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 (Fe3AlCx) 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. © 1994 Chapman & Hall.