等离子喷涂HA/TiO2复合涂层

采用大气等离子喷涂方法，成功地制备了HA／TiO₂复合涂层，对复合涂层的结合强度、微观结构、水浸渍下的表面形貌进行了较为深入的研究．结果表明，由于TiO₂的加入，HA／TiO₂涂层的结合强度明显高于纯HA徐层，而且导致涂层破坏机理由粘合破坏向内聚破坏转化．这是由于HA／TiO₂的复合缓和了涂层与基体间的膨胀系数失配现象，改善了涂层与基体之间的结合．SEM观察显示，HA／TiO₂涂层表面有一些细小的裂纹，但在去离子水中浸泡后就会消失，而且不容易产生新的裂纹，这说明TiO₂的加入不但改善了涂层与基体之间的结合，同时增强了涂层内部颗粒的结合．

Plasma Sprayed HA/TiO2 Composite Coatings

HA/TiO₂ composite coatings were fabricated successfully via atmospheric plasma spraying, whose bonding strength, microstructure and surface mophology after immersion in deionized water were investigated. The obtained results reveal that the bonding strengthes of HA/TiO₂ composite coatings are much higher than that of HA coating and the fracture mechanism of the coating changes from adhesive failure to cohesive failure owing to the addition of TiO₂ in the coating. The reason for this is the addition of TiO₂ in the coating reduces the mismatch of thermal expansion coefficient between the coating and the substrate. SEM obeservation shows that there are some micro cracks in the composite coatings which disappear after immersion in deionized water for a day, and almost no new cracks generate again. This means that both the adhesive strength and the cohesive strength are improved by the addition of TiO₂ in the coating.