Microstructures and wear resistance of laser surface alloyed NiTi with high Mo concentration

K. W. Ng, Hau Chung Man, Tai Man Yue

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

Abstract

Nickel Titanium alloys are a unique class of materials which exhibit shape memory and superelastic properties. The interest in this material for medical applications, such as surgical implants, has been steadily growing in recent years. In the present study, NiTi (55%Ni-45%Ti) SMA were surface alloyed with molybdenum using a continuous wave Nd-YAG laser in Nitrogen shielding gas atmosphere, aiming at improving the surface hardness and in the mean time, enhancing its corrosion resistance. By optimizing the process parameters, an alloyed surface is obtained which has 300Hv increase in hardness as compared with the as received sample. A relatively high Mo content, with average of 30% Mo, in the alloyed zone is achieved for better surface properties. The crosssections of the laser-treated specimens were examined by optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffractometry (XRD). Vickers hardness test recorded a significant improvement in the surface hardness of specimen. Polarization curves consistently showed that the corrosion resistance was enhanced after laser surface alloying with Mo as compared with the untreated NiTi substrate.
Original languageEnglish
Title of host publication26th International Congress on Applications of Lasers and Electro-Optics, ICALEO 2007 - Congress Proceedings
Publication statusPublished - 1 Dec 2007
Event26th International Congress on Applications of Lasers and Electro-Optics, ICALEO 2007 - Orlando, FL, United States
Duration: 29 Oct 20071 Nov 2007

Conference

Conference26th International Congress on Applications of Lasers and Electro-Optics, ICALEO 2007
Country/TerritoryUnited States
CityOrlando, FL
Period29/10/071/11/07

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

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