MICROMECHANISMS OF FRACTURE OF MAGNESIUM BASED COMPOSITE AFTER SUPERPLASTIC DEFORMATION

摘要

The micromechanisms of fracture of AZ61 + 1 wt. % Al2O3 composite inthe zone of superplastic deformation was analysed and quantified in thiswork. The specimens were tested at temperature of 200°C at differentstrain rates. Changing the strain rate, from 1x10-2 s-1 to 1x10-4 s-1, asignificant growth of ductility was observed. At maximum value ofsuperplasticity the fracture was transcrystalline ductile with dimples oftwo size categories. Based on the statistical analysis of fracturemicromechanisms at the elevated temperature and strain rates of 10-0–1x10-4 s-1 hyperbolic dependency was depicted according to Gurland –Plateau theory.