Laser polishing techniques for roughness improvement on metallic surfaces

Work presented here shows the results of the laser polishing technique. Laser polishing is based on the vapourisation/melting of a microlayer that only affects to the peaks of the surface topography. This process is being used in optical lens and silicon wafers, however the application of this technique on metal surfaces is not significant yet. Laser polishing is a non-contact finishing technique and no tool is required. In addition, it is easy to automate and implement in a commercial machine. Thus, the objective is to develop a metal surface polishing technology focused on die and mould industry. Several tests are presented on different surfaces for two different materials: a 52 HRC DIN 1.2344 tool steel and a laser sintered alloy denominated Laser Form ST100^®. Tested surfaces present different initial roughness (ranging from 2.3 to 1.7 gm Ra). After laser polishing tests, high roughness reductions were achieved in all cases.