Microstructure and Properties of CuCrZr Fabricated by Laser Powder Bed Fusion
DONG Peng1, WANG Yang1, ZHANG Lizheng2, 3, LIU Han1, ZHANG Zijia1, ZHANG Jingjing1, WANG Runze1
1. Capital Aerospace Machinery Co., Ltd., Beijing 100076, China;
2. Beijing University of Technology, Beijing 100124, China;
3. Beijing Engineering Research Center of 3D Printing for Digital Medical Health, Beijing 100124, China
CuCrZr alloy complex structural parts were prepared by laser powder bed fusion (L-PBF). Under the optimum forming process parameters, the alloy samples with relative density of 99.65% were prepared, and the microstructure and properties of L-PBF forming samples in different directions were studied. The results show that the microstructure of XOY plane is equiaxed grains with different grain sizes. The microstructure morphology of the XOZ plane shows that the columnar crystal grows through the forming layer along the forming direction, the grain size is large, and there are semi-circular molten pools. The microhardness of XOY plane of CuCrZr alloy is higher than that of XOZ plane, and the tensile property of tensile samples at XOY plane and XOZ plane is slightly different. There are a large number of dimples in the tensile fracture morphology, which is a ductile fracture dominated by plastic deformation. The free electrons in the XOY plane are transmitted through the coarser columnar crystals, and the grain boundaries produce less scattering. The free electrons in the XOZ plane are transmitted through the equiaxed grains perpendicular to the forming direction, and the scattering effect generated by the grain boundary is large, so the electrical conductivity and thermal conductivity of the XOZ plane are lower than those of the XOY plane.