Analyses of the microstructure and fracture morphology of directionally solidified Cu-Cr in-situ composites

The influences of solidification methods and solidification rates on the microstructure of Cu-Cr in-situ composites were studied. The fracture morphology was observed and the mechanism of the fracture was analyzed. The results show that the structure of the composites consists of α(Cu) matrix phase and fiber-like (α+β) eutectics alternately. With the increase of solidification rate, (α+β) eutectics are distributed evenly and regularly and the boundaries of crystal in transverse direction reduce. The fracture morphology shows that the fracture of eutectic as reinforced phase is the critical factor for the fracture of Cu-Cr in-situ composites.