Fabrication and Evaluation of Low Cost Alumina Fiber Reinforced Metal Matrices.

摘要

Silicon carbide and alumina fiber reinforced aluminum matrix composites were evaluated and compared by tensile testing, three point bend flexural testing, elevated temperature exposure, thermal cycling, and instrumented pendulum impact. It was found that the silicon carbide/aluminum provided the higher level of axial tensile strength while the alumina/aluminum was superior in transverse tension. The difference in transverse strength was mainly due to the poor fiber-matrix bond existent in the silicon carbide/aluminum as compared to the very high strength bond in the alumina/aluminum composite. A very large difference in composite impact performance was found to be affected by the differences in fiber and matrix properties. In addition, measured composite impact energy dissipation capability was related to specimen test geometry as well as the relative levels of composite tensile and shear strengths. Both composite materials were also shown to suffer significantly due to either thermal cycling (SiC/aluminum) or constant elevated temperature exposure (alumina/aluminum). (Author)