Effect of hot extrusion on structure and properties of YAl_2p/Mg-14Li-3Al composites

YAl_2p/Mg-14Li-3Al composites with different volume fraction were fabricated by stir casting, and then the as-cast ingots were extruded as composite thin-walled tubes with the defined experimental parameters. Effects of hot extrusion deformation on microstructure and mechanical properties of YAl_2p/Mg-14Li-3Al composites were investigated by optical microscope, scanning electronic microscope, tensile tests and so on. The results show that hot extrusion deformation can effectively improve the YAl_2p distribution and the mechanical properties of the composites. In addition, the grains of matrix are significantly refined after hot extrusion. For as-extruded YAl_2p/Mg-14Li-3Al composites with volume fraction of 1%, compared with as-cast condition, the tensile strength and the yield strength are both improved by over 60%, and the ductility is improved. In the process of hot extrusion, the extrusion pressure peak of the composite is improved slightly compared with Mg-14Li-3Al alloy, and the time of the peak pressure of the composite lags behind the alloy.