Thermal Sprayed Ceramic Coating with Self-Healing-Up Effect

结果表明，喷涂氧化铝涂层在空气中加热时，基体原子向涂层中扩散，形成脉状氧化物，并通过脉状氧化物的形成来修复涂层中的孔洞或裂纹。脉状氧化物由双重结构组成，其中在空隙或裂纹的自由表面处形成含有氧、铝和金属基底原子的尖晶石层，并且不含铝的金属氧化物位于脉状氧化物的核心处。据认为，脉状氧化物的执行作为在自由表面的尖晶石层的优先形成和随后的金属氧化物在芯部的生长的结果。此外，Ni、Co和Ti的基材可用于获得尖晶石相，因此可用于愈合涂层中的空隙或裂纹。从这一点来看，只有当选择基质以形成尖晶石相时，才能显示愈合效果。结果表明，尖晶石相的形成对愈合效果起着重要作用。

It has been confirmed that atoms of substartes diffuse into the sprayed alumina coating to form veined oxides on heating in air and the voids or cracks are healed up by the veined oxide formation. The veined oxides compose of a duplicated structure where a spinel layer containing oxygen, aluminum and atoms of the metallic substrate forms at the free surface of the voids or cracks and a metallic oxide free from aluminum is located at the core of the veined oxides. It is considered that the veined oxides are performed as a results of the preferential formation of the spinel layer at the free surface and subsequent growth of the metallic oxides at the core. Furthermore, substrates of Ni, Co, and Ti are useful in obtaining the spinel phase and therefore in healing up the voids or cracks in the coating. From this point of view, the healing-up effect can reveal only when a substrate is selected so as to form the spinel phase. It is concluded that the formation of the spinel phase plays an important role in the healing-up effect.