CO2 laser gas assisted nitriding of Ti-6Al-4V alloy


Yibas B. S. , Karatas C., Uslan U. , KELEŞ Ö. , Usta I. Y. , Ahsan M.

APPLIED SURFACE SCIENCE, vol.252, no.24, pp.8557-8564, 2006 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 252 Issue: 24
  • Publication Date: 2006
  • Doi Number: 10.1016/j.apsusc.2005.11.076
  • Title of Journal : APPLIED SURFACE SCIENCE
  • Page Numbers: pp.8557-8564
  • Keywords: laser, nitriding, Ti-6Al-4V, microstructure, phases, INCLUDING EVAPORATION PROCESS, LASER, TITANIUM, PLASMA

Abstract

Laser gas assisted nitriding of Ti-6Al-4V alloy is carried out and nitride compounds formed and their concentration in the surface vicinity are examined. SEM, XRD and XPS are accommodated to examine the nitride layer characteristics. Microhardness across the nitride layer is measured. Temperature field and nitrogen distribution due to laser irradiation pulse is predicted. It is found that the nitride layer appears like golden color; however, it becomes dark gold color once the laser power irradiation is increased. The delta-TiN and epsilon-TiN are dominant phases in the surface vicinity. The needle like dendrite structure replace with the feathery like structure in the surface region due to high nitrogen concentration. No porous or microcracks are observed in the nitrided layer, except at high power irradiation, in this case, elongated cracks are observed in the surface region where the nitrogen concentration is considerably high. (c) 2005 Elsevier B.V. All rights reserved.