Fabrication and Characterization of Bimodal Size Al2O3p Reinforced 7075 Aluminium Matrix Composites

Abstract

Bimodal sized (Nano and Micron) Al₂O₃ particle-reinforced 7075Al matrix composites were prepared by a new method called rotary stirring-injection process. The Al₂O₃ particles were injected into the molten 7075 alloy through the flows of inert argon gas, and the rotary stirring was used simultaneously. The effect of bimodal sized Al₂O₃ particles reinforcement with average size of 30 – 100 nm, 3 – 5 μm and volume fraction of 1 %, 4 % on microstructure, hardness and tribological properties of 7075 Al-based composite was investigated. Experimental results exhibited fine grains, well-dispersed bimodal sized Al₂O₃ particles and well-bonded interface between Al₂O₃ particles and 7075Al matrix. The hardness and wear behavior of the bimodal sized Al₂O_3p/7075 composites were significantly enhanced, being compared to the 7075Al matrix and the single sized Al₂O_3p/7075 composites.

DOI: http://dx.doi.org/10.5755/j01.ms.23.4.16956