Microstructure to strain and fracture correlation of dispersion strengthened Al-Al sub 4 C sub 3 systems

In the presented work the differences in plasticity and fracture micromechanism were investigated and analyzed in the Al-Al sub 4 C sub 3 system with 4 vol.% of Al sub 4 C sub 3 by tensile testing at 450 deg C and two strain rates. At high strain rate 10 exp -1 s exp -1 a superplastic-like behavior has been observed, showing large uniform strain. The microstructure is polygonized, the fracture is transcrystalline, ductile with deep dimples, initialized on the inter-phase surfaces between the matrix and dispersed particle. At low strain rate 2.5mult10 exp -5 s exp -1 the microstructure is partly recrystallized. The deformation goes by slips on grain boundaries and accommodation of dislocation creep. The fractures are intercrystalline with initiation of cracking on grain boundaries, supposedly in triple points.