Surface chemical and nanomechanical aspects of air PIII-treated Ti and Ti-alloy

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Plasma immersion ion implantation (PIII) of Ti and Ti6Al4V alloy in dry air plasma has been performed with 25 kV negative pulses up to 1.9×10 18 cm -2 doses. For comparison, prolonged (50-100 h), high-temperature (600-650 °C) heat treatment of a similar Ti-alloy in air (TO treatment) was also performed. The changes in chemical composition, structure and hardness of the modified surfaces were studied by XPS, X-ray diffraction (XRD) analysis and nanoindentation measurements. According to XPS, surface oxidation and strong surface enrichment of Al occurred on the Ti-alloys after both the "non-equilibrium" PIII treatment and the "equilibrium" TO treatment. After the air PIII treatment Ti and Al were present in fully oxidized (TiO 2 and Al 2 O 3 ) states, and neither nitrogen nor vanadium could be detected in the topmost layer. XRD showed the formation of rutile and substoichiometric TiO 2-x phases on the PIII-treated Ti and TO-treated Ti-alloy, but no crystalline oxide phase was found on the PIII-treated Ti-alloy. The surface hardness and the scratch resistance of the samples increased significantly after PIII treatment. The surface hardening and the improved scratch resistance of the oxidized Ti-alloy samples can be explained mainly by the surface segregation of Al and the formation of a layer containing oxidized Ti and Al.

Original languageEnglish
Pages (from-to)248-254
Number of pages7
JournalSurface and Coatings Technology
Volume186
Issue number1-2 SPEC. ISS.
DOIs
Publication statusPublished - Aug 2 2004

    Fingerprint

Keywords

  • Nanomechanical properties
  • Ti
  • Ti6Al4V
  • XPS
  • XRD

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

Cite this