FRACTURE MICROMECHANISMS OF DISPERSION-ST RENGTHENED AL-AL4C3 SYSTEMS

In the presented work the change in the nature of the strain for the A l-Al4C3 system was investigated and analysed at temperatures from 20 t o 500 degrees C and strain rates from to 2.5 . 10(-5) 10(-1) to 10-(1) s(-1). At room temperatures during tensile testing the strain is cont rolled s 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 temperature s in the investigated region the principal mechanism keying the nature of the strain is the presence of dynamic recovery processes. Strain r ate influences on the fracture are analysed. The ductility values obta ined were limited, The values measured at the temperature 450 degrees C and strain rate 10(-1) s(-1) are, we suppose, the onset of the super plastic behaviour.