Thermal Sprayed Ceramic Coating with Self-Healing-Up Effect

证实基体原子在空气中加热时扩散到喷涂的氧化铝涂层中形成脉状氧化物，并通过形成脉状氧化物来愈合空洞或裂纹。脉状氧化物由重复结构组成，其中在空洞或裂纹的自由表面形成含有氧、铝和金属基体原子的尖晶石层，并且不含铝的金属氧化物位于脉状氧化物的核心。认为脉状氧化物是自由表面尖晶石层优先形成和芯部金属氧化物随后生长的结果。此外，Ni、Co和Ti的衬底有助于获得尖晶石相，从而愈合涂层中的空洞或裂纹。从这个角度来看，修复效应只有在选择衬底形成尖晶石相时才能显现出来。综上所述，尖晶石相的形成对修复效果起着重要作用。

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.