两种3D打印用雾化Ti-6Al-4V粉末的对比研究

本研究分别利用水冷铜坩埚真空感应熔炼气雾化(VIGA-CC)和等离子旋转电极(PREP)两种技术制备出球形Ti-6Al-4V合金粉末,作者利用SEM、同步辐射CT扫描-三维重建和氩气含量测试等分析手段对不同粒径的Ti-6Al-4V合金粉末的孔洞缺陷和氩气含量、硬度值进行了表征。实验结果表明, VIGA-CC粉末粒度分布宽,细粉收得率较多,粉末粒度分布在40~180 μm之间, PREP粉末的粒度分布较窄,主要集中在110~180 μm之间；金属粉末内部的孔隙率、气体含量和孔尺寸随着粉末粒度的增大而增大,且同一粒径范围内VIGA-CC粉末的气孔概率多于PREP粉末；随着粉末粒径减小,粉末截面组织逐渐细化,其硬度值逐渐升高,整体上VIGA-CC粉末硬度值高于PREP粉末。

Comparative Study of Two Kinds of Atomized Ti-6Al-4V Powders for 3D Printing

In this study, spherical Ti-6Al-4V alloy powders were prepared by vacuum induction melting (VIGA-CC) in a water-cooled copper crucible and plasma rotating electrode (PREP). The void defects, argon content and hardness of Ti-6Al-4V alloy powders with different particle sizes were analyzed by means of SEM, synchrotron radiation CT scanning-three-dimensional reconstruction and argon content measurement. The experimental results show that the particle size distribution of VIGA-CC powder is between 40 and 180 microns. The particle size distribution of PREP powder is narrow, mainly between 110 and 180 microns. The VIGA-CC powders exhibited higher fraction of fine powders compared with PREP powders. The porosity, Ar content and pore size of metal powder increase with the increase of particle size, and the pore size of VIGA-CC powder is larger than PREP powders within the same particle size range. With decreasing the particle size, the cross-section structure of the powder becomes finer, and resulting in the increase of the hardness value. Overall hardness value of VIGA-CC powder is higher than that of PREP powder.