Investigation of mechanical properties and microstructures of GH536 fabricated by laser powder bed fusion additive manufacturing

Laser powder bed fusion additive manufacturing of superalloys has received increasing attention in these years. In this article, the influence of parameters of laser powder bed fusion on mechanical properties and microstructures of nickel-based superalloy GH536 was investigated. Influence of laser power, scanning speed, hatch space and building direction on mechanical properties was discussed, and the optimal parameters were obtained. The relative density of samples fabricated by laser powder bed fusion could be as high as 99.5%. The processing window of laser energy density with 8.56 x 10(4)-1.15 x 10(5)J/cm(3)should be employed to make sure that the relative density is higher than 98%. The ultimate tensile strength and yield stress of GH536 sample made by laser powder bed fusion were 950 and 606 MPa, respectively, which were superior to samples with the tensile strength of 767 MPa and yield strength of 379 MPa prepared by traditional hot forging method. The hardness of the sample could reach 316.8 HV.