JP2014210426A - Method of manufacturing preform used for manufacturing metal-ceramic composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a preform used for manufacturing a metal-ceramic composite material, capable of decreasing the unevenness of a molded surface of the metal-ceramic composite material.SOLUTION: A method of manufacturing a preform used for obtaining a metal-ceramic composite material by penetrating the preform composed of a ceramic with a metal base material, includes steps of: filling a cavity of a molding die with a wet mixture obtained by mixing ceramic particles with a liquid while covering at least a part with a water-transmitting body composed of a material hard to wet with the liquid; removing the excess liquid from the wet mixture through the water-transmitting body to make a wet formed body; and sintering the wet formed body.

Description

  The present invention relates to a method for manufacturing a preform used for manufacturing a metal-ceramic composite material.

  In recent years, metal-ceramic composite materials that use ceramic fibers, particles, and the like as reinforcing materials have attracted attention as the base metal. The metal-ceramic composite material has strength, ductility, toughness, formability, thermal conductivity, etc. of the base metal such as aluminum and aluminum alloy, and fibers and particles such as silicon carbide, aluminum nitride, and alumina as reinforcing materials. Because of the combination of rigidity, wear resistance, low thermal expansion, etc., made of ceramics, various parts such as transportation equipment parts, electronic parts, etc. that require light weight, high rigidity, wear resistance, high thermal conductivity, low thermal expansion, etc. It is used for products with various uses. As a method for producing the composite material, there are conventionally a powder metallurgy method, an infiltration method in which a molten metal serving as a base material is infiltrated into a preform which is a porous preform formed from ceramics, and the like.

  Among these, as a method for producing a preform used in the permeation method, a pressurization method, an extrusion method, an injection method, a mud casting method and the like are conventionally known. In each case, ceramic particles and binder solution are mixed and stirred in advance to prepare a wet mixture, which is supplied and filled into the cavity through the opening of the mold, molded by a method of removing the mold after being solidified, and after Is further manufactured by sintering in a heating furnace as necessary. The metal-ceramic composite material is produced by impregnating a preform with a molten metal serving as a base material. In this infiltration method, the preform is placed in a mold or the like having a cavity having a shape close to the product shape, filled with molten metal from the opening of the mold, and then pressed to forcibly impregnate the molten metal. Pressure infiltration method of taking out the product after solidifying the impregnated metal in the inside and by immersing the preform in the molten metal bath without using the mold for storing the preform, and pressurizing the metal in the bath After impregnating with the molten metal, the pressure infiltration method of solidifying after taking out from the metal bath, and immersing the preform in the molten metal bath without using the mold for storing the preform, There are non-pressure infiltration methods that impregnate the molten metal without pressing the metal and then solidify the impregnated metal after removal from the metal bath, which is advantageous in terms of manufacturing cost compared to powder metallurgy. Yes.

JP 2012-71548 A

  In recent years, metal-ceramic composite materials have been expected to be used as heat dissipation substrates for power semiconductors for trains and electric vehicles. In order to efficiently dissipate the heat generated from power semiconductors mounted in close contact therewith. Furthermore, the surface of the metal-ceramic composite material as the heat dissipation substrate is required to be particularly smooth. In response to this requirement, when a metal-ceramic composite material is obtained by a permeation method, a pressure permeation method in which a preform is placed in a mold having a shape close to the product shape and the product is taken out after the metal melt is infiltrated is a metal melt Since the molten metal to compensate for the solidification shrinkage is always supplied by pressurization, the surface of the product along the cavity surface of the mold is difficult to be uneven due to solidification shrinkage, and a smooth surface becomes a metal-rich skin layer. There is an advantage that it is easy to obtain. However, since it is necessary to prepare a number of molds corresponding to the number of production, it is not suitable for mass production and is disadvantageous in terms of cost.

  In contrast, the pressurized and non-pressurized penetrating methods that remove from the metal bath before solidification without using a mold do not require the preparation of a mold for each product. There is an advantage that the productivity is higher than the pressure infiltration method of taking out. However, the shrinkage accompanying solidification of the penetrated molten metal cannot be compensated. FIG. 1 is a schematic cross-sectional view for explaining the surface state of a metal / ceramic composite material made of a preform manufactured by the prior art. After completion of the solidification, it is inevitable that the ceramic particles 1 and the metal 2 form a concave meniscus as shown in FIG. For this reason, when compared with the case of ceramic particles having the same size, the surface roughness of the metal-ceramic composite tends to be larger than the pressure infiltration method in which the product is taken out after completion of solidification using a mold. For this reason, in the case of a product that requires particularly high smoothness such as a heat dissipation substrate, surface grinding is required up to the deepest bottom of the recess. In general, ceramics are very hard, so increasing the amount of removal processing not only accelerates the wear of the cutting blade but also significantly increases the processing time, which not only increases the manufacturing cost but also increases the dimensional accuracy of the product. It also causes variation. Therefore, it is necessary to make the fine depression on the surface as small as possible. Therefore, it is necessary to make the surface state of the preform made of the ceramic particles used as smooth as possible.

