JP-7855284-B1 - Aluminum alloy matrix composite material, method for manufacturing aluminum alloy matrix composite material

JP7855284B1JP 7855284 B1JP7855284 B1JP 7855284B1JP-7855284-B1

Abstract

[Problem] To provide an aluminum alloy matrix composite material that is easily impregnated with aluminum alloy and has good mechanical properties, and a method for manufacturing an aluminum alloy matrix composite material. [Solution] Primary ceramic particles are obtained by crushing the ceramic raw material with a jet mill (S1). The volume average diameter of the primary ceramic particles is adjusted to 0.1 to 10 μm. Next, an organic binder and an inorganic binder are added to an aqueous slurry using the primary ceramic particles to obtain a slurry. The obtained slurry is granulated using a known spray-drying method to obtain secondary ceramic particles (pseudoparticles). Next, a preform is formed using the obtained ceramic particles (S2). Next, molten aluminum alloy is pressure-impregnated into the obtained preform (S3). By doing so, an aluminum alloy matrix composite material can be obtained. [Selection Diagram] Figure 1

Inventors

高木義夫
舩本玄喜
北村仁
服部淳一

Assignees

アドバンスコンポジット株式会社

Dates

Publication Date: 20260508
Application Date: 20251125

Claims (8)

A metal matrix composite material in which an aluminum alloy is impregnated into a preform consisting of reinforcing particles, The reinforcing particles are formed by granulating primary particles, An aluminum alloy matrix composite material characterized in that, in the number-based distribution of the reinforcing particles, where the circularity = 4πA/ P² obtained from the projected area A and circumference P based on image analysis, the circularity of C10 is 0.80 or more and 1.0 or less , and the circularity of C50 is 0.93 or more and 1.0 or less .
The aluminum alloy matrix composite material according to claim 1, characterized in that, in the volume-based particle size distribution of the reinforcing particles, D10 is 10 μm or more and D90 is 90 μm or less.
The aluminum alloy matrix composite material according to claim 1, characterized in that the volume fraction Vf of the reinforcing particles relative to the total volume of the aluminum alloy and the reinforcing particles is 32% or more and 80% or less.
The aluminum alloy matrix composite material according to claim 1, characterized in that the circularity distribution of the reinforcing particles is (C90-C10)/C50 of 0.20 or less.
The aluminum alloy matrix composite material according to claim 1, characterized in that the reinforcing particles contain at least one of the following: alumina, mullite, cordierite, silicon nitride, magnesium borate, aluminum borate, silicon carbide, spinel, metallic silicon, carbon, or graphite.
The aluminum alloy matrix composite material according to claim 1, characterized by having a tensile strength of 300 MPa or more and a bending strength of 500 MPa or more.
The aluminum alloy matrix composite material according to claim 1, characterized in that the density of the aluminum alloy matrix composite material is 2.9 g/ cm³ or more and 3.1 g/ cm³ or less.
A method for producing an aluminum alloy matrix composite material according to any one of claims 1 to 7, A process of crushing the reinforced particle raw material to adjust the volume average diameter of the primary particles to 0.1 to 10 μm, A process of using primary particles, forming a slurry containing water and a binder, spray-drying it to obtain secondary particles, and forming a preform of the secondary particles, The process involves pressure-impregnating the preform with molten aluminum alloy, A method for manufacturing an aluminum alloy matrix composite material, characterized by comprising the following:

Description

This invention relates to a metal matrix composite material in which an aluminum alloy is used as the matrix material and reinforcing particles are dispersed, and to a method for producing the same. Conventionally, metal matrix composites (MMCs) have been proposed and partially put into practical use. These MMCs are created by pressure-impregnating a ceramic powder-filled or binder-solidified intermediate molded body (preform) with molten aluminum alloy, thereby compounding it with ceramic as a reinforcing phase. In this method, the molten metal penetrates the voids within the preform under pressure, reducing residual pores, and rapid cooling homogenizes the metal structure, making it easier to obtain MMCs with high strength and low strength variation. One proposed method for manufacturing such metal matrix composite materials involves filling a porous container with aluminum borate powder with a central particle size of approximately 30 to 50 μm, and then impregnating it by pouring and pressurizing molten aluminum alloy in a mold (Patent Document 1). Furthermore, a method has been proposed to obtain MMC by molding and drying a slurry consisting of aluminum borate powder and a binder, and then impregnating it with molten aluminum alloy under high pressure (Patent Document 2). Japanese Patent Publication No. 2019-099850Japanese Patent Publication No. 2020-196932 A diagram illustrating the manufacturing process of aluminum alloy matrix composite materials.SEM image of granulated ceramic particles.SEM image of granulated ceramic particles.SEM image of ungranulated ceramic particles.SEM image of ungranulated ceramic particles.Optical microscope image of a composite material using granulated ceramic particles.Optical microscope image of a composite material using non-granulated ceramic particles.A figure showing the evaluation results of bending strength.A diagram showing the evaluation results of tensile strength.A figure showing the results of density evaluation. The embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a diagram showing the manufacturing process of the aluminum alloy matrix composite material according to this embodiment. (primary particles) First, the reinforcing particle material is crushed in a jet mill to obtain primary particles (S1). In this embodiment, the reinforcing particle material is a ceramic material, and an example of obtaining primary ceramic particles is described, but other materials such as metallic silicon, carbon, and graphite can also be used. Furthermore, while this embodiment describes an example where aluminum borate is used as the ceramic raw material, at least one selected from alumina, mullite, cordierite, silicon nitride, magnesium borate, aluminum borate, silicon carbide, spinel, etc., is acceptable. Among these, the present invention is particularly effective for aluminum borate, silicon carbide, and spinel, which tend to form pointed protrusions in their particles when crushed. The volume-average diameter of the primary ceramic particles is preferably 0.1 to 10 μm. Furthermore, the volume-average diameter of the primary ceramic particles should be set to approximately 1/10 to 1/1000 of the volume-average diameter of the secondary ceramic particles, as described later. The volume-average diameter of the primary ceramic particles can be adjusted by optimizing the grinding conditions or by sieving the resulting particles. (Secondary ceramic particles) Next, an organic binder (e.g., polyvinyl alcohol) and an inorganic binder (e.g., colloidal silica, colloidal alumina) are added to the primary ceramic particles in an aqueous slurry to obtain a slurry. The type and amount of binder used are selected as appropriate. Using the obtained slurry, primary ceramic particles are granulated using a known spray-drying method to obtain secondary ceramic particles (pseudoparticles). Spray-drying is a technique that involves spraying a liquid raw material (slurry) into hot air to instantly evaporate the water and obtain dried particles. For example, it can be manufactured under conditions of a disc diameter of φ65 mm, a rotation speed of 10,000 to 25,000 rpm, an inlet temperature of 80°C to 350°C, an outlet temperature of 50°C to 250°C, and a differential pressure of -0.2 to -0.3 kPa. However, the conditions for the spray-drying method are not limited to those above; the conditions can be appropriately set depending on the equipment, the secondary ceramic particles, and their size. In this way, secondary ceramic particles (hereinafter, these reinforced particles may simply be referred to as ceramic particles) can be obtained using the primary ceramic particles obtained by pulverization. The volume-average diameter of the granulated ceramic particles is preferably 10 to 120 μm. The volume-average diameter of ceramics can be analyzed using known laser diffraction methods or dynamic image analysis. When evaluating using image analys