The effect of severe plastic deformation in a dual phase material is investigated. High pressure torsion (HPT) was applied to Cu-1%Cr-0.1%Zr (CuCr1) and Cu-43%Cr (CuCr43) alloys. The influence of applied strain and thermal treatment on the hardness, microstructure and the mutual solubility of Cu in Cr and Cr in Cu were analysed. Micro hardness measurements, optical and electron microscopy and tomographical atom probe (TAP) investigations were performed. The results show grain refinement in both alloys down to 200 nm for Cu in CuCr1 and 10 nm for Cu and Cr in CuCr43. The hardness increases significantly after deformation by a factor of 3 and 5 for CuCr1 and CuCr43 respectively when compared to the undeformed state. Additional hardening could be achieved by thermal treatments. In the alloys a supersaturated solid solution was formed. In the case of CuCr43 a maximum concentration of 16 atom% Cu in Cr could be observed by means of TAP.