Paper number 857

THE FORMATION OF SOLID SOLUTION BAND AT THE SURFACE OF TI(CN)-BASED CERMETS

Y. J. Park, S. W. Kim, and S. Kang

School of Materials Science & Engineering
Seoul National Univ., Seoul 151-742 Korea

Summary

Ti(CN) is a well-known substrate material for cutting tool applications. It provides attractive mechanical properties, including excellent strength, hardness, and high temperature stability. In addition, the formation of a solid solution layer at the cermet surface enhances toughness, resulting in improved cutting performance. Experiments were carried out in order to elucidate the influence of secondary carbides and various atmospheric conditions on the formation of the solid solution band. TaC and WC were used as additives to Ti(CN)-Ni-Co system, and were processed in vacuum, various nitrogen pressure(2 torr~200 torr) and a carbon atmosphere. It was found that the addition of TaC facilitated band formation while the WC-containing system did not exhibit the band readily. Of various processing atmospheres, vacuum conditions gave rise to the band effectively by dissolving Ti(CN) near the sample surface.

Keywords

Ti(CN), denitrification, solid solution band, material transportation.