic board made of alumina / silica fiber having a diameter of 90 mm, a thickness of 6 mm, and a volume ratio of about 10% was used.
[0018]
After the preform 7 is formed by suction, the preform 7 is dried and baked to solidify the preform 7 after liquid removal. FIG. 1B is an explanatory view showing the drying and firing steps of the preform 7. In this drying and firing process, the preform 7 molded in the slurry container 2 is taken out of the slurry container 2 together with the filter 10 and placed on the filter 10 in the drying and firing furnace 9. set.
[0019]
In the first embodiment, the preform 7 was dried at room temperature for 12 hours and then baked at 800 ° C. for 1 hour. While adopting the preform raw material described above, the preform 7 having a diameter of 90 mm, a thickness of 5 mm, and a volume ratio of about 30% was obtained by performing the drying and firing processes.
In addition, a baking process is implemented as needed and does not need to be implemented especially if the solidity more than predetermined is ensured about the preform 7 after drying.
[0020]
After the preform 7 is dried and baked, the preform 7 is impregnated with a base metal melt. (C) of FIG. 1 is explanatory drawing showing the impregnation process. In this impregnation step, the preform 7 and the filter 10 after drying and firing are set in a mold container 12 having an exhaust pressure reducing hole 12a on the bottom surface, and then a molten metal 14 is poured. At the same time, air pressure is applied to the molten metal from above the mold container 12, and the pressure in the mold container 12 is reduced through the exhaust pressure reducing hole 12a using a vacuum pump (not shown). Thereby, the preform 7 is impregnated with the melt of the base metal 14, and the preform 7 and the base metal 14 are combined. As a result, a metal matrix composite member is obtained.
[0021]
In the first embodiment, an AC8A alloy (JIS H5202) is used as a base metal. Further, the temperature of the molten metal 14 was set to 750 ° C., and the preheating temperature of the preform 7 was set to 600 ° C. Further, the air pressure applied to the molten metal from above the mold container 12 was set to 4 kgf / cm ² (≈0.392 MPa).
[0022]
In this impregnation step, when the preform 7 and the filter 10 are set in the metal container 12, the filter 10 is preferably adhered to the bottom surface in the mold container 12. As a result, the filter 10 is cooled through the mold container 12, so that the solidification of the molten metal of the base metal 14 that passes through the filter 10 is promoted, and the molten metal intrusion into the filter 10 and the exhaust pressure reducing hole 12 a is prevented. Can do. This effect becomes even greater when the bottom of the mold container 12 (the surface in contact with the filter 10) is cooled.
[0023]
As described above, in this method for manufacturing a metal matrix composite member, the steps after the suction molding of the preform 7 are performed by the combination of the preform 7 and the filter 10, so that the preform 7 is placed on the filter 10. It can be handled in a supported state. Thereby, the handleability of the preform 7 in a series of steps for producing the metal matrix composite member as shown in FIGS. 1A to 1C can be improved.
Further, in this method of manufacturing a metal matrix composite member, a filter set in the slurry container 2 during the suction molding process of the preform 7 and a mold container 12 inside the preform 7 with the base metal melt being impregnated. It is possible to share the filter to be set to the same, and as a result, the economics of the manufacturing method can be improved.
[0024]
Hereinafter, another embodiment of the present invention will be described. In the embodiments described below, the same raw materials and processes as those in the first embodiment are employed unless otherwise specified.
Embodiment 2. FIG.
In the first embodiment described above, a ceramic board made of alumina / silica fibers is used as the filter 10. However, the present invention is not limited to this, and a filter made of another material may be used as appropriate. In the second embodiment, as the filter 10, an aluminum shot having # 46 and an average diameter of about 0.4 mm is molded with an organic binder made of a phenol resin is used. Here, the volume ratio of the filter 10 is set to about 60% larger than that of the preform 7 in order to suppress the insertion of the molten metal 14 into the filter 10 during the impregnation step. In this case, considering the heat resistance of the filter 10, the firing temperature was set to 150 ° C. in the firing step.
