Solidification microstructure of Al₂O₃ short fiber reinforced M124F composite

The tensile strength, solidification microstructure and interface in Al₂O₃f/M124F composites made by squeeze casting technique were investigated and analyzed. The results indicate that the compact structure and uniform distribution of the fibers can be achieved by squeeze casting, the tensile strength are significantly improved, and α-Al dendrite and Si phase in matrix structure are obviously refined. The analysis show that the addition of fibers have double enhancement.The intervention of high tensile-strength ceramic fiber reinforces the matrix material. The short alumina fibers retard the growth of α-Al dendrite and serve as the propitious sites for the heterogenous nucleation of Si phase during solidification, thus refining matrix microstructure and improving the mechanical properties of the composite furthermore.Interfacial products of MgAl₂O₄ are not observed between fiber and matrix.