  However, in practice, the preform is molded by filling the mold in a wet mixture in which ceramic particles and a binder solution are premixed. FIG. 2 is a diagram showing a preform manufacturing method according to the prior art in the order of steps. In FIG. 2, when the mold is removed from the mold 3, some of the ceramic particles on the surface are detached while adhering to the surface of the mold, and the original part where the detached particles existed is depressed with respect to the molding surface. When the concave portion is formed and the detached ceramic particles adhere to another position on the preform molding surface again, a new convex portion is formed at that position. After the mold is removed from the mold, it is very difficult to correct these irregularities, so that the irregularities on the molding surface of the preform remain until the infiltration process for producing the metal-ceramic composite material. As a result, the unevenness of the molding surface becomes large, which not only significantly increases the cost of grinding, but also has a problem that the dimensional accuracy of the product is largely variable.

  On the other hand, a wet mixture obtained by mixing ceramic particles and a binder solution has poor productivity because it takes a long time for heating and drying to remove the excess liquid after molding as the ratio of the liquid that is the binder solution increases. Become. Therefore, a method of absorbing the surplus liquid in a hygroscopic sheet or the like, or a method of squeezing out by a method such as pressurization or suction under reduced pressure to quickly remove the surplus liquid can be considered. However, in the hygroscopic sheet, as the excess liquid moves to the hygroscopic sheet, some of the ceramic particles adhere to the hygroscopic sheet and remain attached to the hygroscopic sheet when the hygroscopic sheet is peeled off. There is a problem that unevenness is easily generated on the smooth surface, and some ceramic particles are likely to adhere to the mold by pressurization or suction under reduced pressure, and the tendency of the smoothness of the preform surface to be impaired is promoted.

As a prior art for removing excess liquid after forming a ceramic powder slurry in a mold, for example, Patent Document 1 discloses a thickness of 0.1 mm to 10.0 mm and an air permeability of 0.1 cm ³ / cm ^2. A step of injecting a slurry in which ceramic powder is dispersed into a mold comprising a filter made of a synthetic resin having a second to 50 cm ³ / cm ² · second and a support mold that supports the filter and has water permeability; There is disclosed a method for producing a ceramic product, comprising draining moisture through the filter and the support mold, and forming the ceramic compact by depositing the ceramic powder on the mold. Yes. However, although the quality of the demolding property by the material of the filter is described, the effect on the surface roughness of the ceramic molded body is not described.

  An object of this invention is to provide the manufacturing method of the preform used for manufacture of the metal-ceramic composite material which can make the unevenness | corrugation of the molding surface of a metal-ceramic composite material small.

  The present invention relates to a wet mixture obtained by mixing a liquid and ceramic particles in a preform manufacturing method used to obtain a metal-ceramic composite material by infiltrating a metal preform into a preform made of ceramics. Is filled in the cavity of the mold so as to be at least partially covered with the liquid-permeable liquid formed of the material difficult to wet with the liquid, and the excess liquid is removed from the wet mixture through the liquid-permeable liquid. This is a method for producing a preform in which a wet molded body is produced and sintered.

  According to the present invention, the above object can be achieved.

It is sectional drawing which illustrates typically the surface state of the metal-ceramics composite material produced by applying the preform manufactured by the prior art. It is a figure which shows the manufacturing method of the preform which concerns on a prior art in order of a process. FIG. 3 is a cross-sectional view schematically illustrating the surface state of a metal-ceramic composite material produced by applying a preform produced according to the present invention.

  The present inventors have noted that the reason why some ceramic particles adhere to the cavity surface of the mold is that the material constituting the cavity surface of the mold tends to get wet with the liquid covering the ceramic particles. . By making the material constituting the mold cavity difficult to wet with the liquid, it becomes easier to remove from the mold, and it is possible to prevent the ceramic particles from adhering to the mold, and the liquid itself is difficult to wet with the liquid. We found that after removing excess liquid through the liquid-permeable material composed of the material, removing this liquid-permeable liquid can remove the excess liquid without impairing the roughness of the surface that requires smoothness of the wet molded body. The present invention has been conceived.

  Below, the form for implementing this invention is demonstrated.

  The material of ceramic particles used for manufacturing a preform for obtaining a metal-ceramic composite material by infiltrating a base metal into a preform made of ceramics is silicon carbide, silicon nitride, nitriding Aluminum, alumina, barium titanate, lead zirconate titanate, zirconia, zircon, silica, mullite, cordierite, ferrite, steatite, etc. One type or two or more types of arbitrary shapes such as a teardrop shape, a spheroid shape, a flake shape, a fiber shape, and an indefinite shape.

