Abstract
Alumina ceramics was coated on mild steel by a detonation gun with different quantities of detonation gas, and the residual stress in the coated film was measured by using the X-ray diffraction from the (844) plane of γ-alumina by Cu-Kα radiation. The mechanical Young's modulus increased with decreasing amount of cracks and pores in the coated film made under a larger quantity of detonation gas. The X-ray Young's modulus was larger than the mechanical one because the strain measured by X-rays was the average of crystalline phases. The residual stress measured by X-rays was tension and distributed uniformly in the coated film. The tensile residual stress was smaller for the coat made with larger gas quantity. It was rather insensitive to the film thickness and also to the surface grinding.
