直流电对7B04铝合金固溶与时效组织和性能的影响

Effects of direct current on the microstructures and properties of 7B04 aluminum alloy during solid solution and artificial ageing

摘要:

本文采用拉伸试验、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等手段,研究了7B04铝合金在施加和不施加直流电条件下,经470℃固溶和100-140℃时效处理后的组织和力学性能。与传统的T6处理(470 oC/30 min+120 oC/24h)相比,固溶和/或时效处理时施加500A的电流,可显著提高GPII区的析出密度,进而提高峰时效状态下的拉伸强度和延伸率。固溶过程中施加直流电可将随后时效合金达到峰值强度的时间明显缩短12h。

Abstract:

The microstructures and mechanical properties of 7B04 aluminum alloy solid solution at 470oC and aged at 100-140 oC without and with electric current were investigated by tensile test, scanning electron microscope (SEM) and transmission electron microscope (TEM). Compared with the traditional T6 treatment (470 oC/30min+120 oC/24h), applying electric current of 500A during solid solution and/or ageing treatment can increase both the tensile strengths and elongation at the age-peak state, due to the significant increase of the precipitation density of Guinier- Preston II (GPII) zones. Applying electric current during solid solution can significantly reduce the time to the peak strength by 12h in the subsequent ageing alloy