Preparation of a novel layer-structured Ti3Al matrix composite sheet by liquid-solid reaction between Al foils and TiB/Ti composite foils

摘要

An alternative approach was successfully explored to produce fully dense Ti3Al matrix composite sheets using reaction annealing of the sandwich-structured (TiB/Ti)-Al laminates. It was noteworthy that the Ti3Al matrix composites displayed a unique multi-layered structure, composing of alternating TiB-rich layers and Ti3Al layers. Actually, TiB whiskers exhibited a layered distribution in Ti3Al layers, which was in favor of the equiaxed grain refinement in Ti3Al layers. Formation mechanism of the composites' laminated microstructure was elucidated. The multilayered TiB-Ti3Al composites showed a significant increase in plasticity while maintaining or even improving the high tensile strength. Although the fracture toughness did not reach the desired level, however it was believed that the fracture toughness should be improved by means of increasing the long-aspect ratio of TiB whiskers and the volume fraction. (C) 2016 Elsevier Ltd. All rights reserved.