The selected laser melting technology (SLM)was used to prepare GH3536 nickel-based super-alloy,and the changes of the porosity and hardness of the alloy under different process parameters were studied.The best process parameters were selected from the changes of porosity and hardness,and their microstructure was detected and analyzed.The test shows that:when the laser power is 330w and the scanning speed is 950 mm/s,the energy density can be calculated as 128 J/mm3,which a suitable process parameter for SLM forming GH3536 alloy.There are basically no holes on the surface of the alloy,and holes and cracks will appear in different degrees when the energy density is low and high;With the change of laser power and scanning rate,the diffraction peak is shifting,due to the lattice distortion of Ni matrix during SLM forming.As a whole,the hardness of GH3536 alloy increases first and then decreases with the gradual increase of energy density,and the highest Vickers hardness can reach 255.04HV.The microstructure of SLM forming direction is irregular fish-scale molten pool.Molten pool grains are com-posed of equiaxed crystals and columnar crystals.And the columnar crystals grow in the direction of in-verse temperature gradient perpendicular to the molten pool boundary.
关键词
激光选区熔化/GH3536镍基高温合金/能量密度/硬度/显微组织
Key words
laser selective melting/GH3536 nickel base superalloy/energy density/hardness/microstructure
维普
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