Microstructure and surface properties of laser-remelted titanium nitride coatings on titanium

Abstract Laser remelted tracks were produced on the surface of titanium nitride (TiN) coated titanium. In order to produce different microstructures, seven conditions were tested by varying laser power and speed. The remelted tracks were then evaluated from the surface mechanics point of view through microhardness and sliding friction tests. Samples produced in conditions where laser speed varied from 5 to 100 mm/s presented high TiN surface content and increased hardness. In the velocity range of 20–100 mm/s, the remelted tracks presented high resistance to wear. The dendrites tend to coalescence when the scanning velocity is below 2 mm/s. The low velocity experiments (1 and 2 mm/s) presented eutectoid decomposition of the TiN/Ti phases creating a Ti2N phase at boundaries, which decreased the hardness and the wear resistance at surface. The results indicated that the best condition in terms of surface properties is obtained when the scanning rate is 5 mm/s and the laser power is 500 W.

[1]  J. Chen,et al.  Fabrication of Ti–O/Ti–N duplex coatings on biomedical titanium alloys by metal plasma immersion ion implantation and reactive plasma nitriding/oxidation , 2001 .

[2]  G. Montavon,et al.  Surface preparation and thermal spray in a single step: The PROTAL process—Example of application for an aluminum-base substrate , 1999 .

[3]  Junying Chen,et al.  Properties of titanium oxide biomaterials synthesized by titanium plasma immersion ion implantation and reactive ion oxidation , 2000 .

[4]  B. B. Nayak,et al.  Surface nitriding of titanium in arc plasma , 2003 .

[5]  G. Saindrenan,et al.  Mechanical, structural and tribological properties of titanium nitrided by a pulsed laser , 1998 .

[6]  Stefano Mischler,et al.  The effect of mechanical and electrochemical parameters on the tribocorrosion rate of stainless steel in sulphuric acid , 2003 .

[7]  Isothermal and Cyclic Plasma Nitriding of Titanium Alloys , 1986 .

[8]  V. M. Weerasinghe,et al.  Laser surface nitriding of titanium and a titanium alloy , 1996 .

[9]  Orfeo Sbaizero,et al.  Bioactivity of TiN-coated titanium implants , 2004 .

[10]  S. Gobbi,et al.  Laser welding for lightweight structures , 1997 .

[11]  C. Brebbia,et al.  Computational Methods in Materials Characterisation , 2003 .

[12]  R. Boyer.  An overview on the use of titanium in the aerospace industry , 1996 .

[13]  W. Steen,et al.  Laser Surface Alloying of Titanium Substrates with Carbon and Nitrogen , 1985 .

[14]  S. Deevi,et al.  Single layer and multilayer wear resistant coatings of (Ti,Al)N: a review , 2003 .

[15]  C. Chung,et al.  Room-temperature growth of high-purity titanium nitride by laser ablation of titanium in a nitrogen atmosphere , 1998 .

[16]  D. Landolt,et al.  Tribocorrosion behavior of plasma nitrided Ti–6Al–4V alloy in neutral NaCl solution , 2001 .

[17]  Bekir Sami Yilbas,et al.  Laser treatment and PVD TiN coating of Ti–6Al–4V alloy , 2000 .

[18]  H. Rack,et al.  Titanium alloys in total joint replacement--a materials science perspective. , 1998, Biomaterials.