电流密度对复合氧化法制备涂层结构的影响

对TiO2薄膜涂层的结构、形貌、元素组成、硬度进行了观察和测量,研究了电流密度对复合氧化法(即预氧化和微弧氧化复合处理)制备多孔TiO2涂层的结构和性能的影响.结果表明:电流密度对多孔TiO2涂层的结构和性能有很大影响.随着电流密度的增加,涂层的锐钛矿型TiO2含量减少,金红石型TiO2含量增加,涂层表面微孔孔径增加,凹凸起伏变得明显,显微硬度增加,钙磷原子比也发生了变化.当电流密度为20,40,60,80和100 mA/cm2时,涂层的钙磷摩尔比为1.22,1.60,1.89,2.01,2.12.在40 mA/cm2电流密度下可得到结构和性能较理想的多孔TiO2梯度涂层.

Effect of micro--arc oxidation current density on the structure of the coatings by a compound oxidation preparation

Influence of the current density 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 and micro-hard meter. The morphologies, phase structures, element compositions and micro-hardness were tested. The results show that there are obvious effects of the current density on the structure and properties of titania coatings. The coatings are mainly composed of anatase when the current density is kept in a low level (20 mA/cm2). When the current density increases, anatase decreases and rutile increases. The pores diameter, surface roughness and hardness of the coatings increase, and the molar ratios of Ca/P are changed at the same time. When the current density are 20, 40, 60, 80 and 100 mA/cm2, the molar ratios of Ca/P are 1.22, 1.60, 1.89, 2.01, 2.12, respectively. The porous titania coating containing Ca and P with preferable microstructure and property can be prepared when the current density is at 40 mA/cm2.