【作者】 周倩；

【导师】 李雷；

【作者基本信息】 河南理工大学 ， 材料加工工程， 2009， 硕士

【摘要】 采用真空熔炼法制备Cu-0.85Cr-0.1Zr、Cu-0.85Cr-0.1Zr-0.1Ag两种合金坯料,利用光学显微镜、扫描电子显微镜及能谱分析仪、透射电子显微电镜、电阻测试仪、万能实验机和显微硬度计等分析手段,研究添加微量Ag、不同的时效时间、塑性变形处理工艺对Cu-Cr-Zr系合金组织性能的影响。对Cu-0.85Cr-0.1Zr、Cu-0.85Cr-0.1Zr-0.1Ag两种合金,采用热挤压—960℃/1h固溶、水淬—450℃/0.5~2h时效—冷拉拔等工艺处理后,结果发现:在时效时间为90min,形变量为75%时,Cu-0.85Cr-0.1Zr合金的电导率为50%IACS,抗拉强度为510MPa。而Cu-0.85Cr-0.1Zr-0.1Ag合金,在时效时间为75min,形变量为75%时,其电导率为81.15%IACS,抗拉强度为466MPa。可见添加微量Ag提高了Cu-Cr-Zr系合金的综合性能。研究了Cu-0.85Cr-0.1Zr、Cu-0.85Cr-0.1Zr-0.1Ag两种合金的时效分解和第二相的析出过程。根据相变动力学Avrami经验方程,得到了两种合金时效分解的相变动力学方程及相应的电导率方程。通过对Cu-0.85Cr-0.1Zr、Cu-0.85Cr-0.1Zr-0.1Ag两种合金的固溶强化、沉淀强化、加工硬化等强化方式的研究,发现冷塑性变形引起的加工硬化是提高合金力学性能的主要方法,其强化相是富Cr相。观察与表征富Cr析出相的形貌特征及分布规律,并对其不同处理态下的变化规律进行了总结,结果发现:随着时效时间的延长,富Cr析出相不断析出,并在2h后有粗化趋势;随着形变量的加大,富Cr析出相在垂直加工方向上破碎呈颗粒状,在加工方向上呈纤维状。更多还原

【Abstract】 Cu-0.85Cr-0.1Zr and Cu-0.85Cr-0.1Zr-0.1Ag alloy were fabricated by vacuum melting method. Using light microscope、SEM and energy spectrum analysis、TEM、resistance testing instrument、mechanical properties testing machine and microhardness instrument,The effect of the additional of Ag、different aging time、plastic deformation technology upon the microstructures and properties were studied.Cu-0.85Cr-0.1Zr and Cu-0.85Cr-0.1Zr-0.1Ag were processed by the same process such as hot extrusion-960℃/ 1h solution hardening-450℃/ 0.5h~2h aging-cold plastic deformation. Resultes showed that better comprehensive performances for Cu-0.85Cr- 0.1Zr will display if the aging time is 90min and plastic deformation degree is 50%, the conductivity and tensile strength can arrive at 50%IACS and 510MPa. While Cu-0.85Cr-0.1Zr-0.1Ag alloy will display better comprehensive performances, the conductivity is 81.15%IACS and tensile strength is 466MPa, if the aging time is 75min and plastic deformation degree is 75%.The precipitation course of supersaturated Cu-0.85Cr-0.1Zr and Cu-0.85Cr-0.1Zr -0.1Ag alloys were investigated and the behavior of second-phases precipitation was discussed. The Avrami dynamic equations about two kinds of Cu-Cr-Zr alloy aging course were establish, and the conductivity equations of above two kinds of Cu-Cr-Zr alloy were created according to the Avrami empirical equations.Various strengthening models of Cu-0.85Cr-0.1Zr and Cu-0.85Cr-0.1Zr-0.1Ag alloy were analyzed, including solution strengthening、work-hardening、fiber strengthening、precipitation strengtheing and so on. Work-hardening effect from the cold plastic deformation after aging treatment was a key method to improve mechanical property of Cu-Cr-Zr, the main hardening phases should be Cr-rich particles.The morphology of Cr-rich phase were observed and characterized, and the distribution characteristics were generalized. The evolution laws of Cr-rich phase at different treatment condition were studied: with extension of aging time, Cr-rich phase precipitated continuously, and had tendency to grow up after aging 2h; with extension of sizing reduction, Cr-rich phase were like grainess on the transverse direction, and nemaline on the rolling direction.更多还原