The interest of using carbon dioxide lasers for surface modification processes has been increasing for the last years. In the present paper new possibilities of achieving a high wear - resistant surface of cutting tool materials by laser glazing are discussed.
During laser glazing a thin layer is melted and “self quenched” at a very high cooling rate. These thin surface layers have extremely fine grain sizes. But novel microstructures and metastabile really amorphous materials are possible, too. They are characterized by great hardness and high resistance against corrosion and fatigue. Two different ways of glazing cutting tools were investigated. In the first way the surface of uncoated tungsten carbide-cobalt (WC-CO) alloys is melted by a cw-CO2 laser at 2.5 kW power and self-quenched. In the second way the hard metals are specially coated by CVD to permit the formation of a metallic glass-layer of the constitution T80M20 by laser melting with a low power CO2 laser and excimer laser. Structural changes and properties of such suface-modified inserts will be discussed in the paper. In comparison with untreated coated inserts a higher hardness and better wear-properties were found in tool life tests.