Abstract：NiCrFeAl alloy was prepared by selective laser melting (SLM) using NiCrFeAl prealloy powders as raw material. The optimizing of SLM processing parameters was carried out through optical analyzing on pores. Scanning electron microscope was ultilized for microstructure characterization of the alloy, and defects were analyzed by EBSD. The mechanical properties tests were carried out on UTM 5105 electronic universal testing machine. Results show that the optimal processing parameters of NiCrFeAl alloy fabrication are as follows: laser power of 240 W, scanning speed of 1 000 mm/s, hatching spacing of 0.12 mm and layer thickness of 0.03 mm. The corresponding tensile strength and elongation are 535 MPa and 5.8% respectively. There are solid cracks distributed between adjacent grains with large misorientation, showed intergranular fracture on horizontal and vertical cross sections. The average grain size on the horizontal cross section of the alloy is 35 μm, and the low angle grain boundaries accounts for 37.0%. The average grain size on the vertical section is 56 μm, and the low angle grain boundaries accounts for 41.0%.
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