Method and device for manufacturing silicon carbide aluminum-base composite materials with medium to high volume fractions

Abstract

The invention discloses a method for manufacturing silicon carbide aluminum-base composite materials with medium to high volume fractions. The volume fractions of the silicon carbide aluminum-base composite materials range from 45% to 70%, and a special pressure maintaining and air exhausting device is specially designed for the method. A pressure casting process is adopted in the method. The method includes steps that two silicon carbide materials with different particle sizes are used as raw materials and are manufactured into powder according to requirements on the volume fractions of silicon carbide and a mass ratio of 1:0.4-4, and the powder is uniformly mixed; a silicon carbide porous framework is manufactured under the pressure ranging from 0.1MPa to 15MPa; and molten aluminum is poured into a preheated female mold and infiltrates to the silicon carbide porous framework after being pressed, so that a silicon carbide aluminum-base composite material is acquired. The method has the advantages that the infiltration pressure of the molten aluminum can be reasonably controlled, so that shortcomings of aluminum band formation and the like are effectively overcome; and crystal particles of microstructures of the silicon carbide aluminum-base composite materials with the medium to high volume fractions are uniform, are nearly fully densified and are stable in performance, the method is simple, convenient and speedy, the device is reasonable in structure, and the silicon carbide aluminum-base composite materials can be easily manufactured in an industrialized manner.

Description

technical field [0001] The invention relates to a preparation technology of a silicon carbide aluminum-based composite material, specifically a method for preparing a medium-high volume silicon carbide aluminum-based composite material with a volume fraction of 45% to 70% and a device thereof. Background technique [0002] Aluminum matrix composites have excellent properties such as high strength, high hardness, and high modulus of elasticity. As a new type of functional material and engineering material, it has broad application prospects in aerospace and other fields. However, due to factors such as preparation costs, the wide application of aluminum matrix composites is limited. Realizing the industrialization of the preparation of aluminum matrix composites has always been the goal pursued by researchers. [0003] At present, the pressure infiltration method is an effective means to prepare aluminum matrix composites with high volume fraction. The pressure infiltratio...

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Problems solved by technology

[0005] However, the above-mentioned process has the following three defects, which affect the industrialization of the preparation of silicon carbide aluminum matrix composite materials:

[0006] 1. The silicon carbide porous skeleton prepared by the traditional process has low strength. When preparing the silicon carbide aluminum matrix composite material with a silicon carbide volume fraction of 45%~-60%, the silicon carbide skeleton is easy to collapse, resulting in the presence of aluminum strips in the silicon carbide aluminum matrix composite material. and other defects;

[0007] 2. The traditional process has no effective means to detect key performance indicators such as the apparent porosity and compressive strength of the silicon carbide porous framework;

[0008] 3. In the traditional process, the exhaust hole of the graphite carbon block bottom plate is in direct contact with the lower temperature workbench. This exhaust method has theoretical defects. Due to the complex pore network structure inside the silicon carbide porous skeleton, the gas It takes a while to be discharged from the silicon carbide porous skeleton by the extrusion of aluminum liquid; the aluminum liquid discharged through the vent hole of the graphite carbon block bottom plate along with the gas may block the vent hole in advance if the gas inside the silicon carbide porous skeleton is not completely removed , so that the gas cannot be completely discharged, resulting in a decrease in the yield of the silicon carbide aluminum matrix composite material

[0009] The above defects directly affect the yield of silicon carbide aluminum matrix composites and the stability of the properties of silicon carbide aluminum matrix composites, and even affect the industrialization of aluminum matrix composites.

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