Mechanical properties and strengthening effects of in situ (TiB+TiC)/Ti-1100 composite at elevated temperatures

Titanium matrix composites (TMCs) reinforced with ceramic particles significantly improves the specific modulus, specific strength and creep resistance of the Ti matrix. In situ TMCs were studied widely which overcome the shortcomings of pollution of reinforcements and wettability between ceramic particles and matrix. In this work, in situ (TiB+TiC)/Ti-1100 composites were prepared in a consumable vacuum furnace using the reaction between B4C and Ti. The microstructure and mechanical properties of the (TiB+TiC)/Ti-1100 composites were investigated. Mechanical properties of the (TiB+TiC)/Ti-1100 composites were evaluated by tensile tests at elevated temperatures. Compared to the homogenous Ti-1100 alloy, the yield strengths of the composites were increased to different extents, and the improvement of strength was discussed in terms of various strengthening mechanisms, which were calculated by modeling thoroughly. A model was suggested to predict yield strengths of the composite. An increase in the yield strength of the composite was indentified to be the effect of the solid solution carbon.