SUPERPLASTICITY OF A Ni-28.5Al-20.4Fe INTERMETALLIC ALLOY

Our previous investigation examines the soperplastic behavior of an extruded Ni-28.5Al-20.IFe alloy. Its tensile properties were determined at temperature from 1123Kto 1323K and initial strain rates from 1.0{x 10-2s-1 to 1.04x 10-4s-1. A maximumelongation of 233K was obtained at 1123K and a strain rate Oj 5.2x 10-4s-1. Fur-thermore, microstructural features, such a8 decrease in the avempe gmin Bize afier de-formation at 85dC and 98dC the presence oj many dislocationthee gmins adjacentto grains with a high dislocation density, indicate that dynamic recrystallization hasoccuwed as an decient accotnmodation mechanism. SEM examination Of the fracturesample afier saperplastic defOrmation revealS many voids on the hecture sudece. Bycoerelating with the results Oj TEM observation, it is sopested that the soperplasticdejormation in this alloy should be controlled by a gmin boundarp sliding-based mech-anism accommodated by the movement oj dislocation and dynamic recrpstallization.