Microstructure and mechanical strength of Ti3AlC2 joints bonded using oxides as interlayer

Abstract

Abstract Ti3AlC2 ceramics were successfully joined with TiO2 and Nb2O5 respectively as interlayers via solid-state diffusion bonding at 1300 °C. The joints bonded with TiO2 and Nb2O5 exhibit distinct microstructures. Two continuous thin Al2O3 oxidation layers with a thickness around 1 μm were formed in the joints bonded with TiO2. Between the oxidation layers there exists a dense oxycarbide (TiC1-xOx) layer. For the joint bonded with Nb2O5, a dense bonding layer with Nb2AlC and Nb4AlC3 grains surrounded by thin Al2O3 oxidation layers at the grain boundaries were obtained. The shear strength of the final joints shows clear dependences on both the thickness and microstructure of the joints. Smaller joint thickness and the microstructure with complex phases favour for higher shear strength. Those result implies that bonding with oxides is a practical and efficient method for joining Ti3AlC2.