等离子喷涂羟基磷灰石/氧化锆复合涂层力学性能分析

Mechanical Properties of Plasma Sprayed Hydroxyapatite/ZrO_2 Composite Coatings

基体Ti-6Al-4V合金表面为羟基磷灰石（HA）涂层的植入体，已经广泛应用于外科整形临床手术中。为了提高涂层和基体的结合强度，本试验分别制备了90HA-10ZrO2和70HA-30ZrO2（按质量分数计）2种成分的复合涂层和纯HA涂层。复合粉末采用机械搅拌法制备粒径约为75～106μm，采用装备有NX100型Aotoman机械手的Metco 9M喷涂设备制备涂层。测量了涂层的结合强度（ISO13779—4：2002），采用SEM对涂层表面形貌和涂层微结构进行了分析，XRD分析了涂层相组成和结晶度。结果表明采用等离子喷涂（APS）制备的HA涂层熔化效果很好，但涂层中有未熔化的ZrO2颗粒，而且30％ZrO2的未熔颗粒明显多于前者。2种复合涂层的结合强度都要高于纯HA涂层。

Hydroxyapatite (HA) coating on Ti-6Al-4V alloy is a common implant used in orthopedics applications. To bridge the gap in plasma sprayed HA coatings having low bond strength, HA/ZrO2 composite coatings were developed in this study. A comparison is made between two different kinds of composite feedstock, namely HA and ZrO2 in the ratio of 90:10 wt% and 70:30 wt%, respectively. Composite powders in the size range of 75～106 um were prepared by the mixing method. The powder was deposited onto Ti-6Al-4V substrate by means of Metco 9M plasma spray systems equipped with Motoman NX100 robot. The mechanical properties of the individual layers were tested using the tensile adhesion test (ISO 13779-4:2002). The surface morphology and microstructure of the composite layers were examined by a back-scattered scanning electron microscope. The phase composition and crystallinity were determined by an X-ray diffractometer. The investigation shows that the as-sprayed coating of the individual layers possesses unmelted particles. In other words, the more unmelted particles coating is in the ratio of 70:30 wt%. The tensile adhesion test revealed a more higher bond strength for the composite coatings compared to that for pure HA coatings.