机械合金化诱导难互溶系Cu-Cr合金固溶度扩展的研究

Extension Solid Solubility of Immiscible Cu-Cr Alloy System Induced by Mechanical Alloying

采用机械合金化工艺制备Cu-4%Cr和Cu-7%Cr(原子分数)二元合金粉末,利用XRD,SEM和TEM研究机械合金化过程中粉末的微观形貌和显微组织结构,测量了不同球磨时间粉末的氧含量以及显微硬度。结果表明:在一定的球磨时间内,Cu-Cr合金粉末随着高能球磨的进行,晶粒逐渐细化至纳米尺寸,晶格畸变增加,但进一步球磨会导致铜的晶格常数有所增加,畸变降低。实验证明,在固态下几乎不互溶的Cu-Cr合金,经球磨40 h的机械合金化,Cr在Cu中的固溶度明显提高。

Cu-4%Cr and Cu-7%Cr（atomic fraction） binary powders were synthesized by mechanical alloying.XRD,SEM and TEM were used to investigate the microstructure of the powders during ball milling process,and the oxygen content and microhardness of the powders for different balling time were measured.The results showed that the grain size of the Cu-Cr alloy powders gradually changed to nanometer scale with the increasing of milling time and the lattice strain increased.After further milling,lattice parameter for copper increased,and the crystal lattice distortion reduced.The results also indicated that,after high energy ball milling for 40 h the solid solubility of Cr in Cu could be evidently extended,even though the equilibrium solid solubility of Cr in Cu was little,as the Cu-Cr alloy was immiscible system.