Superplastic behaviour of a ceramic-based kappa/alpha Fe-10Al-1.9C material

Abstract

A fine microstructure has been developed in a Fe-10Al-1.9C material made from rapidly solidified powders. The compacted material had a microstructure containing about 50 vol% kappa phase (Fe3AlC x ) and 50 vol% alpha phase. The creep behaviour of the material was investigated using tension and compression change in strain rate tests and elongation to failure tests. Stress exponents of 2–3 were obtained over a wide range of strain rates, and an average activation energy for creep of 245 kJ mol–1 was determined. A maximum elongation to failure of 1120% was obtained at 900°C. The tensile ductility as a function of strain rate was found to follow the same behaviour of other ceramic materials wherein the elongation to failure decreases sharply with an increase in strain rate.