Method for preparing nano-aluminum-nitride reinforced aluminum-based composite semi-solid slurry based on ultrasonic and mechanical vibration combination

Abstract

The invention relates to a method for preparing nano-aluminum-nitride reinforced aluminum-based composite semi-solid slurry based on ultrasonic and mechanical vibration combination. The method comprises the steps: firstly, mixing nano aluminum nitride particles and aluminum powder according to the mass ratio of (1: 1) to (2: 3), and carrying out ball milling for 50-60 hours at the revolving speed of 60-70rpm so as to obtain mixed powder; putting the mixed powder into a crucible, and heating to the temperature of 660-670 DEG C; cooling with air, crushing and sieving; melting aluminum alloy in the crucible so as to obtain aluminum alloy melt, adding the sieved mixed powder into the aluminum alloy melt at the temperature of 700-750 DEG C in 5-10 minutes in accordance with that the addition amount of the nano aluminum nitride particles is 1-4wt.% of the amount of the aluminum alloy melt, meanwhile, introducing high-energy ultrasonic sound of 20KHz and 1-3KW, and then, continuing to carry out ultrasonic treatment for 5-10 minutes; cooling the melt to an alloy semi-solid temperature range at the cooling speed of 5-15 DEG C / min, and applying mechanical vibration treatment at the power of 1.5KW, the frequency of 400-600Hz and the amplitude of vibration of 0.5-1.5mm. According to aluminum-based nano composite material tissue prepared by the method, a newborn alpha-Al phase is fine and is uniform in distribution, nano aluminum nitride particles are uniform in distribution and are free from an agglomeration phenomenon, and the method is low in process cost and convenient in operation and is simple, safe and reliable.

Description

technical field

[0001] The invention belongs to the field of metal material preparation, in particular to a method for preparing semi-solid slurry of aluminum-based composite materials. Background technique

[0002] During the forming process, the semi-solid alloy has stable mold filling, low thermal stress, less shrinkage cavity and shrinkage defects, and a net near-formation. Particle-reinforced aluminum matrix composites have many advantages such as specific strength, high specific stiffness, high wear resistance, and high vibration damping. Aluminum nitride particles are an ideal reinforcement phase because of their good physical, chemical, mechanical and thermal properties, and have attracted the attention of many scholars. Micron particles can improve the yield strength and ultimate compressive strength of the matrix, but make the ductility of the matrix worse. Nanoparticles can significantly improve the elastic modulus, yield strength, wear resistance and high tempe...

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