Influence of flame rectification on mechanical properties of AlZnMg alloy

The mechanical properties of AlZnMg alloy after flame rectification at 300 °C and 350 °C for different numbers of times were investigated, and the mechanism of precipitation transformation in AlZnMg alloy was interpreted. The results show that the matrix precipitates (MPs) coarsened or diminished with increasing the number of times in flame rectification at 300 °C, and meanwhile the grain boundary precipitates (GBPs) dissolved. However, the matrix precipitates largely dissolved into the matrix and the grain boundary precipitates changed complicatedly with increasing the number of times in flame rectification at 350 °C. The difference of microstructure evolution after flame rectification at two temperatures led to significant differences in mechanical properties of AlZnMg alloy. To conclude, the mechanical properties of AlZnMg alloy achieved optimal after flame rectification at 350 °C for two times.