等离子喷涂羟基磷灰石涂层结晶度的分析

采用大气等离子喷涂技术,在Ti6Al4V基体上制备了羟基磷灰石涂层.利用光学显微镜、SEM和XRD分析技术对涂层形貌、相组成和结晶度进行了研究,分析了不同工艺参数对结晶度的影响.结果表明,在喷涂过程中,晶态HA部分发生分解,形成TCP、TTCP、CaO等杂质相,熔化颗粒激冷产生大量非晶;减小喷涂电流,缩短喷涂距离,降低辅助气体流量,均使涂层结晶度增大,杂质相含量降低;1#(结晶度为34.8%)涂层横截面呈典型的层状组织、粉末几乎被完全熔化,2#(结晶度为43.9%)和3#(结晶度为50.6%)涂层的横截面层状组织不明显且含有较多未熔化颗粒.

Crystallinity Analysis of Plasma Sprayed HA Coatings

Hydroxyapatite(HA) coatings on Ti6Al4V substrate were deposited by atmospheric plasma spraying(APS) process.The microstructure of HA coatings was studied by optical and scanning electron microscope(SEM),and X-ray diffractometer(XRD) was applied to investigating the phase composition and crystallinity of the coatings.Relationship of crystallinity and plasma parameters were investigated.Experimental results indicate that HA partially decomposes into impurities such as TCP,TTCP and CaO,et al,and amorphous phase formes because of fast cooling rate of the molten particle.The decrease of current,spraying distance and assistant gas flow could increase the crystallinity with a decrease of the impurities.Cross-sectional morphology of coating 1~#(crystallinity=34.8%)exhibits a typical lamellar structure with seldom unmolten particles while coating 2~#(crystallinity=43.9%)and 3~#(crystallinity=50.6%) are in reverse.