Microstructural evolution in an ultra-fine YAl2p reinforced Mg-14Li-3Al composite during warm-rolling

The YAl2p/MgLiAl composite prepared by stir casting was initially forged and then rolled at 200 °C to different thicknesses. The microstructural evolution in the composite during warm rolling was investigated by using transmission electron microscope (TEM). It is found that increasing rolling reduction is conducive to the uniform distribution and refinement of the YAl2 particles. The rolling deformation promoted the precipitation of an α phase, and the α precipitate is semi-coherent to the matrix with an orientation relationship to the β matrix as: (0002)α‖(110)β. In addition, many nano-sized YAl particles with a cubic shape were found in the matrix of the composite with a high rolling reduction due to the diffusion of Y from YAl2 to the matrix, which reacted with the Al in the matrix during warm rolling.