Effects of boron addition on the microstructure and mechanical properties of (Ti,Ta)(C,N)-Co based cermets

In this work, a titanium-tantalum carbonitride based cermet, with cobalt as the binder phase and boron as a sintering additive, was developed by a mechanically induced self-sustaining reaction process using two different methodologies. The boron additive was added to prevent the formation of brittle...

Descripción completa

Detalles Bibliográficos
Autores: Chicardi, E., Gotor, F.J.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/203752
Acceso en línea:http://hdl.handle.net/10261/203752
Access Level:acceso abierto
Palabra clave:Titanium carbonitride
Cermet
Boron
Intermetallic
Binder
MSR
Powder metallurgy
Descripción
Sumario:In this work, a titanium-tantalum carbonitride based cermet, with cobalt as the binder phase and boron as a sintering additive, was developed by a mechanically induced self-sustaining reaction process using two different methodologies. The boron additive was added to prevent the formation of brittle intermetallic compounds generally formed during the liquid phase sintering step due to the excessive ceramic dissolution into the molten binder phase. A systematic study was carried out to understand the effects of boron addition on the nature of the phases, microstructure, and mechanical properties of cermets. With the boron addition, the formation of two different boride solid solutions, i.e., (Ti,Ta)B and (Ti,Ta)B, was observed. Moreover, the nature of the binder was also modified, from the (Ti,Ta)Co brittle intermetallic compound (for cermets without boron addition) to ductile and tough (Ti,Ta)Co and α-Co phases (for cermets with boron addition). These modifications caused, as a general trend, the increase of hardness and toughness in cermets.