论文部分内容阅读
往Al-Zn-Mg合金中添加微量钛(0.04％),以便确定钛对这种合金的显微组织和时效特性的影响。发现钛能延迟析出动力学,并且在空气淬火时,能阻止溶质在晶界上偏析。低于G.P.区溶解温度,合金的硬化是由于形成位错环和G.P.区。超过G.P.区的溶解温度,硬化仅仅是由于形成析出物。这些结果用钛能降低溶质原子—空位集团的形成,以及引起锌和镁迁移率降低来解释。
A trace amount of titanium (0.04%) was added to the Al-Zn-Mg alloy in order to determine the effect of titanium on the microstructure and aging properties of this alloy. Titanium was found to retard the precipitation kinetics and prevent the solute segregation at the grain boundaries during air quenching. Below the G.P. zone dissolution temperature, the alloy is hardened due to the formation of dislocation loops and G.P. zones. Above the dissolution temperature of the G.P. zone, hardening is only due to the formation of precipitates. These results are explained by the fact that titanium can reduce the formation of solute atom-vacancy groups and cause a decrease in the mobility of zinc and magnesium.