【摘要】 对Cu-6%Ag(质量分数,下同)合金固溶后在350和450?C时效不同时间,观察了时效处理前后显微组织及测定了不同时效状态下合金的硬度和电导率。在350?C时效1h及450?C时效15min时,过饱和固溶体晶界附近即可明显析出次生Ag相并形成不连续析出区。随时效时间延长,不连续析出区域扩大及次生Ag相颗粒粗化。在350和450?C时效时,硬度达到峰值的时间分别为32及2h,电导率达到峰值的时间分别为128和8h。450?C时效的合金峰值硬度和峰值电导率高于在350?C时效的合金。在时效前期,较高温度的析出过程对提高合金硬度和电导率的效果比较明显,而在时效后期,较低温度析出过程对合金硬度和电导率的提高更为明显。更多还原

【Abstract】 As-cast Cu-6%Ag (mass fraction) alloy is solution treated and aged at 350 ℃ and 450 ℃ for different times. The microstructure is observed and the hardness and conductivity are measured for the alloy under different aging conditions. It is shown that the secondary Ag particles can be observed distinctly in the discontinuously precipitated cells adjacent to the grain boundaries in the supersaturated Cu matrix as the alloy is aged at 350 ℃ for 1 h or at 450 ℃ for 15 min. With the increase of aging time, the precipitated cells extend and the precipitates coarsen. The alloy shows the maximum hardness value when aged at 350 ℃ for 32 h or at 450?C for 2 h, and the maximum conductivity when aged at 350 ?C for 128 h or at 450 ℃ for 8 h. Generally, it is higher when aged at 450 ℃ than aged at 350 ℃. During the prior period of aging treatment, the precipitating process at a higher aging temperature is more significant to improve the hardness and conductivity, but the precipitating process at a lower aging temperature is more significant during the posterior period aging treatment.更多还原