| 摘要 |
PURPOSE:To surely prevent a thermal sprayed layer form exfoliating, by forming a groove-shaped part, having ruggedness, previously on the base material surface of a piston thereafter applying thermal spraying treatment to a ceramic material and improving close attaching strength in an interface between the base material surface of the piston and the thermal sprayed layer. CONSTITUTION:An Al alloy made piston 1 forms in the whole periphery of its nozzle part internal surface a groove-shaped part 2, having ruggedness, on the surface of a piston base material 1a. Thereafter, said piston base material 1a is cleaned by an organic solvent of acetone or the like, further a shot blast process is performed for removing oxide to a degree such that a shape of the groove-shaped part 2 is not changed. Next, said piston base material 1a is preheated, further the material 1a, after it forms a grounding thermal sprayed layer 3a by plasma thermal spraying treatment or the like, forms a ceramic thermal sprayed layer 3b by the plasma thermal spraying treatment or the like. In this way, the thermal sprayed layers 3a, 3b in the piston 1 can be surely prevented from exfoliating by improbing close attaching strength in an interface between the surface of the piston base material 1a and the thermal sprayed layers 3a, 3b. |
