C-ECAP冷轧和时效热处理制备微纳高强高导电性Cu0.9Cr0.1Zr合金

Micro-Nanostructured High-Strength and High-Conductivity Cu0.9Cr0.1Zr Alloy Prepared by C-ECAP, Cryogenic Rolling, and Aging

摘要:

Cu0.9Cr0.1Zr合金通过A路径的连续等通道转角挤压（C-ECAP）变形，随后进行液氮低温轧制（CR），并进行450 ℃的时效处理。利用电子背散射衍射仪、能量色散光谱仪、X射线衍射仪、扫描电子显微镜和透射电子显微镜对合金的微观结构、力学性能和导电性能进行了检测，分析了变形过程中织构演变机制及其对性能的影响。结果表明，在C-ECAP过程中，CuCrZr合金的微观结构中形成了定向剪切带，且微观结构的择优取向与轧制方向一致。变形后，随着变形量的增加，合金中析出相（主要是Cr）的含量增加，并伴随着微纳结构纤维状组织的出现。经过3次C-ECAP挤压、75%冷轧变形以及在450 ℃下时效2 h后，合金的抗拉伸强度、硬度和电导率分别达到538 MPa、168 HV和80%IACS。低温轧制、时效热处理以及再结晶织构的形成均有利于提高合金的电导率。

Abstract:

The Cu0.9Cr0.1Zr alloy was deformed through continuous equal channel angular pressing (C-ECAP) through Route A, followed by liquid nitrogen cryogenic rolling (CR) and aging treated at 450 °C. The microstructure, mechanical properties, and conductivity of the alloy were detected by electron back-scattered diffractometer, energy dispersive spectroscope, X-ray diffractometer, scanning electron microscope, and transmission electron microscope. The evolution mechanism of the texture during the deformation process and its influence on mechanical properties were analyzed. The results show that directional shear bands form in the CuCrZr alloy during the C-ECAP process, and the preferred orientation of the microstructure is consistent with the rolling direction. After deformation, the number of precipitated phases (mainly Cr) increases with the prolongation of aging time, accompanied by the appearance of micro-nanostructured fibrous structure in the alloy. After C-ECAP for three passes, 75% CR deformation, and aging at 450 °C for 2 h, the tensile strength, microhardness, and conductivity reach 538 MPa, 168 HV, and 80%IACS, respectively. CR, aging heat treatment, and formation of recrystallization texture are all conducive to the improvement of conductivity.