Forming parameter optimization and electrolytic polishing of lattice structures in laser powder bed fusion NiTi alloy
ZHAO Junzhe1, YANG Rui1, WANG Minbo1,2,3, CHAI Yuqing1, PENG Yue1, ZHENG Dan2
1. School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan 411201, China; 2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China; 3. CNNC Jianzhong Nuclear Fuel Co., Ltd, Yibin 644000, China
Abstract：NiTi alloys, known for their shape memory effect, superelasticity, and excellent biocompatibility, are widely used in aerospace and biomedical fields. In this study, Ni50.95Ti alloys were fabricated via laser powder bed fusion to systematically investigate the effects of laser power and scanning speed on metallurgical defects and microhardness. The microstructural features of the scan and build surfaces under optimal processing conditions were characterized, and the regulation effect of electrolytic polishing on the surface morphology of lattice nodes was evaluated. Results show that low scanning speeds (450, 550 mm/s) tend to induce cracks, while higher scanning speeds (650~850 mm/s) significantly improve densification, however, energy densities above 110 J/mm3 promote pore formation. Under optimal parameters (135 W, 650 mm/s), the alloys consisted of B2 austenite and B19′ martensite exhibit〈100〉//BD and〈110〉//BD textures, and are crack-free. Electrolytic polishing for 3 min effectively remove unmelted powders, produce a smooth and pit-free surface, providing process support for the application of lattice-structured NiTi alloys in biomedical field.
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2026, Vol. 31 
