近球形WMoTaTi难熔高熵合金粉末的制备及性能

Preparation and properties of quasi-spherical WMoTaTi refractory high entropy alloy powders

利用机械合金化结合气固流化技术对WMoTaTi元素混合粉进行预合金化和改性处理,改善粉末形貌、球形率和流动性等特性,使其基本满足3D打印工艺要求。采用X射线衍射仪、扫描电子显微镜、能谱分析仪等实验设备表征粉末表面形貌、粒度分布、流动性、相组成、化学成分等特性。结果表明,经过机械合金化的WMoTaTi元素混合粉末为BCC单相,预合金化效果良好,但预合金粉末球形率仅为26.7%;经流化改性处理后,粉末粒度分布变窄,球形率提高至66.7%,中位径为15.7μm,元素分布均匀,粉末流动性提高至(35.3±0.2)s·(50 g)^(−1),粉末铺展效果良好,可作为3D打印技术的粉末原料。

Mechanical alloying combined with the gas-solid fluidization technology was used to pre-alloy and modify the WMoTaTi elemental mixed powders to improve the powder morphology,sphericity,and flowability,basically meeting the requirements for 3D printing.X-ray diffraction(XRD),scanning electron microscopy(SEM),and energy dispersive spectrometer(EDS)were used to characterize the surface morphology,particle size distribution,flowability,phase constituent,and chemical composition of the powders before and after fluidization.In the results,the mechanically alloyed WMoTaTi powders show the BCC single phase with good pre-alloying effect,but the sphericity of the pre-alloyed powders is only 26.7%.After the fluidization modification,the particle size distribution of the pre-alloyed powders becomes narrower,the sphericity ratio increases to 67.7%,the median diameter of WMoTaTi powders is 15.7μm,the elemental distribution of powders is relatively uniform,the powder flowability increases to(35.3±0.2)s·(50 g)^(−1),and the spreading performance of powders is much better than that before fluidization,which can be used as the raw feedstock for 3D printing.