  The liquid to be mixed with ceramic particles and stirred into a wet mixture is an inorganic binder or an organic binder aqueous solution, or an organic solution containing these binders as a solute and alcohol or organic solvent as a solvent. If it can be hardened to such an extent that it can be handled, a liquid containing no binder, that is, water, alcohol, or an organic solvent alone may be used. Any one of these liquids is mixed with ceramic particles by a known method and stirred to prepare a wet mixture.

  A mold, a resin mold, a gypsum mold, a wooden mold, a ceramic mold, or the like is used as a mold having a cavity for defining the wet mixture into a desired shape. At this time, all of the mold or all or part of the cavity surface of the mold may be formed of a liquid permeable liquid and a liquid that is difficult to wet, which will be described later. Also, in order to improve releasability even in a portion of the mold surface where the liquid permeability is not required, all or part of the cavity surface is made of a material that hardly wets the liquid, or the cavity surface Other liquid repellents such as tetrafluoroethylene may be preliminarily applied to all or a part of the above.

  Next, a method for filling the cavity of the mold in a state where the wet mixture is at least partially covered with a liquid permeable liquid formed of a material difficult to wet.

  First, the wet mixture is charged into the cavity from the opening of the mold and filled. In order to facilitate filling, the wet mixture may be mechanically pushed in using a tool such as a resin rod, or the mold may be vibrated during filling. Further, after a sufficient amount of the wet mixture is charged into the cavity having a desired shape, an operation of tamping the wet mixture from the opening of the mold may be performed in order to further ensure the filling.

  Next, the wet mixture in the opening of the mold is covered with a liquid permeable liquid (hereinafter, referred to as a hardly wettable liquid permeable liquid) formed of a liquid and a material difficult to wet. This difficult-to-wet permeable liquid is characterized in that the property of the material forming itself is difficult to wet with the above-mentioned liquid, and has a structure that has one or more through holes and allows the liquid to pass through. is there. As an index of wettability of the material forming the hardly wet permeable liquid, the contact angle with the liquid is preferably 80 ° or more, more preferably more than 90 °. Such materials include, for example, polypropylene, and the non-wetting permeable liquid formed thereby includes, for example, a non-woven fabric composed of polypropylene fibers or a polypropylene plate having one or more through holes. . In addition, a permeable liquid formed of a material that easily wets the liquid (hereinafter also referred to as an easily wettable permeable liquid) is applied by a method such as applying other lyophobic agent such as tetrafluoroethylene on the side in contact with the wet mixture. It can be used as a hardly wettable permeable liquid so as to be difficult to wet with the liquid.

  Further, if at least the material only on the side in contact with the ceramic particles is difficult to wet with the liquid, the poorly wettable permeable liquid may have a multilayer structure of two or more layers.

  In addition, when it is necessary to measure the contact angle when selecting a material to be applied to the hardly wettable permeable liquid, it is measured by a known method such as a sessile drop method, a meniscograph method, or a capillary method.

  Next, a method for smoothly leveling the wet mixture at the opening of the mold will be described. As a leveling method, other leveling tools such as a spatula, a press, a roller, or the like are used, or mechanically performed by rubbing a hardly wettable permeable liquid covering the wet mixture. In the leveling process, excess wet mixture that does not fit in the cavity is appropriately removed, and the amount of the wet mixture filled in the cavity is adjusted to be more appropriate. At this time, when excess liquid oozes out of the wet mixture in the cavity through the hardly wettable permeable liquid, the leveling operation is performed while removing the liquid appropriately. The step of smoothening the wet mixture may be performed to some extent before the step of covering the opening of the mold with the hardly wettable liquid-permeable liquid.

  Next, when it is necessary to remove excess liquid from the mold from the wet molded body, a method of appropriately removing the liquid that exudes from the hard-to-wet permeable liquid in the leveling step, or molding A small hole communicating with the outside of the mold is provided in a part of the mold, or a part of the mold is replaced with a hardly wet permeable liquid, and the inside of the cavity is exuded and removed by pressurization or decompression. By the method. At this time, when the ceramic particles and the liquid constituting the wet molded body are difficult to wet each other, the liquid is likely to exude excessively through the poorly wettable permeable liquid, so that it is difficult to adjust the liquid to a desired content. For this reason, the ceramic particles and the liquid are easily wetted with each other, that is, the contact angle between the ceramic and the liquid is preferably less than 80 °, and more preferably less than 70 °.

  In the step of removing the hardly wettable permeable liquid after adjusting the wet molded body to a desired liquid content, the hardly wettable permeable liquid and the liquid are difficult to wet each other. Difficult to adhere to hard-to-wet permeable liquid. That is, the concave portion due to the falling off of the ceramic particles is hardly formed on the surface of the wet molded body that has been in contact with the hardly wettable liquid-permeable liquid. In addition, as another method of removing the hardly wettable liquid permeable liquid, a method of burning and eliminating the poorly wettable liquid permeable liquid in a sintering process described later may be used.

