Influence of Solution Heat Treatment on Microstructures of Semisolid Cast 7075 Aluminium Alloy
Influence of temperature and time of solution heat treatment on the microstructures of rheo-casting 7075 aluminium alloy produced by a novel technique, the Gas Induced Semi Solid (GISS) technique, had been investigated in this study. The microstructure of the as-cast specimens mainly consisted of matrix-α (Al) and grain boundary (GB)-eutectic phase (α-Al + Mg(Zn,Cu,Al)2). After solution heat treatment at 480 °C for 1 h, MgZn2 phase at the grain boundary was observed to have dissolved and coarse black particles of Mg2Si were observed to form in the matrix. In comparison, when solutionizing temperature of 450 °C was applied, it took 4 h of solution treatment time in order to dissolve the same portion of GB phase and MgZn2 phase, and coarse black particles of Mg2Si were found to form in the 8 h solution treated sample.
Zhijiu Ai, Xiaodong Zhang, Yun-Hae Kim and Prasad Yarlagadda
N. Mahathaninwong et al., "Influence of Solution Heat Treatment on Microstructures of Semisolid Cast 7075 Aluminium Alloy", Advanced Materials Research, Vol. 339, pp. 371-374, 2011