Niobium carbide based materials

The use of WC, a critical raw material based phase, in combination with a potentially harmful Cobased binder drives the search for alternative substitutional materials for the high performance state-of-the-art WC-Co cemented carbide class of wear resistant materials. In this context, the present research proposal aims to develop niobium carbide (NbC) based composites with a noncobalt metallic (iron, nickel or molybdenum) binder phase as a new innovative class of ceramicmetal composite materials for wear part and cutting tool applications. Among the potential benefits are the non-hazardous ingredients, the substantially lower specific weight of NbC and the higher chemical stability of NbC in contact with steel. Based on thermodynamic modelling, different types of NbC-based cermets will be selected and processed by means of conventional pressureless sintering or fast pressure assisted densification. Microstructural and mechanical characterization will allow elucidating the processing-microstructure-properties relationships of NbC-based cermets. The tribological performance of the most promising cermets will be evaluated by means of dedicated single asperity scratch and multi-asperity abrasion testing along with real turning testing to generate the necessary property-wear relationships that would allow defining the most appropriate application field and the further application-oriented material development for these new NbC-based materials.