Effect of laser beam energy density distribution on the main properties of laser additive forming of metal parts

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Compared to traditional processing techniques, laser additive manufacturing technology has advantages such as short processing cycles, no molds, and is not limited by complex structures. However, the forming quality of GH3625 nickel-base alloy metal parts is affected by various process parameters, in which the distribution characteristics of laser beam energy density, microstructure and mechanical properties play a key role. In order to investigate the influence of beam energy density distribution on the main properties of GH3625 nickel-based alloy metal parts, the beam energy density distribution was changed by controlling the defocusing amount. Then it sets 5 different defocusing parameters to obtain the corresponding energy density distribution characteristics. Observing and analyzing the various properties of alloy powder from the perspectives of different scanning speeds, laser power, and energy density distribution characteristics. The results show that when the laser power is 600 W, the scanning speed is 700 mm/min, and the energy density distribution is characteristic 4, the metal parts have the best performance. Its density is 99.90%, microhardness is 350.44 HV, tensile strength is 1328 Mpa, friction coefficient is about 0.51, and wear rate is 0.55%. This indicates that the laser additive forming method proposed in this study can effectively improve the hardness, density and other properties of GH3625 nickel-based alloy metal parts to achieve the best state, which provides an important reference for the further optimization of the material preparation process.