Microstructure and properties of in situ Ti–Al intermetallic compound-reinforced Al matrix composites with dispersive distribution of core–shell-like structure

Abstract

Recently, Ti–Al intermetallic compound-reinforced Al matrix composites have attracted increasing attention because of their high specific modulus, strength, and thermal stability. In this study, blended powders of Ti and Al were ball milled and fabricated to in situ Ti–Al intermetallic compound-reinforced Al matrix composites by cold-pressing and hot-pressing sintering. The microstructures and component of core–shell-like structure in reinforcement were observed and analyzed. Material properties including hardness, density, and compression performance were tested and analyzed according to experimental processes. The results indicate that the time point of compression in hot-pressing sintering is crucial to obtain the closed core–shell-like structures. Based on the orthogonal experimental data, entropy methods and technique for order preference by similarity to ideal solution were combined to select the process parameters (ratio of Ti and Al, milling time, sintering temperature, holding time, and compaction pressure) for the best comprehensive performance of Vickers hardness and compressive yield strength.