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