Abstract
Lateral compression tests for plasma-sprayed CoNiCrAlY coatings were carried out. In considering the deformation of tubes, the elastic contact with a flat plate and a tube surface was taken into account as well as the bending of the curved beam of the tube. Young's modulus of mild steel tubes obtained from the lateral compression tests agreed well with the true value. In order to examine the effects of spraying processes on mechanical properties of sprayed coatings, coatings were sprayed by both Atmospheric Plasma Spray(APS) and Low Pressure Plasma Spray(LPPS) and three types of spraying powder size were selected. Tube specimens with thickness of 150〜700μm independent of substrates were manufactured by dissolving out the substrate by nitric acid. It was found that Young's modulus and fracture stresses in lateral compression increased with an increase of coating thickness and those also increased by diffusion thermal treatment.
