钛基Ca-P涂层相组成的定量分析及降解性能研究

Characteristics of Crystal Structure and Biodegradablity of Titanium-Based Ca-P Coatings

采用大气等离子喷涂技术,在纯钛表面喷涂制备钙磷(Ca-P)涂层,分析两种喷涂工艺下形成的两种特殊形貌晶体的显微结构和元素组成,利用XRD定量分析涂层的相组成及结晶度,并在人体模拟液(SBF)中对涂层的降解性能进行研究。结果表明:在喷涂功率为22kW、喷枪移动速率为400mm/s时涂层表面形成大量方棱状的焦磷酸钙(Ca2P2O7)晶体,结晶度为4.61%,而在喷涂功率为26kW、喷涂距离为300mm/s时则形成大量花瓣状的磷酸四钙(Ca4P2O9)晶体,结晶度为6.02%,喷涂粉体粒度较小使得两种涂层中HA结晶度都较小;生物降解性能研究显示,两涂层降解反应都是由剧烈到平缓的过程,但含Ca2P2O7晶体涂层的降解速率小于含Ca4P2O9晶体的涂层。

Two calcium and phosphate（Ca-P） coatings with special topographies were prepared on the pure titanium substrates by air plasma spraying.The microstructures and composition of the two special crystals were analyzed by SEM and EPMA.The phase compositions and crystallinty of coatings were quantitatively investigated by XRD.The results show that a lot of square prismatic-like dicalcium phosphates（Ca2P2O7） crystals with 4.61% crystallinity were formed under 22 kW spraying power and 400 mm/s rate of gun movement;and a large number of petal-like tetracalcium phosphate（Ca4P2O9） crystals with 6.02% crystallinity were formed under 26 kW spraying power and 300 mm/s rate of gun movement.As a result of the small particle size of the spaying powder,the HA has a low degree of crystallinity in both two coatings.In addition,the study of biodegradation shows that the processes of degradation of the two coatings proceed from fiercely to gently,but the degradation rate of the former is lower than that of the latter.