Powder metallurgy viability to produce a refractory MoNbTiW multi principal component alloy

Full text: Multi-principal component alloys were designated as 'high-entropy alloys' (HEAs) where involves merely the mixing of multiple elements in an equimolar or near equimolar composition. A second group has been investigated and it is designated as compositionally complex alloys (CCA), because they violate some definitions for high entropy alloys. Multi-principal components have not obligation to be constituted by five or more main elements. Also, a high entropy is not commonly exhibited. On the other hand, they often exhibit a small number of phases, caused partly by high entropy effects. With this context, the refractory high entropy alloys are favorable materials to high temperature applications. In general, it has excellent mechanical properties, which induces to a potential replacement with superalloys. However, their high melting point leads to processing problems when technique such as arc melting is used. Based on this context, this study aims to evaluate the possibility to manufacture the refractory multi-principal elements alloy MoNbTiW by using a powder metallurgy route. Xray diffraction, densification, optical and scanning microscopy, microhardness and compression tests and techniques are used to characterize the samples examined. Preliminary results suggest that the heat treatment at 1250°C for 6 h provide a mix between MoNbTi and W particles. Experimental results of microhardness and ultimate compressive strength of about 241 (± 30) HV and 460 (± 20) MPa are attained, respectively. (author)