  Then, after the wet molded body is cured to a handleable strength, it is removed from the mold and sintered to form a preform. When a heat-resistant mold such as a mold or a ceramic mold is used, the mold may be heated after being heated and sintered to form a preform and then removed.

  The preform produced by the above method is impregnated with a liquid metal by a known permeation method such as a pressure permeation method or a non-pressure permeation method without using a mold to obtain a metal-ceramic composite material.

  The surface of the metal-ceramic composite material thus obtained is free from detachment or disturbance of the ceramic particles on the preform molding surface. FIG. 3 is a cross-sectional view schematically illustrating the surface state of a metal-ceramic composite material produced by applying a preform produced according to the present invention. As shown in FIG. 3, the depression due to the metal and the meniscus formed becomes smaller and smoother than the surface according to the prior art shown in FIG.

  Hereinafter, although the embodiment of the present invention will be described in detail for each form in which the particle diameter of the ceramic particles is variously changed, the present invention is not limited thereto.

[Embodiment 1]
Example 1
The ceramic particles are amorphous silicon carbide (green carborundum, hereinafter the same applies to other embodiments) having an equivalent aperture of 450 μm, and the liquid is water glass as a binder (manufactured by Fuji Chemical, No. 2, In the following, the same applies to other embodiments), and a water glass aqueous solution was prepared by diluting and mixing with water at a volume ratio of 1: 5. Next, a water glass aqueous solution was mixed at a rate of 10 cm ³ with respect to 100 g of silicon carbide particles, and stirred to obtain a wet mixture.

  The mold for filling the wet mixture was a mold, and the cavity shape was 50 mm long, 80 mm wide, and 7 mm deep. Tetrafluoroethylene, which is a lyophobic agent, was applied to the cavity surface.

  First, a wet mixture having a weight corresponding to a volume slightly exceeding the volume of the mold cavity is introduced from the opening surface of the mold cavity, and the resin round bar is expanded while being mechanically vibrated. It was filled evenly. At this time, the excess wet mixture that did not fit in the cavity was appropriately removed.

  Next, a non-woven fabric made of polypropylene having a length of 60 mm and a width of 90 mm (hereinafter also referred to as a polypropylene non-woven fabric) is placed on and covered on the entire surface of the above-mentioned leveled surface as a non-wetting liquid. The round bar was placed on the cavity surface and rolled to bring the non-woven fabric and the wet mixture surface just below it into intimate contact, and the wet mixture was sufficiently leveled to obtain a wet molded body. At this time, since the excess water glass aqueous solution oozed out from the nonwoven fabric, it was sucked with a dropper and removed while being absorbed by a sponge.

  Next, the nonwoven fabric was peeled off from the wet molded body. Since the water glass aqueous solution adhering to the surface of the silicon carbide particles of the wet molded body was difficult to wet the nonwoven fabric, it could be removed cleanly without the silicon carbide particles adhering to the peeled nonwoven fabric.

  Then, carbon dioxide gas is blown onto the wet molded body, the wet molded body is cured to such an extent that it can be removed from the mold, then removed, transferred to a heat-resistant tray, and then baked in a heating furnace at 850 ° C. for 2 hours and then cooled to room temperature. And made a preform.

  The preform was preheated to 730 ° C., while an aluminum alloy (Al-12% Si-3% Mg in mass ratio) was melted in an electric melting furnace to produce a molten metal having a weight of 20 kg and a temperature of 750 ° C. The preheated preform is immersed in a molten aluminum alloy in an electric melting furnace at atmospheric pressure and atmospheric pressure, held for 1.5 hours to infiltrate the aluminum alloy, then removed from the electric melting furnace, solidified and cooled. It was. Thus, an aluminum alloy-silicon carbide composite material in which the base material of the aluminum alloy was reinforced with silicon carbide was obtained.

  Next, Table 1 shows the results of measuring the surface roughness of the surface of the aluminum alloy-silicon carbide composite material that was covered with the polypropylene nonwoven fabric when the preform was produced. The surface roughness was measured using a stylus type surface roughness meter. Hereinafter, the surface roughness values for the other examples and comparative examples in this embodiment, and the examples and comparative examples in other embodiments are also the same as the wettability permeable liquid or the The surface measured with the wettable permeable liquid is measured by the same method.

  On the other hand, in Comparative Example 1 of Table 1, the liquid permeation covered at the time of preform molding is changed to the polypropylene nonwoven fabric used in Example 1, and Japanese paper with a length of 60 mm and a width of 80 mm, which is an easily wettable liquid, is used. It is the surface roughness of an aluminum alloy-silicon carbide composite material produced by producing a preform. In addition to the above, other materials and manufacturing conditions used are the same as those in Example 1.

