Formation of TiN Grid on NiTi by Laser Gas Nitriding for Improving Wear Resistance in Hanks' Solution

C. H. Ng, O. K. Chan, Hau Chung Man

Research output: Journal article publicationJournal articleAcademic researchpeer-review

21 Citations (Scopus)

Abstract

Laser gas nitriding (LGN) is a common surface modification method to enhance the wear resistance of titanium (Ti) alloys, which are known to have poor tribological properties. In the present study, a titanium nitride (TiN) grid network was fabricated on the surface of nickel titanium (NiTi) by LGN. The laser processing parameters were selected to achieve nitriding without surface melting and hence to maintain a smooth surface finish. The characteristics of the grid-nitrided samples were investigated by scanning-electron microscopy, X-ray diffractometry, optical microscopy, 2-D profilometry, contact angle measurements and nanoindentation. The wear resistance of the nitrided samples was evaluated using reciprocating wear test against ultra-high-molecular-weight polyethylene (UHMWPE) in Hanks' solution. The results indicate that the wear rates of the grid-nitrided samples and the UHMWPE counter-body in the wear pair are both significantly reduced. The decrease in wear rates can be attributed to the combination of a hard TiN grid and a soft NiTi substrate. In Hanks' solution, the higher hydrophilicity of the nitrided samples also contributes to the better performance in wear test against hydrophobic UHMWPE.
Original languageEnglish
Pages (from-to)459-464
Number of pages6
JournalJournal of Materials Science and Technology
Volume32
Issue number5
DOIs
Publication statusPublished - 1 May 2016

Keywords

  • Laser
  • Nitriding
  • Surface patterning
  • Titanium alloys
  • Wear

ASJC Scopus subject areas

  • Ceramics and Composites
  • Mechanics of Materials
  • Mechanical Engineering
  • Polymers and Plastics
  • Metals and Alloys
  • Materials Chemistry

Cite this