Abstract: TC4 alloy powders for laser 3D printing were prepared by electrode induction melting gas atomization (EIGA). The effects of different pressures on printable powder production rate， particle size， powder morphology， apparent density， flow ability and hollow powder rate were studied. The results showed that by increasing gas pressure， the printable powder production rate and powder sphericity increase， while the particle size decreases. When the gas pressure is 6.0MPa， the powder production rate is over 50%， the average particle size is below 100μm， the apparent density is 2.950g/cm³， the flow ability is 2.242g/s and the hollow powder rate is below 3%. When the gas pressure is 7.0MPa， the broken powder and hollow powder rate increase dramatically. By comparing the tensile stress-strain curve and fractograph of the samples made by the powders with different particle size under 6.0MPa， it is found that the laser 3D printing sample using TC4 alloy powders ranging from 50 to 100μm has better strength and toughness， corresponding to the tensile strength of 907.7MPa and the ductility of 15.3%.

Key words: gas atomization, laser 3D printing, TC4 alloy powder, powder morphology, apparent density, hollow powder rate