Effect of sintering temperature and heating mode on consolidation of Al�??7Zn�??2.5Mg�??1Cu aluminum alloy

[摘要] Densification behaviour, phase transformation, microstructural evolution and hardness values of microwave sintered Alâ€�??7Znâ€�??2.5Mgâ€�??1Cu (7775) aluminum alloy were investigated and compared with conventionally sintered samples. Microwave sintering was performed in 2.45 GHz multimode microwave furnace at temperatures ranging from 570â€�??630 °C. Microwave sintering at a heating rate of as high as 22°C/min resulted in ∼55% reduction of processing time as compared to conventional sintering. A lower sintered density observed in the case of microwave processed samples was attributed to the inhomogeneity in microstructure and phase distribution. The X-ray diffraction results of conventionally sintered samples showed the presence of MgZn₂, Mg₂Zn₁₁ and CuMgAl₂, while only MgZn₂ and CuMgAl₂ phases were found in the case of microwave sintered samples and in lesser amount. Higher hardness and high standard deviation values were noticed for microwave sintered samples as compared to conventional counterparts.

[学科分类] 材料工程

[关键词] Aluminum alloys;microwave sintering;densification.