高能球磨制备Cu-Cr纳米晶粉末  

Cu-Cr nanocrystalline powder prepared by high-energy ball milling

作　　者：史昆玉[1] 沈涛[1] 陈春浩[1] 薛丽红[1] 严有为[1] 

机构地区：[1]华中科技大学材料成形及模具技术国家重点实验室,武汉430074

出　　处：《粉末冶金材料科学与工程》2013年第4期532-538,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：阿尔斯通电网资助项目

摘　　要：采用高能球磨法制备Cu-50%Cr(质量分数)纳米晶复合粉末。利用X射线衍射(XRD)、差示扫描量热法(DSC)、扫描电镜(SEM)、能谱分析(EDS)以及透射电镜(TEM)等方法,研究球磨时间和过程控制剂(PCA)对复合粉末的晶粒尺寸、微观组织与形貌的影响,采用热力学模型对该体系的固溶度进行计算和分析。结果表明:当PCA含量为0时,晶粒的细化效果最好,但产率较低;当PCA的添加量过多,晶粒的细化效果不明显;在本实验条件下,PCA的最佳质量分数添加量为5%。随球磨时间的延长,晶粒逐渐细化,晶格畸变先增大后减小;经60 h球磨,可获得Cu和Cr两相均匀分布的复合粉末,其平均晶粒尺寸为10 nm左右,Cr在Cu中的固溶度显著提高,热力学计算结果表明其固溶度为7%(质量分数)。Nanocrystalline Cu-50%Cr composite powders were prepared by high-energy ball milling. Effects of ball milling time and process control agent （PCA） on the grain size, microstructure and morphology of the composite powders were studied using X-ray diffraction （XRD）, differential scanning calorimetry （DSC）, scanning electron microscopy （SEM）, energy dispersive spectrometer （EDS） and transmission electron microscopy （TEM）. A thermodynamic model was also applied to predict the change in the solubility limit of the Cu-Cr system. The results show that the powders are refined at a highest rate without the addition of PCA, but the powder yield is lower. However the excess of PCA would weaken the grain refinement. On this conditions, the optimum addition of PCA is 5% （mass fraction）. With increasing milling time, the grain size of the powders decreases gradually, while the micro-strain increases firstly then decreases correspondingly. After milling for 60 h, the nanocrystalline Cu-50%Cr composite powders with homogeneous distribution of Cu and Cr phase are achieved with average grain size of about 10 nm and the solid solubility of Cr in Cu is extended largely up to 7%.

关 键 词：CU-CR合金 高能球磨 纳米晶材料 固溶度 

分 类 号：TG146.1[一般工业技术—材料科学与工程] TF123.71[金属学及工艺—金属材料]