Bio-Ceramic Composite Coatings by Cold Spray Technology

Bioceramics such as hydroxyapatite (HAP) have been conventionally deposited by plasma spray technique. However, due to the inherent high temperature in the plasma, deleterious effects such as evaporation, phase alteration, residual stress, debonding, and gas release etc., commonly occur in these coatings. This paper presents a novel approach to deposit bioceramic coatings at temperatures well below their melting point by cold spray, using composite powders of titanium and HAP. The influence of the process parameters, powder type as well as HAP to titanium ratio has been investigated. It was observed that dense composite coatings, containing up to 30% HAP can be deposited by this technique. Due to widely differing physical characteristics between the powders, as well as the adhesion mechanism, the HAP content in the deposit was a few percent lower than the powder mixture. XRD analysis indicated that the phase composition of the HAP in the deposit was identical to that of the powder. Further, the bond strength of the deposit was comparable/better to that of the plasma sprayed HAP. Coatings deposited using this process hold tremendous potential for improving bone integration of a wide range of dental and orthopedic implants.

[1]  M. Freeman,et al.  The effect of hydroxyapatite coating on ingrowth of bone into cavities in an implant. , 1991, The Journal of arthroplasty.

[2]  Chang-Jiu Li,et al.  Deposition characteristics of titanium coating in cold spraying , 2003 .

[3]  K A Gross,et al.  Material fundamentals and clinical performance of plasma-sprayed hydroxyapatite coatings: a review. , 2001, Journal of biomedical materials research.

[4]  Soo Yong Lee,et al.  Correlation between Al2O3 particles and interface of Al–Al2O3 coatings by cold spray , 2005 .

[5]  Mahnaz Jahedi,et al.  Rare Earth/Metal Composite Formation by Cold Spray , 2008 .

[6]  P. Shipway,et al.  Production of titanium deposits by cold-gas dynamic spray: Numerical modeling and experimental characterization , 2005, Thermal Spray 2005: Proceedings from the International Thermal Spray Conference.

[7]  P. Fox,et al.  Experimental study of titanium/aluminium deposits produced by cold gas dynamic spray , 2006 .

[8]  P. Shipway,et al.  Effect of cold spray deposition of a titanium coating on fatigue behavior of a titanium alloy , 2006 .

[9]  H. Liao,et al.  Effect of heat treatment on microstructure and mechanical properties of cold sprayed Ti coatings with relatively large powder particles , 2009 .

[10]  Tobias Schmidt,et al.  Development of a generalized parameter window for cold spray deposition , 2006 .

[11]  C. Berndt,et al.  Deposition efficiency, mechanical properties and coating roughness in cold-sprayed titanium , 2002 .

[12]  C. Berndt,et al.  Cold spray processing of titanium powder , 2000 .

[13]  T. V. Steenkiste Kinetic sprayed rare earth iron alloy composite coatings , 2006 .

[14]  C. Ding,et al.  Bond strength of plasma-sprayed hydroxyapatite/Ti composite coatings. , 2000, Biomaterials.

[15]  C. Zhang,et al.  Significant influences of metal reactivity and oxide films at particle surfaces on coating microstructure in cold spraying , 2007 .

[16]  C. Doyle,et al.  Plasma sprayed hydroxyapatite coatings on titanium substrates. Part 1: Mechanical properties and residual stress levels. , 1998, Biomaterials.

[17]  C. Zhang,et al.  Ti and Ti‐6Al‐4V Coatings by Cold Spraying and Microstructure Modification by Heat Treatment , 2007 .

[18]  M. Jahedi,et al.  Elimination of porosity in directly fabricated titanium via cold gas dynamic spraying , 2009 .

[19]  A. Kashirin,et al.  Metal particle deposition stimulation by surface abrasive treatment in gas dynamic spraying , 2006 .

[20]  G. G. Stokes "J." , 1890, The New Yale Book of Quotations.

[21]  Hyun-Ki Kang,et al.  Tungsten/copper composite deposits produced by a cold spray , 2003 .