Fabrication and Wear Behavior of TiCN-Based Cermets with Nano-Diamond Addition.

TiCN-based cermets have been widely used as cutting tools and wear-resistant coatings due to their excellent performance. New kinds of TiCN-based cermets that are being developed to have high performance have attracted extensive attention. In this work, TiCN-based cermets with nano-diamonds (NDs) as an additive were prepared by spark plasma sintering (SPS). The phase composition, microstructure, mechanical properties and wear behavior of the samples with different ND contents were systematically studied. The results show that a large fraction of the added nano-diamonds was transformed into graphite, while part of the diamond phase remained. The aggregation of the graphite became serious with more than 7 wt.% added nano-diamond. The relative density of the samples was approximately 87% and the hardness decreased with an increase in the added amount of nano-diamond. The average coefficient of friction of the samples ranged from 0.4 to 0.5. The graphite generated from nano-diamond lead to a deterioration in the mechanical properties of the prepared cermets and a reduction in their wear resistance. How to reduce the graphitization of diamond during the preparation of cermets should be considered in the follow-up study.