激光粉末床熔融 (laser powder bed fusion, LPBF) 成形 NiTi 合金由于 Ni 元素的蒸发导致成分偏离粉末设计成分，而 NiTi 合金的形状记忆效应、超弹性等性能受 Ni 含量影响极大。 因此有必要对不同 Ni 含量 NiTi 合金的 LPBF 成形性、显微组织以及力学性能开展研究。 采用真空电极感应熔炼气雾化技术制备了 Ni 50.8 Ti 、 Ni 51.0 Ti 以及 Ni 51.5 Ti( 原子分数，%)3 种预合金粉末，研究其在不同工艺参数下的冶金缺陷、显微组织及力学性能的演化规律。 结果表明，高 Ni 含量 NiTi 合金在 LPBF 成形过程中容易产生垂直于建造方向的裂纹，成形性较低 Ni 含量 NiTi 合金差。 Ni 51.5 Ti 合金室温下的临界应力可达 476 MPa ，但断裂伸长率仅为 2% ； Ni 50.8 Ti 合金临界应力仅为 122 MPa ，断裂伸长率可达 8% 。

Laser powder bed fusion (LPBF) forming of NiTi alloys deviates from the powder design composition due to the evaporation of Ni, and the properties of NiTi alloys such as the shape memory effect and superelasticity are greatly influenced by the Ni content. Therefore, it is necessary to investigate the LPBF formability, microstructure and mechanical properties of NiTi alloys with different Ni contents. In this paper, Ni 50.8 Ti, Ni 51.0 Ti and Ni 51.5 Ti (atomic percent, %) pre-alloy powders were prepared by the electrode induction melting gas atomization technique, and the evolution of metallurgical defects, microstructure and mechanical properties of the three alloys were studied under different process parameters. The results show that the high Ni content NiTi alloy is prone to cracking perpendicular to the building direction during the LPBF forming process, and the formability is worse than that of the low Ni content NiTi alloy. The critical stress of the Ni 51.5 Ti alloy can reach 476 MPa at room temperature, but the fracture elongation is only 2%; the critical stress of the Ni 50.8 Ti alloy is only 122 MPa, and the fracture elongation can reach 8%.