Microstructure of Cu-Cr in-situ composites prepared by high gradient unidirectional solidification horizontal continuous casting and its process

We have developed a high gradient unidirectional solidification horizontal continuous casting apparatus to investigate the preparation process of Cu-Cr in-situ composites. It is revealed that inter-matching among parameters, including glory-hole temperature, cooling intensity and drawn velocity, has the significant effects not only on the control of liquid-solid zone but also on the surface quality and internal unidirectional structure of the Cu-Cr bar. With the drawn velocity keeping 245 μm/s, the microstructure is composed of an eutectic (α + β) phase and primary α phase, in which the eutectic (α + β) phase is parallel to primary α phase, uniformly arranged along axial direction with the continuous fibres, while primary α phase exhibits cellular character at a low drawn velocity, restrained by thermal flow in growth direction.