Effects of Milling and Heat Treatment on the Synthesis of NiTi Powders

• Published in: Journal of Wuhan University of Technology. Materials science edition 2017-10, Vol.32 (5), p.1156-1162
• Main Authors: Sadeghi, A. R., Mostajabodaveh, H., Babakhani, A., Abravi, M. S., Salehi, A.
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Heat treating; Heat treatment; Homogeneous structure; Intermetallic compounds; Materials Science; Metallic Materials; Nickel base alloys; Nickel compounds; Nickel titanides; NiTi; Particle physics; Scanning electron microscopy; Titanium compounds; Titanium oxides; X射线衍射仪; 层状结构; 扫描电子显微镜; 热处理; 粉末合成; 行星球磨机; 镍钛
• ISSN: 1000-2413; 1993-0437
• DOI: 10.1007/s11595-017-1725-4

This work reports on the production of Ni-50 at% Ti powders by a planetary ball mill in various times（0.5, 1, 2, 6, 20, 36, 54 and 120 h） and subsequent heat treatment in Ar atmosphere at 820 °C. Study of powders structure after milling and heat treatment was carried out by scanning electron microscopy and X-ray diffractometry. According to the results, after milling for 6 hours NiTi phase formed, and by the milling evolution up to 54 h, it became the dominant phase. It was found that by the milling development, a layer structure in powder particles was formed, also by increasing the milling time a more homogeneous structure was obtained. Amorphous Ni Ti transformed into ordered Ni Ti, Ni_3Ti, NiTi_2 and minor TiO_2 and TiO after heat treatment at 820 °C for 1 h.