High speed nanoindentation aided correlative study between local mechanical properties and chemical segregation in equiatomic MoNb and MoNbTi alloys

Chemical segregation at various length scales directly impacts the material behaviour during service, wherein homogeneous response is mostly desired. Our recent efforts on development of equiatomic MoNb and MoNbTi alloys have indicated propensity for chemical segregation that in turn influences the mechanical properties. In this regard, recent advances in high speed nanoindentation mapping have demonstrated the ability to accurately measure mechanical properties at the micrometer length scale. In this work, we extend this capability to establish a quantitative link between the local chemistry measured via energy dispersive spectroscopy (EDS) and nanoindentation mapping for as-cast and heat treated equiatomic MoNb and MoNbTi alloys. Excellent correlation between chemical composition and hardness is observed. This work provides a simple framework to study the effect of chemical segregation on the local mechanical properties of multi-principal element alloys, which can be gainfully used to tailor the microstructure and properties of these alloys. Graphical Abstract Correlation between chemical segregation and mechanical properties