Abstract：In order to develop low-cost and high-performance special die steel metal of selective laser melting, the 718HH plastic mould steel powder for selective laser melting was prepared by vacuum-air atomization technology. The particle size morphology and fluidity of the powder were detected by laser particle size analyzer, scanning electron microscope, Hall flowmeter and intelligent powder performance tester. Selective Laser Melting (SLM) forming properties of the powders and properties of the formed parts were studied. Tensile tests were conducted to study the mechanical properties of the SLM molded parts of the die steel powder. The results indicate that the particle sizes of D10, D50 and D90 of the test powders are 27.83 μm, 43. 52 μm and 69.09 μm, respectively, and most of the powders are spherical or nearly spherical, with a fluidity of 18.44 s/50g, an apparent den‐ sity of 4. 16 g/cm3， a tap density of 4. 75 g/cm3， and a compressibility of 12. 4%. The 718HH plastic mould steel powder is suitable for melting and forming laser selections. The tensile strength of the formed parts is 1 392 MPa, the yield strength is 1 257 MPa, and the impact toughness is 15. 3 J, and the strength and the toughness are higher than those of domestic 718HH plastic mould steel samples.
2023, Vol. 33 
