高能机械研磨纳米结构WC-Co复合粉末的研究

Study on Nanostructured WCCo Composite Powders Made by Mechanical Milling

采用高能机械研磨制备纳米结构ＷＣＣｏ复合粉末，研磨后的纳米结构ＷＣＣｏ复合粉末采用Ｘ射线衍射（ＸＲＤ），高分辨透射电镜（ＨＲＴＥＭ），Ｘ射线能谱仪（ＥＤＳ）分析其微观结构（包括晶粒尺寸，应变，Ｃｏ的分布和晶格缺陷）。研究发现经过高能机械研磨，ＷＣ的晶粒尺寸能降低到１０ｎｍ以下，纳米尺度的ＷＣ晶粒被Ｃｏ薄层覆盖和分离，ＷＣ晶粒的形貌为近似球形，并且ＷＣ晶粒中产生了大量的晶格缺陷。

Nanostructured WCCo composite powders were prepared by highenergy mechanical milling. The microstructure of asmilled WCCo composite powders (including grain size, lattice strain, Co distribution and lattice defects) was investigated by Xray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and energy dispersive Xray spectroscopy (EDS). Nanostructured WC covered and separated by cobalt thin layers with average grain size less than 10 nm was obtained by high energy mechanical milling. The morphology of WC grains is almost spherical. Highenergy mechanical milling could also bring about a large number of lattice defects in WC grains.