Linked Life Data

15046891

Source:http://linkedlifedata.com/resource/pubmed/id/15046891

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
2004-3-29
pubmed:abstractText
Plasma sprayed hydroxyapatite (HA) coatings on titanium alloy substrate have been used extensively due to their excellent biocompatibility and osteoconductivity. However, the erratic bond strength between HA and Ti alloy has raised concern over the long-term reliability of the implant. In this paper, HA/yttria stabilized zirconia (YSZ)/Ti-6Al-4V composite coatings that possess superior mechanical properties to conventional plasma sprayed HA coatings were developed. Ti-6Al-4V powders coated with fine YSZ and HA particles were prepared through a unique ceramic slurry mixing method. The so-formed composite powder was employed as feedstock for plasma spraying of the HA/YSZ/Ti-6Al-4V coatings. The influence of net plasma energy, plasma spray standoff distance, and post-spray heat treatment on microstructure, phase composition and mechanical properties were investigated. Results showed that coatings prepared with the optimum plasma sprayed condition showed a well-defined splat structure. HA/YSZ/Ti-6Al-4V solid solution was formed during plasma spraying which was beneficial for the improvement of mechanical properties. There was no evidence of Ti oxidation from the successful processing of YSZ and HA coated Ti-6Al-4V composite powders. Small amount of CaO apart from HA, ZrO(2) and Ti was present in the composite coatings. The microhardness, Young's modulus, fracture toughness, and bond strength increased significantly with the addition of YSZ. Post-spray heat treatment at 600 degrees C and 700 degrees C for up to 12h was found to further improve the mechanical properties of coatings. After the post-spray heat treatment, 17.6% increment in Young's modulus (E) and 16.3% increment in Vicker's hardness were achieved. The strengthening mechanisms of HA/YSZ/Ti-6Al-4V composite coatings were related to the dispersion strengthening by homogeneous distribution of YSZ particles in the matrix, the good mechanical properties of Ti-6Al-4V and the formation of solid solution among HA, Ti alloy and YSZ components.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0142-9612
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4009-17
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Microstructure and mechanical properties of plasma sprayed HA/YSZ/Ti-6Al-4V composite coatings.
pubmed:affiliation
School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Ave, Singapore 639798, Singapore. mkakhor@ntu.edu.sg
pubmed:publicationType
Journal Article, Evaluation Studies