摘要
The Cu-Cr-Zr alloys were aged at different temperatures for different time with different current densities. The results show that both the electrical conductivity and hardness are greatly improved after being aged with current at a proper temperature. The electrical conductivity increases approximately linearly with increasing current density while the hardness remains constant. The microstructure observation reveals that a much higher density of dislocations and nanosized Cr precipitates appear after the imposition of current, which contributes to the higher electrical conductivity and hardness. The mechanism is related with three factors: 1) Joule heating due to the current, 2) migration of mass electrons, 3) solute atoms, vacancies, and dislocations promoted by electron wind force.
在不同温度和电流密度下对Cu-Cr-Zr合金进行不同时间的时效处理,发现在合适的时效温度下施加电流,可以同时提高合金时效后的电导率和硬度。随着电流密度的增加,电导率呈线性增长,但硬度保持不变。显微组织观察表明,施加电流时效后,组织中出现了大量的位错和纳米级铬析出物,这是提高电导率和硬度的原因。电流作用机理与焦耳热、大量电子的迁移及因电子风力而提高的溶质原子、空位和位错的扩散能力有关。
基金
Project (2009AA03Z109) supported by the National High-tech Research and Development Program of China
Project (09zz98) supported by Key Research and Innovation Program from Shanghai Municipal Education Commission, China
Projects (09dz1206401, 09dz1206402) supported by Key Project from Science and Technology Commission of Shanghai Municipality, China