The preparation of yttrium-stabilized zirconia (YSZ) thermal barrier coatings (TBCs) using atmospheric plasma spraying (APS) has been extensively investigated. Internal stress is a major factor affecting the performance and service life of TBCs systems. Excessive internal stresses can cause the development and expansion of microcracks and lead to premature failure of YSZ TBCs. Early internal stresses are mainly caused by poor selection of the coating process

substrate and powder conditions

and cause early crack initiation and extension. High temperature phase changes in ZrO

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thermal growth oxide (TGO) growth and coefficient of thermal expansion (CTE) mismatch between ceramic and metallic materials are the ma

in sources of internal stresses in TBCs in thermal service. Under internal stress

cracks sprout at the surface ceramic working layer (TC)/TGO or bonding layer (BC)/TGO interface

expand and lead to coating peeling failure. The main ideas to reduce the internal stresses in the system in order to extend the thermal service life of TBCs are to interfere with spinel TGO generation

to prepare composite coatings or to stabilise the ZrO

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phase structure with rare earth particles.