纯铜梯度纳米化表面硬质膜的微观结构演化与力学性能研究  

Study on Microstructure Evolution and Mechanical Properties of Hard Film on the Gradient Nanocrystallization Surface of Pure Copper

作　　者：吴嘉楠 张柯[1] 刘平[1] 陈小红[1] WU Jianan;ZHANG Ke;LIU Ping;CHEN Xiaohong(School of Materials Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学材料科学与工程学院,上海200093

出　　处：《有色金属材料与工程》2020年第6期16-23,共8页Nonferrous Metal Materials and Engineering

基　　金：国家重点研发计划项目(2017YFB0306405)。

摘　　要：利用磁控溅射法在纯铜的表面沉积TiN硬质膜,然后对镀膜后的试样进行表面机械滚压处理(surface mechanical rolling treatment,SMRT),在其表层形成梯度纳米结构层。采用金相显微镜(optical microscopy,OM)、扫描电子显微镜(scanning electron microscope,SEM)等对试样的表面形貌和显微结构进行表征,研究梯度纳米结构层的强化方式和组织演化规律。通过改变SMRT工艺的参数,在试样的表面制备出不同厚度的梯度纳米结构层。研究发现:随着下压量的增加,表面的梯度纳米层随之变厚,硬质膜颗粒与纯铜基体的结合更紧密;表面梯度纳米化影响了硬质膜的组织结构;颗粒被碾入纯铜表层中,提高了试样的综合力学性能,屈服强度最高增加了73%,同时其塑性降低很少;试样表面的硬度最大可以达到约1.6 GPa,并且沿厚度方向从表层到芯部的硬度呈梯度分布。TiN hard film was deposited on the surface of pure copper by magnetron sputtering method,and then the surface mechanical rolling treatment(SMRT)was carried out on the coated sample to form gradient nanostructure layer on the surface.The surface morphology and microstructure were characterized by optical microscopy(OM),scanning electron microscope(SEM),and so on,in order to study the strengthening mode and microstructure evolution of gradient nanostructure layer.By changing the parameters of SMRT process,gradient nanostructure layers with different thickness were prepared on the surface of the samples.The study finds that as the amount of depression increases,the gradient nanostructure layer on the surface becomes thicker,and the hard film particles are more closely combined with the pure copper matrix.The microstructure of the hard film is affected by the surface gradient nanocrystallization.The particles are crushed into the pure copper surface to improve the comprehensive mechanical properties of the sample.The yield strength is increased by up to 73%,while its plasticity is reduced very little.The hardness of the sample surface can reach up to about 1.6 GPa,and the hardness from the surface layer to the core along the thickness direction shows a gradient distribution.

关 键 词：表面机械滚压处理 硬质膜 梯度纳米结构 演化规律 

分 类 号：TG174[金属学及工艺—金属表面处理]