Novel Method for Hydroxyapatite Coating by Hydrothermal Hot-Pressing via Double Layered Capsule

Abstract:

A new hydrothermal method is proposed which enables us to prepare thin hydroxyapatite (HA) ceramic coatings on Ti substrates with a curved surface at low temperatures. The method uses double layered capsules in order to produce a suitable hydrothermal condition; the inner capsule encapsulates the coating materials and a Ti substrate, and the outer capsule is subjected to isostatic pressing under the hydrothermal condition. In this study, it is demonstrated that a pure HA ceramic layer with the thickness of 50 µm could be coated to a Ti cylindrical rod at the low temperature as low as 135°C under the confining pressure of 40 MPa. Pull-out tests were conducted to obtain an estimate for the adhesion properties of the HA coating prepared by the double layered capsule method. The shear strength obtained from the pull-out tests was in the range of 4.0-5.5 MPa. It was also shown that the crack propagation occurred within the HA coating layer, not along the HA/Ti interface in the pull-out tests.

• Periodical: Key Engineering Materials (Volumes 309-311)
• Pages: 647-650
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.309-311.647
• Online since: May 2006
• Authors: Takamasa Onoki, Toshiyuki Hashida
• Keywords: Coating, Double Layered Capsule, Hydrothermal, Hydroxyapatite (HAP), Pull-Out Testing, Titanium (Ti)

References

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