Abstract:The mechanism of the tension and fracture of 2024Al alloy at semi-solid were theoretically and experimentally investigated, with the isothermal tension of 2024Al alloy at semi-solid state as an example. Results of theoretical and experimental analysis show that the tensile deformation of 2024Al alloy at semi-solid state is achieved by the relative sliding of grains and the deformation of liquid membrane under tensile stress. The relative sliding of grains is mainly accommodated by the nucleation and growth of cavities under tensile stress. A cavity will nucleate in the region with the largest hydrostatic stress at first and then grow along preferential grain boundaries, leading to the final fracture of specimen along grain boundaries.

Key words: semi-solid; tension; 2024Al; grain relative sliding