Burnishing of PM Tool Steels Using Diamond Composite Material

摘要

Selected properties of surface layers of Vanadis 6 and Vanadis 60 steels were improved by slidediamond burnishing process. This steels are respectively classified as advanced powder metallurgy(P/M) cold work and high speed steels. The investigation focused on the using of sintered compositematerial to finishing operation on this type of steels, hardened in the case of Vanadis 60 to 62 HRC.High pressure-high temperature (HT-HP) Bridgman type apparatus was used to obtain diamondcomposite with ceramic bonding phase, namely Ti_3SiC_2. Compacts were sintered at pressure of8.0±0.2 GPa and at temperature about 1800±50 ℃ for 30 s. Subsequently their spherical shape wasformed by electrical discharge machining (EDM) treatment. Microstructure and some mechanicalproperties for diamond composite and P/M steels are presented. Surface roughness of tool steelsbefore and after burnishing is also shown. Large reduction in the surface roughness and increase ofmaterial ratio of the roughness profile were achieved.