  Rz (maximum height roughness) of Example 1 was 58 μm, whereas Comparative Example 1 was 82 μm, and Example 1 was 24 μm smaller than Comparative Example 1. In Comparative Example 1, some silicon carbide particles adhered to and separated from the Japanese paper in the process of peeling the Japanese paper. Therefore, the unevenness of the smoothed surface of the preform is larger than that of Example 1, and the surface roughness is larger than that of Example 1 even in the state of the aluminum alloy-silicon carbide composite material.

  As described above, in Example 1, the use of the polypropylene non-woven fabric that is a liquid with poor wettability allows the surface roughness when the aluminum alloy-silicon carbide composite material is made to be smaller than that in Comparative Example 1. It was.

(Example 2)
Silicon carbide particles having the same particle diameter as in Example 1 and a water glass aqueous solution having the same blending ratio as in Example 1 were prepared, and both were mixed and stirred at the same ratio as in Example 1 to obtain a wet mixture. Also, the mold and the cavity shape filled with silicon carbide particles, and the lyophobic agent applied to the cavity surface are the same as those in Example 1, and the method of charging the wet mixture into the cavity of the mold, the method of leveling the wet mixture, the surplus In the same manner as in Example 1, the method of removing the wet mixture was filled in the cavity.

  As the hardly wettable permeable liquid, a polypropylene plate (hereinafter also referred to as a polypropylene plate) having a length of 60 mm, a width of 90 mm, and a thickness of 5 mm, in which through holes having a diameter of 0.2 mm were formed at a pitch of 10 mm, was used. The polypropylene plate was covered and brought into close contact with the entire surface of the wet mixture which had been filled in the mold and leveled. Furthermore, an operation of leveling the wet mixture was performed while sliding the polypropylene plate to obtain a wet molded body. At this time, the water glass aqueous solution exuded from the polypropylene plate was appropriately removed.

  Next, this polypropylene plate was peeled off from the wet molded body. Since the water glass aqueous solution adhering to the surface of the silicon carbide particles of the wet molded body was difficult to wet with the polypropylene plate, it could be removed cleanly without the silicon carbide particles adhering to the peeled polypropylene plate.

  The wet molded body was hardened with carbon dioxide gas in the same operation as in Example 1 and removed, and a preform was obtained in the same operation as in Example 1. Then, the aluminum alloy-silicon carbide composite was operated in the same operation as in Example 1. The material was obtained. Table 1 shows the surface roughness of this aluminum alloy-silicon carbide composite as Example 2.

  On the other hand, in Comparative Example 2 of Table 1, the liquid permeation covered at the time of preform molding is changed to the polypropylene plate used in Example 2, and a through-hole having a diameter of 0.2 mm, which is a wettable liquid permeation, is used. Aluminum alloy-silicon carbide composite material produced by producing a preform using a PET (polyethylene terephthalate) plate (hereinafter also referred to as a PET plate) having a length of 60 mm, a width of 90 mm, and a thickness of 5 mm opened at a pitch of 10 mm. The surface roughness. The other materials used in addition to the above and the production conditions are the same as in Example 2.

  Rz (maximum height roughness) of Example 2 was 62 μm, while Comparative Example 2 was 81 μm, and Example 2 was 19 μm smaller than Comparative Example 1. In Comparative Example 2, in the process of peeling the PET plate, some silicon carbide particles adhered to the PET plate and detached. Therefore, the unevenness of the uniform surface of the preform is larger than that of Example 2, and the surface roughness is larger than that of Example 2 even in the state of the aluminum alloy-silicon carbide composite material.

  As described above, in Example 2, the use of a polypropylene plate that is a liquid with poor wettability allows the surface roughness when the aluminum alloy-silicon carbide composite material is made to be smaller than that in Comparative Example 2. It was.

Example 3
Silicon carbide particles having the same particle diameter as in Example 1 and a water glass aqueous solution having the same blending ratio as in Example 1 were prepared, and both were mixed and stirred at the same ratio as in Example 1 to obtain a wet mixture. Also, the mold and the cavity shape filled with silicon carbide particles, and the lyophobic agent applied to the cavity surface are the same as those in Example 1, and the method of charging the wet mixture into the cavity of the mold, the method of leveling the wet mixture, the surplus In the same manner as in Example 1, the method of removing the wet mixture was filled in the cavity.

  The non-wetting permeable liquid is obtained by applying tetrafluoroethylene as a lyophobic agent to one side of a PET plate having a length of 60 mm, a width of 90 mm, and a thickness of 5 mm with through-holes having a diameter of 0.2 mm at a pitch of 10 mm (hereinafter referred to as tetra (Also referred to as a fluoroethylene-coated PET plate). When the contact angle of the PET plate on the surface coated with tetrafluoroethylene was measured by the sessile drop method, it was 105 °.

