Towards robust polishing strategies for moulds and dies

This paper summarises several experiments performed in order to increase the knowledge about the polishing process (e.g. to better understand the origins of different defect structures) and to develop new polishing strategies for dies and moulds with high demands on surface quality, i.e. glossy and ‘defect free’ surfaces. The polishing strategies are not only a help to avoid unwanted surface structures, they will also work as the base for automated polishing systems, which have several advantages compared to manual polishing; vibrating hand tools and monotonic work can be avoided, dust and noise levels as well as total process time can be reduced, and more consistent surface finishes from tool to tool can be achieved. A selection of steel samples, polished with different techniques, were analysed to study how the final surface quality was influenced by e.g. the process route, the degree of purity and the microstructure. The surface quality was here represented by roughness values and SEM-images. It could be concluded that the degree of homogeneity and the purity level of the steel materials were crucial to final surface qualities; the lower amount of inclusions, the better the surface quality. Further, a classification of occurred defect structures made