There has been growing research interest in nanocrystalline (NC) materials due to their superior strength as compared to their coarse-grained counterparts. However, most NC materials suffer deleterious grain growth at low homologous temperature or under mechanical loads. Recently, it has been shown that certain immiscible systems, such as Cu-Ta and Cu-Nb, can retain NC grains under these circumstances. The lack of miscibility, however, makes attaining these microstructural features require processing techniques that drive non-equilibrium states. Solid phase shear processing (SPP) techniques such as mechanical alloying (MA), high pressure torsion (HPT), friction stir processing (FSP), equal channel angular pressing (ECAP), shear assisted processing and extrusion (ShAPE) have been used to successfully process such NC materials and are an active area of research in materials science. In the present work, immiscible Cu-Ta/Nb alloys made using SPP techniques are studied using multimodal characterization tools to understand the microstructure property correlations.