High-entropy alloy particle refined and reinforced aluminum-based composite material and preparation method thereof

Abstract

The invention discloses a high-entropy alloy particle refined and reinforced aluminum-based composite material and a preparation method thereof. According to the material, high-entropy alloy particles prepared after mechanical alloying are added into a molten aluminum alloy substrate through a gas dispersing and stirring device to be stirred and dispersed, then vibration degassing is carried out, and finally a casting technology is adopted to prepare a formed part of the high-entropy alloy particle reinforced aluminum-based composite material. According to the process, the high-entropy alloy particles added into the melt are dispersed through the gas dispersing and stirring device, the contact area and wettability of the high-entropy alloy particles and aluminum alloy are increased, agglomeration is avoided, macroscopic and microscopic dispersion is uniform, the interface bonding property is improved, nucleation particles are greatly increased in the whole substrate during solidification, grains are refined, the structure is improved, and the performance is enhanced.

Description

technical field [0001] The invention relates to a high-entropy alloy particle-reinforced aluminum-based composite material and a stirring casting preparation process thereof, belonging to the field of metal-based composite material preparation. Background technique [0002] The composite materials used as reinforcement phase are mostly ceramic particles, fibers, metal particle fibers, etc. These composite materials often have good strength and toughness, but there are still many problems, such as the relationship between ceramic particles and fiber reinforcements and aluminum matrix. Poor wettability, poor interfacial bonding, and uneven particle distribution have seriously affected the large-scale production and popularization of aluminum matrix composites for structural applications. [0003] High-entropy alloy is a new type of multi-principal alloy composed of five or more elements, and the molar mass of each element is equal or nearly equal. Therefore, high-entropy allo...

AI Technical Summary

Problems solved by technology

The liquid stirring method has great advantages in preparing and forming large-scale composite materials, but it is difficult to uniformly disperse the high-entropy alloy particles into the matrix by using the liquid stirring method. The high-entropy alloy particles have a large specific surface area. In the conventional stirring and powdering method, the high-entropy alloy particles tend to float on the surface of the melt, and cannot wet and disperse well with the aluminum alloy matrix at high temperature

Patent CN201510988188.X seals the high-entropy alloy particles into the aluminum alloy tube, then adds the segmented aluminum alloy tubes into the molten matrix, and then stirs and disperses. This patent uses the high-entropy alloy particles to be wrapped and pressed into the aluminum alloy matrix Stirring is carried out to prevent the particles from floating to the surface of the material, but there are certain problems. The reason is that when the aluminum alloy tube is melted, the high-entropy alloy particles are still in contact with the aluminum alloy matrix in the form of a large number of agglomerates. Insufficient contact still has the problem of poor dispersion and poor wetting. Pure mechanical stirring can only disperse the high-entropy alloy particles macroscopically, and its microscopic dispersion is not uniform. There will still be a large number of particle aggregates in the solidified structure. The phenomenon of encapsulation and solidification exists, which hinders the improvement of the micro-uniformity and microstructure of the composite material, especially as the proportion of high-entropy alloy components increases, the probability and area of ​​contact between a single particle and the aluminum alloy matrix further decrease. Mechanical stirring can only disperse the high-entropy alloy particles macroscopically, and the problems of poor dispersion and poor wetting of the local microscopic parts become more serious. The microscopic dispersion is not uniform, and there will be a large number of particle aggregates in the solidified structure. The phenomenon of encapsulation and solidification exists. In Figure 3 of the patent CN201510988188.X, a large number of black lamellar particles appear. Uniform dispersion is very conducive to the heterogeneous nucleation of the high-temperature aluminum alloy matrix, thereby greatly refining the grain

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