High pressure EIGA preparation and 3D printing capability of Ti-6Al-4V powder
(1. School of Material Science and Engineering, Northeastern University, Shenyang 110819, China;
2. Key Laboratory for Laser Application Technology and Equipment of Liaoning Province, Northeastern University, Shenyang 110819, China)
2. Key Laboratory for Laser Application Technology and Equipment of Liaoning Province, Northeastern University, Shenyang 110819, China)
Abstract: Ti-6Al-4V alloy powder was processed by electrode induction melting gas atomization (EIGA) at high gas pressure (5.5-7.0 MPa). The effects of atomizing gas pressure on the powder characteristics and the microstructure, along with the mechanical properties of the as-fabricated block by laser melting deposition (LMD), were investigated. The results indicate that the diameters of powders are distributed in a wide range of sizes from 1 to 400 μm, and the median powder size (d50) decreases with increasing gas pressure. The powders with a size fraction of 100-150 μm obtained at gas pressures of 6.0 and 6.5 MPa have better flowability. The oxygen content is consistent with the change trend of gas pressure within a low range of 0.06%-0.20%. Specimens fabricated by LMD are mainly composed of α+β grains with a fine lamellar Widmanstatten structures and have the ultimate tensile strength (UTS) and yield strength of approximately 1100 and 1000 MPa, respectively. Furthermore, the atomized powders have a favorable 3D printing capability, and the mechanical properties of Ti-6Al-4V alloys manufactured by LMD typically exceed those of their cast or wrought counterparts.
Key words: Ti-6Al-4V powder; high pressure gas atomization; particle size; flowability; 3D printing capability