Properties of laser melted MCrAlY coatings on Cu alloy substrates

Cu alloy components having a cooling structure are used under high temperature environment. And, MCrAlY coatings are applied to protect the Ni or Co alloy substrates from high temperature oxidation and corrosion. From these background, MCrAlY coating may also be applied to Cu alloy substrates. However, coating peeling tends to occur easily than Ni based alloy substrate. The cause is due to the difference between the coefficient of linear expansion of the coating and the Cu alloy substrate, that the temperature gradient occur, and that MCrAlY coating and Cu alloy substrate are physically bonded. Therefore we tried to melt bonding the MCrAlY coating and the Cu alloy substrate by the fiber laser. In this report, we show the coating structure and high temperature oxidation characteristics.