[0025]
By using such a filter 10, when the molten metal 14 is inserted into the filter 10 through the preform 7 during the impregnation step, the material of the filter 10 is the same aluminum as the base metal 14. When the unnecessary filter and insertion portion are removed by cutting after the process, the machinability is good, and they can be easily removed.
[0026]
In this regard, FIG. 2 schematically shows an insertion portion 14a of the base metal 14 with respect to the filter 10 and an unnecessary filter and insertion portion (that is, a portion that can be removed by cutting) R. As shown in this figure, in the impregnation step, the molten metal 14 may pass through the metal matrix composite member 20 and be inserted into the filter 10 from its upper surface. The insertion part of the base metal is represented by reference numeral 14a. However, in the second embodiment, since the filter 10 is made of the same material as the base metal 14, the filter 10 and the insertion portion 14a of the base metal 14 inserted therein are made of the same material. As a result, the machinability is good when cutting and removing the cutting removal portion R after the impregnation step, and they can be easily removed. That is, when the filter 10 made of the same material as the base metal 14 is used, the filter 10 and the base metal 14 are different from each other after the impregnation step in the first embodiment. Machining can be easily performed.
[0027]
Moreover, the same effect was acquired also when using what formed the aluminum fiber by the organic binder instead of the filter 10 shape | molded by the aluminum shot. Furthermore, when using a compression-molded aluminum alloy cutting powder, it can be formed as a filter 10 without using an organic binder, so that it is excellent in economic efficiency and the firing temperature in the firing step is increased. The temperature could rise to about 500 ° C.
[0028]
In addition, it is possible to use other inexpensive metal shots (for example, zinc, steel, etc.) instead of aluminum shots. In this case, different types of filters and insertion parts are removed after the impregnation process. Since the metal is co-processed, its machinability is inferior to that of using an aluminum filter, but is superior to the case of the first embodiment described above (when a ceramic filter is used). was gotten.
[0029]
Here, an example of using a filter 10 made of the same or different kind of metal as the base metal has been given, but is not particularly limited to metal, and if it is made of a material that is easy to machine, Even when the molten metal 14 is inserted up to the filter 10 during the impregnation step, unnecessary filters and insertion portions can be cut and removed relatively easily.
[0030]
Embodiment 3 FIG.
In the third embodiment, an iron-based porous body made of SUS316 and having a volume ratio of about 60% is used as the filter 10. And the filter 10 which supports the preform 7 was oxidized at the time of the baking process of the preform 7, and the oxidation layer was produced | generated on the pore surface. In the firing step, the firing temperature was set to 800 ° C.
[0031]
When the filter 10 includes the oxide layer, the wettability on the surface thereof is lowered. As a result, the insertion of the molten metal 14 into the filter 10 during the impregnation process was suppressed. In the specification of the present application, “wetting” refers to a characteristic that is determined by the size of a contact angle of a droplet with respect to a contact surface of a solid when the liquid and the solid come into contact with each other. It can be said that the larger the contact angle, the lower the wettability.
[0032]
As described above, the filter 10 is made of a material that can be oxidized during the firing step of the preform 7, and an oxide layer is generated on the surface of the pores, so that the base metal 14 melts into the filter 10 in the impregnation step. Insertion can be suppressed. As a result, it is possible to facilitate machining for removing unnecessary filters and insertion portions after the impregnation step.
[0033]
Embodiment 4 FIG.
In the fourth embodiment, the filter 10 is made of graphite particles. At the time of molding, the volume ratio of the filter 10 after the drying and firing process is larger than the volume ratio of the preform 7 made of short alumina fibers in order to suppress the insertion of the base metal melt into the filter 10 during the impregnation process. About 60%. In the firing step, the firing temperature was set to 800 ° C., and firing was performed in a non-oxidizing atmosphere in order to prevent oxidative wear of graphite forming the filter 10.
