Method for preparing nano-alumina reinforced aluminum-based composite semi-solid slurry

Abstract

The invention relates to a method for preparing nano-alumina reinforced aluminum-based composite semi-solid slurry. The method comprises the steps: firstly, carrying out ultrasonic treatment on nano alumina for 20-25 minutes in anhydrous ethanol, removing anhydrous ethanol, drying, calcining for 3-4 hours at the temperature of 550-600 DEG C, adding magnesium powder according to the mass ratio of (1: 7) to (5: 3), and carrying out ball milling for 30-60 minutes at the revolving speed of 100-150rpm so as to obtain mixed powder; melting aluminum alloy in a clay crucible so as to obtain aluminum alloy melt, adding the mixed powder into the aluminum alloy melt at the speed of 0.2-0.3g / min at the temperature of 700-800 DEG C in accordance with that the addition amount of the nano alumina is 0.5-2.5wt.% of the amount of the aluminum alloy melt, meanwhile, treating with high-energy ultrasonic sound of 5-10KHz and 1,000W, and then, continuing to treat with ultrasonic sound of 20KHz and 800-1,000W for 5-20 minutes; pouring the melt in the crucible of 600-650 DEG C, controlling the temperature to 700-720 DEG C, treating by applying ultrasonic sound of 20KHz and 600-1,000W, and cooling the alloy melt to a semi-solid temperature range at the cooling speed of 5-15 DEG C / min. 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 alumina 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, and high wear resistance. Alumina (Al 2 o 3 ) is an ideal reinforcing phase because of its good physical, chemical, mechanical and thermal properties, and has 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 temperature creep of the matrix while ma...

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