抄録
The bending strength of thermal spray coatings was investigated using acoustic emission (AE) method and in-situ observation. An atmospheric plasma spray method was used to form the thermal spray coating on steel substrates. Cumulative AE event was rapidly increased at a certain applied bending strain. Macro-cracks were formed in the coating at the AE rapidly increasing point. The macroscopic crack formation is precursory phenomenon of the coating peeling. Therefore, the bending strength of the thermal spray coating can be evaluated by the AE rapidly increasing point. The effects of the residual stress in the coating on the bending strength were investigated. The AE rapidly increasing point was increased with increasing the tensile residual stress.
