Effect of laser gas nitriding for biological activities on NiTi alloy

Song Zhang, Chun Hua Zhang, Qiang Wang, Hau Chung Man, Chang Sheng Liu

Research output: Journal article publicationJournal articleAcademic researchpeer-review


NiTi shape memory alloy (NiTi SMA) has been widely used for many medical applications such as dental and orthopaedic implants. Laser gas nitriding is one of the most effective methods to improve the surface performance of NiTi SMA. Laser gas nitrided layer was fabricated on the surface of NiTi SMA after irradiated by a continuous wave Nd:YAG laser in N2environment. With optimum process parameters, a compact laser modified surface metal matrix composite (MMC) coating reinforced with fine TiN was achieved. There was a layer of TiN ceramics on the top of modification layer, with a thickness of 1-2 μm. Then the amount of TiN reinforcement gradually decreases across the coating. Morphology,composition and biological activities were individually investigated by using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and immersion test in simulated body fluid (SBF) at 37°C. The results indicated that there was a good metallurgical bonding between the hard modification layer and the NiTi alloy substrate. Laser gas nitriding can effectively improve the ability of NiTi SMA to induce the formation of bone-like apatite in vitro environment.
Original languageChinese (Simplified)
Pages (from-to)8-11
Number of pages4
JournalZhongguo Jiguang/Chinese Journal of Lasers
Issue numberSUPPL.
Publication statusPublished - 1 Apr 2007


  • Biological activity
  • Biomaterials
  • Laser nitride modification
  • Nickel titanium shape memory alloy
  • Optical design and fabrication

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

Cite this