[0034]
When such a filter 10 is used, the wettability of the molten metal (aluminum molten metal) of the base metal 14 with respect to graphite is low, and the volume ratio of the filter 10 is larger than that of the preform 7. Insertion of the molten metal 14 into the filter 10 was suppressed. As a result, it was possible to facilitate machining for cutting and removing unnecessary filters and insertion portions after the impregnation step.
[0035]
The particles to be formed by the filter 10 are not particularly limited to graphite particles. For example, if particles having low wettability with respect to the molten metal, such as titania particles and boron nitride particles, are used, the same effect can be obtained.
[0036]
Embodiment 5. FIG.
In the fifth embodiment, before the preform 7 is suction-molded, the filter 10 is coated on the side facing the preform 7. Here, a coating agent made of zinc oxide was used. FIG. 3 shows a filter 10 having a coating film 22 on its upper surface and a preform 7 molded on the filter 10.
[0037]
Thus, although the time required for the suction molding of the preform 7 is extended by coating the filter 10 on the side facing the preform 7, the wettability of the filter surface with respect to the molten metal 14 is lowered. . Thereby, the molten metal insertion to the filter 10 at the time of an impregnation process was fully suppressed.
[0038]
Embodiment 6 FIG.
FIGS. 4 (a) and 4 (b) are both diagrams according to Embodiment 6 of the present invention, and before the suction molding step of the preform 7, the slurry from which graphite particles are dispersed is passed through the filter 10 respectively. FIG. 5 is an explanatory diagram showing a step of sucking and removing the dispersion medium, and an explanatory diagram showing a preform suction molding step following the step shown in FIG.
In the sixth embodiment, as well understood from FIG. 4A, before the preform 7 is formed by suction, that is, before the slurry 6 in which the preform material including the reinforcing material is dispersed, The slurry 31 in which the graphite particles were dispersed was placed in the slurry container 2, and the dispersion medium in the slurry 31 was removed by suction, and the side of the filter 10 facing the preform 7 was impregnated with the graphite particles. Reference numeral 31 a represents an impregnated portion of the filter 10 with the graphite particles.
[0039]
Thereafter, as shown in FIG. 4B, the slurry 6 in which the preform material including the reinforcing material and the binder is dispersed is placed in the slurry container 2, and the dispersion medium in the slurry 6 is removed by suction to obtain the preform 7. (Not shown in FIG. 4) was molded.
[0040]
Since the filter 10 includes the impregnated portion 31a of the graphite particles on the side facing the preform 7, the wettability on the surface thereof is lowered. As a result, the insertion of the molten metal 14 into the filter 10 during the impregnation process was suppressed.
[0041]
Note that the present invention is not limited to the illustrated embodiments, and it goes without saying that various improvements and design changes are possible without departing from the scope of the present invention.
[0042]
【The invention's effect】
As is clear from the above description, according to the invention according to claim 1 of the present application, the preform can be handled in combination with a filter that supports the preform in the steps after the suction molding, so that the handleability of the preform is improved. Can be made. In addition, according to the present invention, the filter set in the slurry container during the preform suction molding process and the filter set in the mold container during the base metal melt impregnation process to the preform are combined. It is possible to improve the economical efficiency of the manufacturing method.
[0044]
Furthermore, according to the invention according to claim 2 of the present application, basically, the same effect as that of the invention according to claim 1 can be obtained. In this case, the filter is made of a metal similar to the base metal. Therefore, better machinability can be secured in the subsequent process.
[0045]
Furthermore, according to the invention of claim 3 of the present application, the filter is set at a state where the wettability of the base metal to the molten metal is low on at least the side facing the preform. During the impregnation of the base metal melt, insertion of the melt into the filter can be effectively suppressed.
[0046]
Furthermore, according to the invention of claim 4 of the present application, the filter is made of a material that can be oxidized during the firing step of the preform, and the oxidation causes an oxide layer to be generated on the pore surface of the filter. When the base metal melt is impregnated, insertion of the molten metal into the filter can be effectively suppressed.
[0047]
Furthermore, according to the invention according to claim 5 of the present application, since the filter is formed of graphite particles, the insertion of the molten metal into the filter is effectively suppressed when the molten metal is impregnated. Can do.
