Fracture micromechanisms of strengthened Al-Al sub 4 -C sub 3 systems

In this work the change in the nature of the strain for the Al-Al sub 4 C sub 3 system was investigated and analyzed at temperatures from 20-450 deg C and strain rates from 2.510 exp -5 to 10 exp -1 s exp -1 . At room temperature during tensile testing the strain is controlled by dislocation movement and reactions. The first part of the strain is characterized by work hardening expressed by the exponent "n", the second part by the local strain in the neck. For high temperatures in the investigated region the principal mechanism keying the strain is the presence of dynamic recovery processes. Strain rate influences on fracture are analyzed. The values measured at the temperature 450 deg C and strain rate 10 exp -1 s exp -1 are, it is supposed, the onset of the superplastic behavior.