The eta phase is a tungsten-cobalt-carbon ternary compound formed by the participation of some Co atoms during the cooling process after sintering of cemented carbide. The dissolved W in Co cannot form WC. This provides the opportunity for cryogenic treatment to further promote the formation of the eta phase. potential.
Studies by Reddy et al., Gill et al., Vadivel et al., Seah et al. all believe that cryogenic treatment causes the precipitation of eta phase particles in cemented carbide. The presence of these fine carbide particles makes the material matrix more dense, stable and tough. At the same time, during the cryogenic treatment process, the originally coarse and disordered eta phase particles were reshaped into a more stable form D-22.41, 43, 4.51.
For the aforementioned cemented carbide tools, the precipitation of eta phase after cryogenic treatment can improve its hardness and wear resistance without having a great impact on toughness. Therefore, cemented carbide tools after cryogenic treatment show better cutting performance. As for the mechanism of eta phase precipitation, some studies believe that it is related to the martensitic transformation that occurs during cryogenic cooling, resulting in the formation of a phase with clusters of C atoms as the core around the defects.
Post time: Mar-06-2024