  The tetrafluoroethylene-coated PET plate was placed on the entire surface of the wet mixture that had been filled in the mold and leveled, and brought into close contact. Further, the wet mixture was smoothed while sliding the tetrafluoroethylene-coated PET plate to obtain a wet molded body. At this time, the water glass aqueous solution which exuded from the tetrafluoroethylene-coated PET plate was appropriately removed.

  Next, the tetrafluoroethylene-coated PET plate was peeled off from the wet molded body. Since the water glass aqueous solution adhering to the silicon carbide particle surface of the wet molded body is difficult to wet with the tetrafluoroethylene-coated surface of the tetrafluoroethylene-coated PET plate, the peeled tetrafluoroethylene-coated PET plate has a silicon carbide The particles could be removed cleanly without adhering.

  The wet molded body was hardened with carbon dioxide gas in the same operation as in Example 1 and removed, and a preform was obtained in the same operation as in Example 1. Then, the aluminum alloy-silicon carbide composite was operated in the same operation as in Example 1. The material was obtained. The surface roughness of this aluminum alloy-silicon carbide composite is shown in Table 1 as Example 3.

  Rz (maximum height roughness) was 61 μm in Example 3, while 81 μm was carried out in Comparative Example 2 using an easily wettable liquid-permeable PET plate not coated with a lyophobic tetrafluoroethylene. Example 3 was 20 μm smaller than Comparative Example 2.

  As described above, in Example 3, an aluminum alloy-silicon carbide composite material is obtained by applying tetrafluoroethylene, which is a lyophobic agent, to a PET plate, which is an easily wettable liquid, so that the liquid is a poorly wettable liquid. As a result, the effect of reducing the surface roughness compared to Comparative Example 2 was obtained.

[Embodiment 2]
Example 4
The ceramic particles are amorphous silicon carbide having an aperture equivalent diameter of 150 μm, and the liquid that covers the preform is made of the same polypropylene non-woven fabric as in Example 1 of the first embodiment. A preform was prepared in the same manner as in Example 1 to obtain an aluminum alloy-silicon carbide composite material. Table 2 shows the surface roughness of the aluminum alloy-silicon carbide composite as Example 4.

  On the other hand, Comparative Example 3 in Table 2 is a PET plate that is the same wettable permeable liquid as Comparative Example 2 in Embodiment 1 by replacing the liquid permeation covered during preform molding with the polypropylene nonwoven fabric used in Example 4. The surface roughness of the aluminum alloy-silicon carbide composite material produced by making a preform using The other materials and manufacturing conditions used in addition to the above are the same as in Example 4.

  Rz (maximum height roughness) of Example 4 was 45 μm, whereas Comparative Example 3 was 63 μm, and Example 4 was 18 μm smaller than Comparative Example 3. In Comparative Example 3, a part of the silicon carbide particles adhered to and desorbed from the easily wettable liquid in the process of peeling the easily wettable liquid. Therefore, the unevenness of the smoothed surface of the preform is larger than that of Example 4, and the surface roughness is larger than that of Example 4 even when the preform is an aluminum alloy-silicon carbide composite material.

  As described above, in Example 4, the effect of reducing the surface roughness as an aluminum alloy-silicon carbide composite material as compared with Comparative Example 3 is obtained by using a polypropylene nonwoven fabric that is a hardly wettable liquid. It was.

(Example 5)
The ceramic particles are amorphous silicon carbide having an aperture equivalent diameter of 150 μm, and the liquid that is covered during the molding of the preform is the same tetrafluoroethylene-coated PET plate as in Example 3 in Embodiment 1, and other materials, A preform was produced under the same manufacturing conditions as in Example 4 to obtain an aluminum alloy-silicon carbide composite material. Table 2 shows the surface roughness of this aluminum alloy-silicon carbide composite as Example 5.

  Rz (maximum height roughness) of Example 5 was 42 μm, while Comparative Example 3 was 63 μm, and Example 5 was 21 μm smaller than Comparative Example 3.

  As described above, in Example 5, an aluminum alloy-silicon carbide composite material was obtained by applying tetrafluoroethylene, which is a lyophobic agent, to a PET plate, which is an easily wettable liquid, so that the liquid is a poorly wettable liquid. As a result, the surface roughness was smaller than that of Comparative Example 3.

  The surface roughness 63 μm of Comparative Example 3 was a value close to Example 2 (62 μm) and Example 3 (61 μm) shown in the first embodiment. This is because the diameter is 150 μm, which is finer than 450 μm in the first embodiment, and is not due to the effect of the present invention in which the silicon carbide particles were not detached as in Example 2 and Example 3.

