【摘要】 采用高能球磨法制备出了用于生产纳米晶稀土硬质合金的原料粉末。通过XRD、SEM和DTA等分析检测手段,研究了该纳米WC-Co-RE粉末的结构、形貌和相的变化。结果表明:高能球磨45h,可获得晶粒尺寸约为8.45nm的WC-Co-RE粉末;微量稀土的加入,有利于粉末晶粒的细化;在25～45h范围内,随着高能球磨时间的延长,粉末晶粒尺寸的减小趋势符合直线变化规律,且掺稀土粉末的晶粒尺寸比未掺稀土粉末的晶粒尺寸减小一半;高能球磨25h,粉末中Co相的X射线衍射峰消失。高能球磨WC-Co-RE粉末的DTA曲线在597℃出现了一个尖锐的放热峰。高能球磨WC-Co-RE粉末固结之后,所制得合金的晶粒细小且机械性能较好。更多还原

【Abstract】 The WC-Co-RE powder was prepared by high-performance ball milling.The structure,morphology and phase change of nano-crystalline powders were analyzed by means of XRD (x-ray diffraction),SEM (scanning electron microscope) and DTA (differential thermal analysis).The results showed that the nano-crystalline powder with grain size of 8.45 nm was obtained by 45-h ball milling and addition of trace rare earth was effective to diminish the grain size of the powder.The grain size of rare earth doped powder became two times smaller than that of the undoped powder,and the decrease trend of the grain size of the powder accord with linear regression equation after 25～45 h-ball milling.The XRD peak of Co phase disappeared after 25-h ball milling.A sharp peak of heat release at 597 ℃ was emerged in DTA curve.Upon the solidification,the powder exhibits fine grain size and good mechanical property.更多还原