Layered composite of solidified TiC-TiB₂ ceramic to Ti-6Al-4V alloy achieved by fusion bonding

By introduction of Ti-6Al-4V plate at the bottom of combustion system in high-gravity field,fusion bonding of TiC-TiB₂ ceramic to Ti-6Al-4V alloy was achieved. The solidified TiC-TiB₂ ceramic with fine grains was prepared by combustion synthesis. Furthermore,the ceramic to titanium layered composite with chemical composition gradient was obtained. The microstructure of fusion bonding of TiC-TiB₂ ceramic to Ti-6Al-4V alloy indicates that,the presence of chemical reaction in explosive combustion and the subsequent thermal vacuum induced by liquid products in high-gravity field make Ti alloy partially fused. Then atomic inter-diffusion occurs spontaneously between liquid ceramic and molten Ti alloy,resulting in the achievement of the joint. Microstructure analysis shows that in the bonding joint,titanium riched carbides are distributed homogeneously with fine TiB₂ grains embedded in the matrix of Ti alloy. Shear strength of 450 MPa±35 MPa is achieved between the ceramic and Ti alloy. Vickers hardness decreases linearly from the ceramic to Ti alloy.