A study of the preparation and properties of dense binderless titanium carbonitride-based ceramics

摘要

In this study, the surface oxidation phenomenon of raw powders in the preparation of binderless titanium carbonitride-based ceramics was investigated, which might hinder the densification process. In order to reduce the oxidation and strengthen mutual diffusion, the micrometer-sized powder mixtures of Ti(C,N) and carbides additives, pre-alloyed (Ti,W,Mo,Ta)(C,N) solid solution powders were used. The utilization of solid solution raw powders can reduce the oxidation and promote densification effectively. In this way, the binderless ceramics with high relative density and great mechanical properties were fabricated. The hardness, transverse rapture strength and fracture toughness of materials prepared by solid solution powders were 2030 HV, 1280 MPa and 7.8 MPa m(1/2), respectively. Moreover, the obtained binderless titanium carbonitride-based ceramics were found with low friction coefficient, excellent wear and oxidation resistance. The great oxidation resistance was attributed to the formation of rutile-type oxidation products facilitated by the existence of other metal elements in the ceramics. (C) 2020 Elsevier B.V. All rights reserved.