The mechanical response of in-situ copper-chromium composite was modelled using a deformation mechanism map approach. The stresses in each phase were predicted as a function of temperature and strain rate. From this the ratio of phase stresses, and hence the degree of load transfer, was obtained. The extent of load transfer and the predicted deformation modes of the two phases were then related to the expected failure mechanisms of the composite. Three modes of composite failure were predicted. Copper-chromium in-situ composites, and pure copper, were produced by a casting and swaging route. The mechanical properties were then characterised experimentally by tensile testing. Mechanical tests confirmed that the composite showed significantly higher strength than the unreinforced material. The observed failure modes of the composite were compared with the predictions. (C) 2004 Kluwer Academic Publishers.