| Abstract [eng] |
Ceramic coatings are widely used in modern technology in all kind of fields, from aerospace to automotive industry to protect certain parts or elements from heat. These types of coatings are also known as thermal barrier coatings. Nowadays there is a huge variety of materials and techniques to form ceramic coatings that exhibit various properties. Depending on the application of the coating these qualities can be altered by using different materials, fabrication parameters, or even post-forming processes. This work was focused on determining the influence of heat treatment on the structure, phase, elemental composition and surface roughness of alumina and zirconia coatings formed using plasma spraying. The results showed that using 20 heat cycles on alumina coatings can reduce the surface roughness 1.3 times. Elemental analysis revealed that heat treatment has slight effect on elemental structure of thermal barrier coatings. X-ray diffraction analysis showed that number of heat cycles, slightly affected on phase composition of the coatings. It has been noticed that alumina coatings formed from 98.5 % purity powders exhibited the best adhesion. Even though the alumina coating formed from 99.5 % purity powders needed a nickel underlayer, it also stayed intact after 20 heat treatment cycles. Zirconia coating exhibited the worst adhesion and started to break just after one heat treatment cycle. |
