Investigation of thin layers deposited by two PVD techniques on high speed steel produced by powder metallurgy

摘要

This study was intended to investigate the properties and cutting performance with thin layers applied by two PVD techniques. PVD techniques ARC and LARC were used for the deposition of thin coatings onto cutting tools prepared by powder metallurgy. Advanced types of layers - monolayer AlTiCrN and nanocomposite type of nc-AlTiN/Si_3N_4 layer - were analyzed by standard techniques for surface status and quality assessment - roughness, hardness, layer thickness, chemical composition by GDOES, tribo-logical properties at room and elevated temperature. Durability testing of the cutting tools was carried out according to the standard ISO 3685-1999. The nanocomposite nc-AlTiN/Si_3N_4 layer achieved lower roughness when compared to monolayer AlTiCrN which leads to the achievement of higher hardness and better layer quality. The HV0.5 hardness values were ~26 GPa. The results showed a 2-3-times longer durability of the cutting tools in comparison with equivalent uncoated PM and traditional materials. The deposited coatings contributed to the improvement of their durability.