电压对复合氧化法制备含钙磷的多孔氧化钛涂层结构的影响

INFLUENCE OF VOLTAGE ON STRUCTURES OF POROUS TITANIA COATINGS WITH Ca AND P PREPARED BY COMPOUND OXIDATION METHOD

为了分析电压对复合氧化法(即预阳极氧化和微弧氧化复合处理)制备多孔二氧化钛涂层的结构和性能的影响,利用X射线衍射、扫描电镜、显微硬度计、涂层划痕仪等对涂层的结构、形貌、元素组成、硬度及结合强度进行了观察测试。结果表明:电压对多孔二氧化钛涂层的结构和性能有很大影响.电压较低时,涂层由纯锐钛矿型二氧化钛组成;电压较高时,涂层由锐钛矿和金红石混合型二氧化钛组成;随着电压的增加,涂层表面最大微孔孔径增大,凹凸起伏变得明显,显微硬度增加,涂层的钙磷原子比也发生了变化。当电压为250,300,350和400 V时,涂层中的钙磷摩尔比分别为1.27,1.86,1.52和1.82。在300 V电压下可得到结构和性能较为理想多孔二氧化钛梯度涂层。

Influence of the voltage on the structure and properties of porous titania coatings prepared by the compound process (pre-oxidation and micro-arc anodic oxidation) was studied by means of SEM, EDS, X-ray diffraction, micro-hardometer and scratching testing machine. The morphologies, phase structures, element compositions, micro-hardness and bonding strength of the coatings were tested. The results show that there are obvious effects on the structure and properties of titania coatings when the voltage changes. The coatings are composed of the pure anatase when the voltage is kept in a low level (250 V and 300 V), while the coatings are composed of the mixture of rutile and anatase when the voltage is higher (350- 450 V). The pores diameter, surface roughness and hardness of the coatings increase with the increase of voltage, and the molar ratios of Ca/P are changed at the same time. When the voltages are 250, 300, 350 V and 400 V, the molar ratios of Ca/P are 1.27, 1.86, 1.52 and 1.82, respectively. The porous titania coating containing Ca and P with preferable microstructure and property can be prepared when the voltage is at 300 V.