[Embodiment 3]
(Example 6)
The ceramic particles are amorphous silicon carbide having an opening equivalent diameter of 60 μm, and the liquid permeable to cover at the time of preform molding is the same polypropylene non-woven fabric as in Example 1 of the first embodiment. A preform was produced in the same manner as 1 to obtain an aluminum alloy-silicon carbide composite material. Table 3 shows the surface roughness of the aluminum alloy-silicon carbide composite as Example 6.

  On the other hand, in Comparative Example 4 in Table 3, the liquid permeation covered at the time of preform molding is changed to the same polypropylene non-woven fabric as that used in Example 6 and the same wettable liquid permeation as in Comparative Example 2 in Embodiment 1. The surface roughness of an aluminum alloy-silicon carbide composite material produced by producing a preform using a PET plate. In addition to the above, other materials and manufacturing conditions used are the same as in Example 6.

  Rz (maximum height roughness) of Example 6 was 29 μm, while Comparative Example 4 was 38 μm, and Example 6 was 9 μm smaller than Comparative Example 4. In Comparative Example 4, some silicon carbide particles adhered to and detached from the PET plate in the process of peeling the PET plate. Therefore, the unevenness of the smoothed surface of the preform is larger than that in Example 6, and the surface roughness is larger than that in Example 6 even in the state of the aluminum alloy-silicon carbide composite material.

  As described above, Example 6 has an effect that the surface roughness as the aluminum alloy-silicon carbide composite material is smaller than that of Comparative Example 4 by using the polypropylene nonwoven fabric which is a liquid with poor wettability. It was.

(Example 7)
The ceramic particles are amorphous silicon carbide having an opening equivalent diameter of 60 μm, and the liquid that is covered during the molding of the preform is the same tetrafluoroethylene-coated PET plate as in Example 3 in Embodiment 1, and other materials, A preform was produced under the same manufacturing conditions as in Example 6 to obtain an aluminum alloy-silicon carbide composite material. Table 3 shows the surface roughness of the aluminum alloy-silicon carbide composite as Example 7.

  Rz (maximum height roughness) of Example 7 was 27 μm, while Comparative Example 4 was 38 μm, and Example 7 was 11 μm smaller than Comparative Example 4.

  As described above, in Example 7, the surface roughness of the aluminum alloy-silicon carbide composite material is smaller than that in Comparative Example 4 by using the tetrafluoroethylene-coated PET plate that is a hardly wettable liquid. The effect was obtained.

  The surface roughness of Comparative Example 4 was 38 μm, which was smaller than Examples 1-2 shown in Embodiment 1 and Examples 4-5 shown in Embodiment 2, for the reason. The silicon carbide particles have a particle size of 60 μm, 450 μm in the first embodiment, and 150 in the second embodiment, and are smaller than 150 in the first embodiment. This was not due to the effect of the present invention in which the particles were not detached.

[Embodiment 4]
(Example 8)
The ceramic particles are prepared by mixing two types of amorphous silicon carbide having an aperture equivalent diameter of 150 μm and 60 μm in a weight ratio of 3: 1, respectively. The same polypropylene non-woven fabric as in Example 1 was used, and other materials and production conditions were the same as in Example 1 to produce a preform to obtain an aluminum alloy-silicon carbide composite material. Table 4 shows the surface roughness of this aluminum alloy-silicon carbide composite as Example 8.

  On the other hand, Comparative Example 5 in Table 4 is a PET plate that is the same wettable permeable liquid as Comparative Example 2 in Embodiment 1 by replacing the liquid permeation covered during preform molding with the polypropylene nonwoven fabric used in Example 8. The surface roughness of the aluminum alloy-silicon carbide composite material produced by making a preform using The other materials and manufacturing conditions used in addition to the above are the same as in Example 8.

  Rz (maximum height roughness) of Example 8 was 42 μm, while Comparative Example 5 was 57 μm, and Example 8 was 15 μm smaller than Comparative Example 5. In Comparative Example 5, in the process of peeling the PET plate, some silicon carbide particles adhered to the PET plate and detached. Therefore, the unevenness of the smoothed surface of the preform is larger than that of Example 8, and the surface roughness is larger than that of Example 8 even in the state of the aluminum alloy-silicon carbide composite material.

  As described above, in Example 8 in which silicon carbide particles having two types of opening equivalent diameters were mixed, a surface as an aluminum alloy-silicon carbide composite material was obtained by using a polypropylene non-woven fabric which is a hardly wettable liquid. The effect that the roughness is smaller than that of Comparative Example 5 was obtained.

Example 9
The ceramic particles are prepared by mixing two types of amorphous silicon carbide having an aperture equivalent diameter of 150 μm and 60 μm in a weight ratio of 3: 1, respectively. The same tetrafluoroethylene-coated PET plate as in Example 3 was used, and other materials and production conditions were the same as in Example 8. A preform was produced to obtain an aluminum alloy-silicon carbide composite material. Table 4 shows the surface roughness of this aluminum alloy-silicon carbide composite as Example 9.

