Influences of tungsten and molybdenum additions on microstructure and mechanical properties of Fe3Al based alloys

Abstract

The influences of tungsten and molybdenum additions on the microstructure and mechanical properties of Fe3Al based alloys have been studied. The results indicate that the macrostructure of base alloy Fe - 28Al- 4Cr (at.-%) is comprised of coarse columnar grains, which have a detrimental effect on the later hot working of the ingot. After combined additions of tungsten and molybdenum, the cast structure of the ingots change significantly and consist of finer equiaxed grains. This macrostructure results in a great improvement in hot workability. Although the high temperature (HT) tensile and creep properties of Fe3Al alloys can be improved in varying degrees by additions of various amounts of tungsten or molybdenum, respectively, the best effect in improving HT mechanical properties is achieved through combined additions of small amounts of tungsten and molybdenum to the Fe -28Al- 4Cr alloy.