Adhesion study of pulsed laser deposited hydroxyapatite coating on laser surface nitrided titanium

Hau Chung Man, K. Y. Chiu, F. T. Cheng, K. H. Wong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

48 Citations (Scopus)

Abstract

Hydroxyapatite (HA) coatings were fabricated by pulsed laser deposition (PLD) on commercially pure titanium which had been subjected to different types of pre-treatment. These include: (i) 60-grit SiC grinding, (ii) 320-grit SiC grinding, (iii) 1-μm diamond paste mirror-finishing, (iv) etching with Knoll solution, and (v) laser surface nitriding followed by selective etching. The HA coatings were pulsed laser deposited at different water-vapor pressures to determine the optimal processing conditions. The nitrided-etched specimen exhibits a three dimensional TiN dendritic network which promotes the adhesion between HA coating and titanium substrate. Among the specimens with different pre-treatments, the adhesion strength of HA is the highest for the nitrided-etched specimen, reaching about twice that for the mirror-finished specimen. Thin-film X-ray diffraction shows a high degree of crystallinity for the PLD deposited HA. According to energy-dispersive X-ray analysis, the Ca/P ratio of the deposited HA reaches an approximate value of 1.7, similar to that of the HA target. Scanning-electron microscopy reveals that the deposited HA is about 4 μm in thickness. Growth of apatite was rapidly induced on the HA coated specimens when immersed in Hanks' solution for 4 days, indicating that the PLD HA coating is highly bone bioactive. This could be partly due to the high wettability of the PLD HA surface.
Original languageEnglish
Pages (from-to)5496-5501
Number of pages6
JournalThin Solid Films
Volume517
Issue number18
DOIs
Publication statusPublished - 31 Jul 2009

Keywords

  • Adhesion
  • Hydroxyapatite
  • Nitriding
  • Pulsed laser deposition
  • Titanium

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

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