Influence of Temperature on the Strength and the Ductility of Dispersion Hardened Al-Al4C3 Materials.

The high temperature behavior of dispersion hardened Al-Al//4C//3 materials was studied by tensile testing with a uniform deformation rate as well as by SEM fractography and TEM microstructural investigations at elevated temperatures the stress-strain diagrams exhibit sections of stationary creep, caused by a steady-state near-equilibrium between formation of dislocations and polygonization. The lowering of the ductility with increasing temperature is due to decreasing matrix dispersoid interface strength, resulting in formation of coarser dimples in the fracture surface.