  Rz (maximum height roughness) of Example 9 was 35 μm, while Comparative Example 5 was 57 μm, and Example 9 was 22 μm smaller than Comparative Example 5.

  As described above, even in Example 9 in which silicon carbide particles having two types of openings having equivalent diameters were mixed, by using a tetrafluoroethylene-coated PET plate which is a hardly wettable liquid, an aluminum alloy-silicon carbide The effect that the surface roughness as a composite material becomes smaller than that of Comparative Example 5 was obtained.

  The surface roughness (57 μm) of Comparative Example 5 was a smaller value than Examples 1 to 3 shown in the first embodiment because the silicon carbide particles had particle sizes of 150 μm and 60 μm. The two types of mixing were due to the fineness of 450 μm in the first embodiment, and were not due to the effect of the present invention in which the silicon carbide particles were not detached as in Examples 1 to 3.

[Embodiment 5]
(Example 10)
The ceramic particles are prepared by mixing two types of amorphous silicon carbide having an aperture equivalent diameter of 150 μm and 10 μm in a weight ratio of 3: 1, respectively. The same polypropylene non-woven fabric as in Example 1 was used, and other materials and production conditions were the same as in Example 1 to produce a preform to obtain an aluminum alloy-silicon carbide composite material.

  On the other hand, Comparative Example 6 in Table 5 is a PET plate that is the same wettable permeable liquid as Comparative Example 2 in Embodiment 1 by replacing the liquid permeable to be covered during preform molding with the polypropylene nonwoven fabric used in Example 10. The surface roughness of the aluminum alloy-silicon carbide composite material produced by making a preform using The other materials and manufacturing conditions used in addition to the above are the same as in Example 10.

  Rz (maximum height roughness) of Example 10 was 49 μm, whereas Comparative Example 6 was 65 μm, and Example 10 was 16 μm smaller than Comparative Example 6. In Comparative Example 6, some silicon carbide particles adhered to the PET plate in the process of peeling the PET plate. Therefore, the unevenness of the smoothed surface of the preform is larger than that of Example 10, and the surface roughness is larger than that of Example 10 even in the state of the aluminum alloy-silicon carbide composite material.

  As described above, in Example 10 in which silicon carbide particles having two types of opening equivalent diameters were mixed, a surface as an aluminum alloy-silicon carbide composite material was obtained by using a polypropylene non-woven fabric which is a hardly wettable liquid. The effect that the roughness was smaller than that of Comparative Example 6 was obtained.

(Example 11)
The ceramic particles are prepared by mixing two types of amorphous silicon carbide having an aperture equivalent diameter of 150 μm and 10 μm in a weight ratio of 3: 1, respectively. The same tetrafluoroethylene-coated PET plate as in Example 3 was used, and the other materials and production conditions were the same as in Example 10 to obtain an aluminum alloy-silicon carbide composite material. Table 5 shows the surface roughness of the aluminum alloy-silicon carbide composite as Example 11.

  Rz (maximum height roughness) of Example 11 was 46 μm, while Comparative Example 6 was 65 μm, and Example 11 was 19 μm smaller than Comparative Example 6.

  As described above, also in Example 11 in which the silicon carbide particles having two types of opening equivalent diameters were mixed, the use of the tetrafluoroethylene-coated PET plate that is a liquid with poor wettability allows the aluminum alloy-silicon carbide. The effect that the surface roughness as a composite material becomes smaller than that of Comparative Example 6 was obtained.

  The surface roughness (65 μm) of Comparative Example 6 was a value close to that of Example 2 (62 μm) and Example 3 (61 μm) shown in the first embodiment. In the embodiment, the particle size of the silicon carbide particles is a mixture of two types of 150 μm and 10 μm, both of which are due to the fine particles compared to 450 μm in the first embodiment. Thus, it was not due to the effect of the present invention that the silicon carbide particles were not detached.

1: Ceramic particles 2: Metal 3: Part of mold

Claims (3)

  In a preform manufacturing method used to obtain a metal-ceramic composite material by infiltrating a base metal into a preform made of ceramic, a wet mixture obtained by mixing a liquid and ceramic particles is used as the liquid. The mold cavity is filled in a state where at least a part thereof is covered with a permeable liquid formed of a material that is difficult to wet, and excess wet liquid is removed from the wet mixture through the permeable liquid. A method for producing a preform, characterized in that the method is manufactured and sintered.   The method for manufacturing a preform according to claim 1, wherein the liquid and the ceramic are easily wetted with each other.   The method for producing a preform according to claim 2, wherein the ceramic particles are silicon carbide particles.

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