摘要
The effect of equal-channel angular pressing(ECAP)processing at room temperature and 300℃on the distribution of the second phase particles and its influence on hardness and electrical conductivity of the commercial Cu-0.81Cr-0.07Zr alloy were investigated.Microstructural characterization indicated that the area fraction of coarse Cr-rich particles decreased after ECAP processing.This reduction was attributed to the Cr dissolution induced by plastic deformation.The electrical conductivity of the alloy decreased by 12%after 4 ECAP passes at room temperature due to the increase of electrons scattering caused by higher Cr content in solid solution and higher density of defects in the matrix.These results were supported by the reduction of the Cu lattice parameter and by the exothermic reactions,during differential scanning calorimetry(DSC)analysis,observed only in the samples subjected to ECAP processing.Aging heat treatment after ECAP processing promoted an additional hardening effect and the complete recuperation of the electrical conductivity,caused by the re-precipitation of the partially dissolved particles.The better combination of hardness(191 HV)and electrical conductivity(83.5%(IACS))was obtained after 4 ECAP passes at room temperature and subsequent aging at 380℃for 1 h.
研究在室温和300℃下等径角挤压(ECAP)对Cu-0.81Cr-0.07Zr合金中第二相分布的影响,及其对硬度和电导率的影响。显微组织表征表明,经ECAP后,粗大的富Cr颗粒面积分数减小,这是由于塑性变形导致Cr的溶解。在室温下进行4道次ECAP后,由于固溶体中较高的Cr含量和基体中较高的缺陷密度导致电子散射的增加,合金的电导率下降了12%。仅在ECAP样品中观察到的Cu晶格常数的减小和差示扫描量热分析(DSC)过程中发生的放热反应证实了这些结果。经ECAP后的时效热处理促进额外的硬化效果和导电性的完全恢复,这是由于部分溶解颗粒的再沉淀造成的。在室温下进行4道次ECAP,然后在380℃时效处理1 h的合金具有更高的硬度(191 HV)和电导率(83.5%(IACS))。
作者简介
Corresponding author:Filipe CALDATTO DALAN,E-mail:caldatto.filipe@gmail.com。
