Microstructure evolution and properties of Cu-20Ni-20Mn alloy during aging process  

时效过程中Cu-20Ni-20Mn合金的显微组织演变及性能（英文）

作　　者：谢伟滨[1] 王强松[1] 米绪军[1] 解国良[1] 刘冬梅[1] 高学成[1] 李洋[1] 

机构地区：[1]北京有色金属研究总院有色金属材料制备加工国家重点实验室,北京100088

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第10期3247-3251,共5页中国有色金属学报（英文版）

基　　金：Project(51401026)supported by the National Natural Science Foundation of China

摘　　要：The microstructure evolution and phase transformation of Cu-20Ni-20Mn（mass fraction,%） alloy at 450 °C were investigated by X-ray diffraction and transmission electron microscopy（TEM）.The variations of tensile strength,yield strength and hardness of this alloy during aging process were also analyzed.The results show that no significant variations of hardness and strength in the initial stage of aging,with a long incubation period,are observed at 450 °C.Subsequently,the ordered face-centered tetragonal（FCT） Ni Mn phase nucleates and grows up with prolonging the aging time.The hardness and tensile strength of the alloy increase up to their maximum values with increasing the ordered particle size,i.e.,the strength of the alloy reaches 942 MPa after being aged at 450°C for 40h.The main cause of the age-hardening is considered to be precipitation strengthening due to the ordered FCT-Ni Mn particles.通过X射线衍射(XRD)和透射电镜(TEM)研究Cu-20Ni-20Mn合金在450°C时效过程中的显微组织及相转变,并对时效后合金的抗拉强度、屈服强度和硬度进行分析。结果表明,时效开始阶段存在一个很长的孕育期,此时合金的强度和硬度没有明显变化。随着时效时间的延长,有序的面心四方结构(FCT)NiMn相在晶粒中形核并长大。随着有序FCT结构相尺寸的增加,合金硬度和强度提高并达到极大值。在450°C时效40h后合金强度达到942 MPa。由有序FCT结构NiMn相所产生的沉淀强化是合金主要的时效强化因素。

关 键 词：Cu-Ni-Mn alloy MICROSTRUCTURE mechanical properties ordered phase 

分 类 号：TG166.2[金属学及工艺—热处理]