机械合金化-射频等离子球化制备WMoTaNbV难熔高熵球形粉末

Preparation of WMoTaNbV refractory high-entropy spherical powder by mechanical alloying-radio frequency plasma spheroidization

摘要:

本研究以单质元素粉末为原料，采用机械合金化和射频等离子体球化制备WMoTaNbV难熔高熵合金球形粉末。重点研究了球磨时间和射频等离子体球化过程对粉末物相、形貌、粒度和杂质含量的影响规律，并使用X射线衍射仪、扫描电镜、透射电镜、碳硫仪、氧氮氢仪和激光粒度分析仪等对粉末性能进行分析表征。结果表明：随着球磨时间的延长，低熔点元素逐渐向高熔点元素固溶。当球磨时间为14 h时，可以形成单一BCC相结构的难熔高熵合金粉末，粒径随球磨时间的延长逐渐细化，杂质含量随着球磨时间延长而增加。选取球磨2h的粉末进行射频等离子球化，球化后的粉末中位粒径为66.0μm，氧碳含量分别是540 ppm和210 ppm，粉末流动性显著提高至8.4s·(50 g)-1，振实密度达到8.80 g·cm-3.

Abstract:

WMoTaNbV refractory high-entropy alloy spherical powder was prepared by mechanical alloying and radio frequency plasma spheroidization using elemental powder as raw material. Focused on studying the influence of ball milling time and radio frequency plasma spheroidization process on powder phase, morphology, particle size and impurity content, and used X-ray diffractometer, scanning electron microscope, transmission electron microscope, carbon sulfur meter, oxygen nitrogen and hydrogen meter and Laser particle size analyzer, etc. are used to analyze and characterize the powder properties. The results show that as the ball milling time increases, the low melting point elements gradually become solid solution to the high melting point elements. When the ball milling time is 14 h, refractory high-entropy alloy powder with a single BCC phase structure can be formed. The particle size gradually becomes refined with the prolongation of the ball milling time, and the impurity content increases with the prolongation of the ball milling time. Powder milled for 2 h was selected for radio frequency plasma spheroidization. The median particle size of the spheroidized powder was 66.0 μm, the oxygen and carbon contents were 540 ppm and 210 ppm respectively, and the powder flowability was significantly improved to 8.4 s·(50 g)? 1, the tap density reaches 8.80 g·cm?3.