摘要
采用温度记录系统、组织观察、力学性能测试、电导率测试和DSC热分析研究7050高强铝合金固溶过程中的温度变化,确定合理的固溶热处理制度。采用了2种不同尺寸规格的试样进行试验。研究表明,在本试验条件下的固溶热处理过程中,大尺寸试样固溶温度相对较低,固溶时间较短,导致合金中强化析出相的体积分数减少。对于尺寸为25mm×25mm×2.5mm和70mm×60mm×20mm的试样,合理的固溶热处理制度分别为(480℃,30min)和(480℃,90min)。小尺寸试样中的GP区和η′相密度大于大尺寸试样中相应的密度,这与合金性能测试的结果一致。
Temperature variation and solution treatment of high strength aluminum alloy were investigated with temperature data acquisition system,microstructural observation,mechanical properties test,electrical conductivity measurement and differential scanning calorimetry(DSC) analysis.Specimens with two dimensions were employed in the experiment.The results indicate that the specimens with large size undergo low solution temperature and short time,giving rise to the reduction of hardening precipitates.The optimized solution treatments for specimens with dimensions of 25 mm×25 mm×2.5 mm and 70 mm×60 mm×20 mm are(480 ℃,30 min) and(480 ℃,90 min),respectively.The densities of GP zones and η' phases of the small specimen are higher than those of the large specimen,which is consistent with the properties of the alloys.
基金
Project(2010DFB50340) supported by the International Technical Cooperation Project
Project(50904010) supported by the National Natural Science Foundation of China
关键词
铝合金
试样尺寸
固溶处理
升温速率
强化析出相
aluminum alloy
specimen size
solution treatment
heating rate
hardening precipitate