Tags

Type your tag names separated by a space and hit enter

Microstructure and mechanical properties of plasma sprayed HA/YSZ/Ti-6Al-4V composite coatings.
Biomaterials. 2004 Aug; 25(18):4009-17.B

Abstract

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.

Authors+Show Affiliations

School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Ave, Singapore 639798, Singapore. mkakhor@ntu.edu.sgNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Evaluation Study
Journal Article

Language

eng

PubMed ID

15046891

Citation

Khor, K A., et al. "Microstructure and Mechanical Properties of Plasma Sprayed HA/YSZ/Ti-6Al-4V Composite Coatings." Biomaterials, vol. 25, no. 18, 2004, pp. 4009-17.
Khor KA, Gu YW, Pan D, et al. Microstructure and mechanical properties of plasma sprayed HA/YSZ/Ti-6Al-4V composite coatings. Biomaterials. 2004;25(18):4009-17.
Khor, K. A., Gu, Y. W., Pan, D., & Cheang, P. (2004). Microstructure and mechanical properties of plasma sprayed HA/YSZ/Ti-6Al-4V composite coatings. Biomaterials, 25(18), 4009-17.
Khor KA, et al. Microstructure and Mechanical Properties of Plasma Sprayed HA/YSZ/Ti-6Al-4V Composite Coatings. Biomaterials. 2004;25(18):4009-17. PubMed PMID: 15046891.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Microstructure and mechanical properties of plasma sprayed HA/YSZ/Ti-6Al-4V composite coatings. AU - Khor,K A, AU - Gu,Y W, AU - Pan,D, AU - Cheang,P, PY - 2003/01/29/received PY - 2003/10/10/accepted PY - 2004/3/30/pubmed PY - 2004/12/16/medline PY - 2004/3/30/entrez SP - 4009 EP - 17 JF - Biomaterials JO - Biomaterials VL - 25 IS - 18 N2 - 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. SN - 0142-9612 UR - https://www.unboundmedicine.com/medline/citation/15046891/Microstructure_and_mechanical_properties_of_plasma_sprayed_HA/YSZ/Ti_6Al_4V_composite_coatings_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0142961203010445 DB - PRIME DP - Unbound Medicine ER -