Preparation of Ti6Al4V powder with high yield of fine particle by crucible-less gas atomization technology

Abstract:

This study aims at producing sphere Ti6Al4V powders with tailed physical characteristics for additive manufacturing application. Ti6Al4V powders were prepared by a novel electrode induction guiding gas atomization (EIGA) equipment designed independently. The yielding rate of fine powders could be improved by reasonably increasing feed rate and atomization gas pressure. Interestingly, the yield (35%) of powder particles below 45μm by EIGA is significantly higher than the yield (~ 10%) by conventional plasma rotating electrode technology. The powder properties and microstructure were characterized by scanning electron microscope (SEM), X ray diffraction (XRD) and optical microscope (OM). The powders exhibited satisfactory flowability and high apparent density for good sphericity and smooth surface. The powders with tailed size ranges could be used for various additive manufacturing methods and injection moulding etc. The β phase of Ti6Al4V translates to needle-like α′ phase during atomization process because of fast cooling rate calculated to be 104-108 K/s.

Key words:Ti6Al4V powders; Gas atomization; Microstructure; Additive manufacturing; Cooling rate