Thermomechanical processing of (TiB + TiC)/Ti matrix composites and effects on microstructure and tensile properties

In the paper, 2.5 vol% (TiB + TiC)/Ti composite has been fabricated by in situ casting route. 1-D forging and subsequent multistep rolling in (α + β) phase field are conducted on the as-cast composite and, accordingly, the matrix microstructure is significantly refined, and the distribution uniformity of reinforcements is greatly improved. The tensile properties of the composites with different processing states are tested at room temperature (RT), 600 and 700 °C. The results indicate that thermomechanical processing (TMP) can drastically improve strength and elongation of the as-cast composite both at RT and 600 °C. As tensile temperature increases to 700 °C, the UTSs of the composites gradually reduce while the elongations of the composites are enhanced remarkably after TMP. The degradation in UTS can be related to the matrix softening and interfacial debonding at 700 °C.