【摘要】 采用上引连铸-连续挤压技术制备Cu-0.88Cr-0.14Zr(质量分数)合金,并对挤压后的棒材进行不同制度的时效处理。利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、电子背散射技术(EBSD)等分析测试手段研究合金经不同工艺/制度处理后的组织与性能的变化。结果表明:上引连铸Cu-Cr-Zr合金棒坯在连续挤压过程中发生了剧烈的剪切变形和动态时效,晶粒明显细化,析出尺寸为15～20 nm的Cr相,与铸态相比,挤压态合金的导电率与硬度分别增加了28.6%IACS、49.6 HV。确定了挤压态合金杆材经(925℃,12 h)均匀化退火和(1000℃,1 h)固溶处理后的峰时效制度是(475℃, 3 h),此时基体中析出了平均晶粒尺寸为2.6 nm的Cr相,合金的导电率和硬度分别可达73%IACS、155 HV。更多还原

【Abstract】 Cu-0.88 Cr-0.14 Zr(mass fraction) alloy was prepared by up-drawn casting and continuous extrusion technology, and then the extruded bar was aged at different temperature for different time. The evolution of microstructure and properties of the alloy treated by different processes were investigated by scanning electron microscopy(SEM), transmission electron microscopy(TEM), electron back-scattered diffraction technology(EBSD), and so on. The results show that the Cu-Cr-Zr alloy casting rod billet has severe shear deformation and dynamic aging happened during continuous extrusion process, the grains are refined obviously and the Cr phases with size of 15-20 nm are precipitated. Compared to as-cast alloys, the electrical conductivity and hardness of the as-extruded alloy increase by 28.6% IACS and 49.6 HV, respectively. The peak aging of the extruded alloy after homogenization annealing at(925 ℃, 12 h) and solution treatment at(1000 ℃, 1 h) is determined to be(475 ℃,3 h). The Cr phase with average grain size of 2.68 nm is precipitated in the matrix after peak aging, and the electrical conductivity and hardness can reach 73% IACS and 155 HV, respectively.更多还原