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采用激光立体成形技术制备了Ti-80%Ni(质量分数)合金,研究了工艺参量对显微组织和力学性能的影响.结果表明,激光立体成形Ti-80%Ni合金由η-TiNi_3板条和TiNi(B2)+η共晶构成.随着激光扫描速率的增大,η板条逐渐转变为η板条+(TiNi(B2)+η)共晶,η板条尺寸随着扫描速率的增大而减小;随着激光功率的增大,共晶体积分数逐渐增大,η板条逐渐碎断转变为一定取向的块状组织,功率越大,块状组织越细,形成(TiNi(B2)+η)离异共晶组织+板块间(TiNi(B2)+η)共晶组织.激光扫描速率和激光功率的增大均导致硬脆η板条含量减少,合金的成形性和塑性增加.
Ti-80% Ni (mass fraction) alloy was prepared by laser three-dimensional forming technique and the effects of technological parameters on the microstructure and mechanical properties were studied. The results show that Ti-80% And TiNi (B2) + η eutectic.With the increase of the laser scanning rate, the η lamellae gradually transformed into η lamellae + (TiNi (B2) + η) eutectic, and the size of η lamellae with the scanning rate The volume fraction of eutectic gradually increases, and the η plate gradually breaks up into a block-like structure with a certain orientation. The larger the power is, the thinner the block structure is and the formation of (TiNi (B2) + η) dissociation eutectic microstructure + intergranular (TiNi (B2) + η) eutectic structure.The increase of laser scanning rate and laser power all lead to the decrease of the content of hard and brittle η lamella, the formability and plasticity increase.