A method for regulating and preparing in-situ binary nanoparticle-reinforced aluminum matrix composites

Abstract

The invention relates to an in-situ binary nanoparticle-reinforced aluminum-based composite material, in particular to a method for regulating and preparing the in-situ binary nanoparticle-reinforced aluminum-based composite material. The binary nanoparticle-reinforced aluminum-based composite material is prepared by the melt direct reaction method. The aluminum alloy smelting process adopts mechanical stirring and adds a rare earth master alloy. The mechanical stirring makes the melt generate a vortex, and quickly disperses the rare earth master alloy in the melt. Can make the melt temperature more uniform. During the reaction process, the acoustic-magnetic coupling field is applied, and the acoustic flow movement in two different directions ensures that the reinforced particles in the metal melt are evenly distributed throughout the melt, and the ultrasonic field is applied in the semi-solidified state to effectively inhibit the continued growth of the particles, so that Its distribution is more uniform, and the solid solution strengthening of the prepared composite material is carried out through heat treatment, so that the grain size is small, the nanoparticles are dispersed in the grain and on the grain boundary, and the interface between the particles and the matrix is ​​pure and pollution-free, and finally the in-situ aluminum matrix composites.

Description

technical field [0001] The invention relates to an in-situ binary nanoparticle-reinforced aluminum-based composite material, in particular to a method for regulating and preparing the in-situ binary nanoparticle-reinforced aluminum-based composite material. Background technique [0002] Due to its high elastic modulus, high strength and excellent corrosion resistance, particle reinforced aluminum matrix composites are widely used in aviation, aerospace, advanced weapons, automobile industry, precision instruments and other fields and other civil industries. These particle reinforcements play an important role in improving the performance of aluminum matrix composites. Generally speaking, when the content of reinforcing particles in the composite material is the same, the strengthening effect of nanoparticles is better than that of microparticles. In nanoparticle-reinforced aluminum matrix composites, the surface of the reinforcing particles is highly active, and the active i...

AI Technical Summary

Problems solved by technology

However, there are three disadvantages in the preparation process of in-situ binary composites: (1) The nanoparticle size is small, and the specific surface area effect is very obvious, which makes it easier for the particles to agglomerate and is difficult to disperse in the aluminum melt.

(2) The reaction temperature is high and the reaction time is long, which makes it difficult for the particles to reach the nanometer size

(3) The wettability of particles and matrix is ​​poor, and the yield of binary nanoparticles is low

[0003] At present, it is commonly used to introduce a single external field in the reaction process to regulate and improve its deficiencies. Chinese patent: CN102994814 A (date of invention: 2013.3.27, name of invention: a mixed particle reinforced wear-resistant aluminum matrix composite material generated in situ under a magnetic field and its Preparation method) proposes a preparation method of mixed particle reinforced wear-resistant aluminum matrix composites generated in situ under a single magnetic field. However, when a single magnetic field is applied, due to the insurmountable skin effect of the electromagnetic field in the metal melt, the magnetic field The action strength in the metal decays according to the exponential law, so the effective action depth of the magnetic field on the melt is limited; Chinese patent: CN 102943223 A (invention date: 2013.2.27, invention name: an aluminum matrix composite with high thermal conductivity under the ultrasonic field The preparation method of the material) provides a preparation method of the high thermal conductivity material under the ultrasonic field

However, when the metal melt is under the action of the ultrasonic field alone, the cavitation bubbles mainly exist near the horn, and the ultrasonic acoustic flow can only ensure that the cavitation bubbles move along the axial direction of the horn to the depth of the molten aluminum, which means Causes non-uniform distribution of cavitation bubbles throughout the metal melt

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