[0048]
Furthermore, according to the invention of claim 6 of the present application, before forming the preform by suction, the coating film is formed on the side of the filter facing the preform, so that the base metal melt is impregnated. Sometimes, the insertion of the molten metal into the filter can be effectively suppressed.
[0049]
Further, according to the invention according to claim 7 of the present application, before the preform is sucked, the dispersion medium in the slurry in which the graphite particles are dispersed is sucked and removed from the slurry container through the filter. Since the graphite particles are impregnated on the side of the filter facing the preform, the molten metal can be effectively prevented from being inserted into the filter when the base metal melt is impregnated.
[0050]
Furthermore, according to the invention according to claim 8 of the present application, since the filter is formed so as to have a volume ratio larger than the volume ratio of the preform, the filter is impregnated at the time of impregnation with the base metal melt. Insertion of molten metal into the inside can be effectively suppressed.
[Brief description of the drawings]
FIG. 1 (a) is an explanatory view showing a preform suction molding step in the method for producing a metal matrix composite member of the present invention.
(B) It is explanatory drawing showing the drying and baking process of the preform in the manufacturing method of the said metal matrix composite member.
(C) It is explanatory drawing showing the impregnation process of the base metal molten metal to the preform in the manufacturing method of the said metal matrix composite member.
FIG. 2 is an explanatory diagram showing an insertion portion of a base metal with respect to a filter and a cutting removal portion including an unnecessary filter and an insertion portion.
FIG. 3 is an explanatory view showing a filter having a coating mold formed on its surface side and a preform molded thereon.
4A is an explanatory view showing a step of sucking and removing a dispersion medium through a filter from a slurry in which graphite particles are dispersed prior to a preform suction molding step. FIG.
(B) It is explanatory drawing showing the suction molding process of a preform following the process shown to (a) of FIG.
[Explanation of symbols]
2 ... Slurry container 3 ... Reinforcement material 4 ... Binder 5 ... Dispersion medium 6 ... Slurry 7 ... Preform 9 ... Drying and firing furnace 10 ... Filter 12 ... Mold container 14 ... Base metal 22 ... Coating film 31 ... Graphite particle dispersed slurry 31a: Graphite particle impregnated portion

Claims (8)

In the method for producing a metal-based composite member obtained by impregnating a base metal with a porous preform composed of a preform material containing a reinforcing material,
The dispersion medium in the slurry in which the preform material is dispersed is removed by suction from the slurry container through a filter,
The preform formed on the filter by the suction removal is taken out from the slurry container together with the filter,
Drying the preform on the filter,
Set the preform in the mold container through the filter,
While pouring a melt of the base metal into the mold container, the inside of the mold container is depressurized from the opposite side of the filter to the preform, and the preform is filled with the base metal. A method for producing a metal-based composite member, wherein the molten metal is impregnated. The process according to claim 1, wherein the metal matrix composite member, characterized in that said filter is made of metal. 2. The method for producing a metal-based composite member according to claim 1, wherein the filter is set in a state in which wettability of the base metal to the molten metal is low on at least a side facing the preform. It comprises a step of firing after drying the preform,
4. The metal matrix composite member according to claim 3 , wherein the filter is made of a material that can be oxidized during the firing step of the preform, and an oxidation layer is formed on the pore surface of the filter by the oxidation. Method. 4. The method for producing a metal matrix composite member according to claim 3 , wherein the filter is formed of graphite particles. 4. The method for producing a metal matrix composite member according to claim 3 , wherein a coating film is formed on a side of the filter facing the preform before the preform is formed by suction. Prior to suction molding of the preform, the dispersion medium in the slurry in which the graphite particles are dispersed is sucked and removed from the slurry container through the filter, and the side of the filter facing the preform is impregnated with the graphite particles. The method for producing a metal matrix composite member according to claim 3 . The method for producing a metal matrix composite member according to any one of claims 1 to 7 , wherein the filter is formed to have a volume ratio larger than that of the preform.

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