Direct Rolling of TiCp/Ti–6Al–4V Composite for Improved Microstructure, Mechanical Properties, and High‐Temperature Oxidation Resistance. Issue 9 (30th May 2021) - Jia, Yi
Abstract : Herein, the 5 vol% TiCp /Ti–6Al–4V composite is prepared by induction skull melting (ISM) and direct rolling in near‐β phase region. The microstructure, mechanical properties, and high‐temperature oxidation behavior of the as‐cast and as‐rolled composites are systematically investigated. The investigations of microstructure reveal that the as‐cast coarse α/β lamellar matrix microstructure is translated to refined bimodal microstructure after direct rolling. And the coarse and segregated TiC particles tend to be refined and uniformly distributed in the matrix. Tensile test results exhibit that a well‐matched strength and elongation is obtained after direct rolling. The tensile strength at room temperature (RT) and high temperature (650 °C) increases to 1291.9 and 472.5 MPa, respectively, while the as‐rolled composite maintains a good elongation of 6.7% and 26.8%, respectively. The strengthening mechanism can be attributed to grain boundary strengthening and the load‐bearing capability of TiC. Isothermal oxidation test indicates that as‐rolled composite exhibits better oxidation resistance than as‐cast composite both at 550 and 650 °C. The improved oxidation resistance is mainly a result of the significant refinement of oxides and consequently retarding the diffusion process. Abstract : Direct rolling of TiCp /Ti–6Al–4V composite and effects on the microstructure, mechanical properties, and high temperature oxidation behavior are systematically investigated. After rolling, the as‐cast coarse matrix microstructure is significantly refined and the segregated TiC particles tend to be uniformly distributed in the matrix, leading to significant improvement in the mechanical properties and high‐temperature oxidation resistance.