Papers by Author: D. Zhang

Abstract: An enhanced nucleation heat treatment process was employed to refine the grain structure of 7075Al/ 7wt.% SiCp metal matrix composite material. The grain structure of the metal matrix composite was investigated. The resulting microstructures were compared. It was found that a fine grained microstructure developed after the rapid heat treatment process. An increase in hardness was achieved, with hardness increasing from 129 HV in the cold extruded state to 137 – 153 HV after the heat treatment process.

Abstract: Particulate reinforced 10 vol.% (TiB+TiC)/Ti-6Al-4V metal matrix composites (MMCs) were produced by in-situ synthesis using vacuum arc re-melting process, and the mechanical properties of the metal matrix composites were assessed by the small punch testing (SPT). Mechanical properties of the in-situ synthesized Ti MMCs were studied and compared with the Ti base alloy. From the test data, the fracture properties and equivalent fracture strain of the test materials were characterised. The fracture mechanism of the test samples was examined using scanning electron microscopy.

Abstract: Particulate reinforced Ti based metal matrix composites (MMCs) were made by in-situ synthesis using vacuum arc re-melting process. The microstructure of the Ti-6Al-4V base alloy and 10 vol.% (TiB+TiC)/Ti-6Al-4V metal matrix composites was examined. The particulate reinforcements were analysed and identified TiB and TiC particles. The particle distribution was analysed using the quadrat method over 1620 quadrats. A homogeneous particle distribution was found to establish in the composites. The experimental distribution of the reinforcements agreed well with the theoretical Poisson distribution. A skew factor, which characterizes the degree of asymmetry of a statistical distribution, of 1.108 was determined for the particle distribution in the material.