Synthesis and characterization of nanocrystalline Ni produced by cryomilling in liquid nitrogen  

作　　者：YANG Bin FAN Jianzhong HAO Bin TIAN Xiaofeng CHENG Junsheng ZHANG Jishan 

机构地区：[1]State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China [2]International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang 110016, China [3]National Engineering and Technology Research Center for Nonferrous Metals Composites, General Research Institute for Nonferrous Metals, Beijing 100088, China

出　　处：《Rare Metals》2007年第2期147-151,共5页稀有金属（英文版）

基　　金：This project was financially supported by the High Technical Research and Development Programme of China (No. 2002AA302502).

摘　　要：NanocrystaUine Ni powders were successfully fabricated by mechanically milling at cryogenic temperature （cryomilling） with 1 wt.%Y2O3 particles. The experimental results have shown that the Ni grain size is reduced to 25 nm after 2 h of cryomilling in the presence of the Y2O3 particles. The cryomiUed Ni/Y2O3 powders can maintain their nanocrystalline structure up to 900℃, or 62% of the melting point of Ni. A bulk nanocrystalline Ni/Y2O3 material with a thermally stable grain size of approximately 100 nm was produced by cryomilling, cold isostatic pressing, followed by hot isostatic pressing. The microhardness of bulk nanocrystalline Ni/1wt.%Y2O3 is 315 DPH, which is two times as high as that of conventional Ni.NanocrystaUine Ni powders were successfully fabricated by mechanically milling at cryogenic temperature （cryomilling） with 1 wt.%Y2O3 particles. The experimental results have shown that the Ni grain size is reduced to 25 nm after 2 h of cryomilling in the presence of the Y2O3 particles. The cryomiUed Ni/Y2O3 powders can maintain their nanocrystalline structure up to 900℃, or 62% of the melting point of Ni. A bulk nanocrystalline Ni/Y2O3 material with a thermally stable grain size of approximately 100 nm was produced by cryomilling, cold isostatic pressing, followed by hot isostatic pressing. The microhardness of bulk nanocrystalline Ni/1wt.%Y2O3 is 315 DPH, which is two times as high as that of conventional Ni.

关 键 词：NANOCRYSTALLINE mechanical milling NICKEL CHARACTERIZATION 

分 类 号：TB44[一般工业技术] TF123.111[冶金工程—粉末冶金]