SUPERPLASTIC BEHAVIOR OF A CERAMIC-BASED KAPPA-ALPHA-FE-10AL-1.9C MATERIAL

A fine microstructure has been developed in a Fe-10Al-1.9C material ma de from rapidly solidified powders. The compacted material had a micro structure containing about 50 vol% kappa phase (Fe3AlC(x)) and 50 vol% alpha phase. The creep behaviour of the material was investigated usi ng tension and compression change in strain rate tests and elongation to failure tests. Stress exponents of 2-3 were obtained over a wide ra nge 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-degrees-C. The tensile ductility as a function of str ain rate was found to follow the same behaviour of other ceramic mater ials wherein the elongation to failure decreases sharply with an incre ase in strain rate.