机械合金化制备Ni-W(B)非晶-纳米晶的粉末特性

利用机械合金化(MA)制备了Ni-20.7W和Ni-17.9W-27B(at%)非晶-纳米晶粉末,分别采用扫描电镜(SEM)和X射线衍射(XRD)仪分析了不同球磨时间粉末的微观形貌和结构参数,探讨了B的添加对非晶化过程的影响。研究结果表明:MA过程中,Ni-20.7W样品没有明显发生非晶化,而Ni-17.9W-27B样品在40 h时发生了非晶化,说明B提高了Ni-W合金体系的非晶化形成能力;非晶化过程为W/B首先固溶于Ni中生成Ni(W,B)过饱和固溶体,然后转变为非晶;Ni-20.7W样品球磨30 h后Ni的晶粒尺寸为32.9 nm,晶格畸变为0.48%,而Ni-17.9W-27B样品球磨10 h后的晶粒尺寸为9 nm,晶格畸变为0.62%。

Microstructure characteristics and preparation of Ni-W(B) Amorphous-Nanocrystalline powders by Mechanically alloyed method

Amorphous-Nanocrystalline powders of Ni79.3W20.7 and Ni55.1W17.9B27 were prepared by mechanically alloyed method. The microstructure characteristics and structure parameters of powders for different milling times were studied by SEM and XRD, respectively, and the effect of B additive on the progress of amorphization was analyzed. The research results showed that, during MA, the Ni79.3W20.7 was not amorphized, while the Ni55.1W17.9B27 was amorphized after 80 hours. It suggested that the addition of B improved the glass-forming ability of the Ni-W alloy systems. The amorphization progress was that W/B first dissolved in Ni to form Ni(W, B) supersaturated solid solution during MA, and then amorphization of Ni(W, B) supersaturated solid solution occurred. Furthermore, grain size and internal strain of Ni in Ni79.3W20.7 powder were 32.9nm and 0.48 pct after 30 hours of milling, whereas those of Ni55.1W17.9B27 powder were 9nm and 0.62 pct after 10 hours of milling.