Microstructure of XD™ Ti-6Al/TiC composites

XD(TM) method has been used to prepare TIC particles reinforced titanium composites. The phases constitute and microstructure of the Ti-6AI/TiC composites have been investigated by XRD and SEM. The lattice parameter value of TiC calculated from the XRD pattern has indicated that there exists carbon deficiency in TIG. The microstructure observed by SEM has shown that TIC is of dendritical and spherical morphology, which quite different from that of the TIC in AI/TIC master alloy. In macrostructure, the TIC particles homogeneously distribute in the matrix, but the spherical TIC mainly segregate at the grain boundary, especially at the triangle grain boundary. Microstructure of the interface has also been observed by TEM and HTEM. No reaction product has been found in the interface, but a C atom diffusion layer was determined by energy spectrum diffraction and observed by HREM image of interface microstructure. Although no definite crystallographic relationship can be defined, a orientation relationship of [01 (1) over bar0](Ti)//[011](TIC) has been obtained. (C) 2000 Kluwer Academic Publishers.