Gu Y W, Khor K A, Pan D, Cheang P
School of Mechanical & Production Engineering, Nanyang Technological University, 50, Nanyang Avenue, Singapore 639798, Singapore.
Biomaterials. 2004 Jul;25(16):3177-85. doi: 10.1016/j.biomaterials.2003.09.101.
Hydroxyapatite (HA)/yttria stabilized zirconia/Ti-6Al-4V bio-composite coatings deposited onto Ti-6Al-4V substrate through a plasma spray technique were immersed in simulated body fluid (SBF) to investigate their behavior in vitro. Surface morphologies and structural changes in the coatings were analyzed by scanning electron microscopy, thin-film X-ray diffractometer, and X-ray photoelectron spectroscopy. The tensile bond strength of the coatings after immersion was also conducted through the ASTM C-633 standard for thermal sprayed coatings. Results showed that carbonate-containing hydroxyapatite (CHA) layer formed on the surface of composite coatings after 4 weeks immersion in SBF solution, indicating the composite coating possessed excellent bioactivity. The mechanical properties were found to decrease with immersion duration of maximum 56 days. However, minimal variation in mechanical properties was found subsequent to achieving supersaturation of the calcium ions, which was attained with the precipitation of the calcium phosphate layers. The mechanical properties of the composite coating were found to be significantly higher than those of pure HA coatings even after immersion in the SBF solution, indicating the enhanced mechanical properties of the composite coatings.
通过等离子喷涂技术沉积在Ti-6Al-4V基体上的羟基磷灰石（HA）/氧化钇稳定氧化锆/Ti-6Al-4V生物复合涂层被浸入模拟体液（SBF）中以研究其体外行为。通过扫描电子显微镜、薄膜X射线衍射仪和X射线光电子能谱分析涂层的表面形貌和结构变化。还按照热喷涂涂层的ASTM C-633标准对浸入后的涂层进行拉伸结合强度测试。结果表明，在SBF溶液中浸泡4周后，复合涂层表面形成了含碳酸羟基磷灰石（CHA）层，表明复合涂层具有优异的生物活性。发现机械性能随着浸泡时间的延长而降低，最长浸泡时间为56天。然而，在钙离子达到过饱和（通过磷酸钙层的沉淀实现）之后，发现机械性能的变化极小。即使在浸入SBF溶液后，复合涂层的机械性能也明显高于纯HA涂层，表明复合涂层的机械性能得到了增强。
