METAL-CERAMIC JOINING BY LASER

Within the scope of increase in cutting tools efficiency, a CW CO2 las er beam has been used for butt welding sintered tips containing cobalt and tungsten carbide to a medium carbon steel core. After optimizatio n of the laser processing conditions, full penetrating, sound and homo geneous welds are observed. Hardness is found to be nearly constant ac ross the entire weld bead cross-section. Micrographic observations in the same area show a fine dendritic microstructure microanalysis (EDS) as well as X-ray diffraction experiments reveal that dendrites contai n mainly iron and cobalt, while tungsten has segregated in the interde ndritic tone where complex (Fe - Co - W) rich carbides are likely to f orm.