Microstructure refinement mechanism of Cu–7Cr in situ composites with trace Ag

Microstructure refinement mechanism of Cu–7Cr in situ composite with trace Ag was investigated by scanning electron microscopy (SEM), telescope electron microscope (TEM), micro hardness tester (Hv), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The results show that the addition of trace Ag can promote the evolution from Cr filament to Cr particle, which results in the refinement of Cr filament with average thickness about 1 μm and Cr particle with average diameter about 0.8 μm in the Cu–7Cr–0.07Ag in situ composite. This microstructure refinement was discussed in the view of stacking fault energy and interaction intensity among the components with Cu, Cr and Ag elements. However, the addition of trace Ag exhibits the little effects on the texture and orientation of Cu–7Cr in situ composite.

► The refinement mechanism of Cu–7Cr composite with trace Ag has been studied.
► The effect of trace Ag on the hardness of Cu–7Cr composite has been analyzed.
► The interaction intensity has been analyzed for the Cu–7Cr composite with Ag.