Laser cladding of Co-based hardfacing on Cu substrate

Abstract

Cu substrates were subjected to laser cladding with Triballoy 66 SNF by means of a CW-CO₂ laser, preceded by the deposition of an intermediate layer containing Cu-Ni-B-Si for improving the energy coupling between the laser radiation and the substrate. The intermediate layer is copper-rich close to the substrate and poor in copper at a distance from it. In the clad itself there is no copper. The matrix of the coating is βCo, because alloying with Mo, Cr, and Si, in combination with rapid cooling, prevented its transformation to α-Co. Part of the structure is equiaxial because of undercooling, the balance is dendritic, which is typical of laser cladding