1995 Volume 59 Issue 11 Pages 1185-1191
The chemical compatibility of reinforcements, processing and fracture characteristics of δ-Al2O3 short fiber and β-SiC whisker reinforced FeAl composites with the matrix composition of 40∼50 at%Al were examined. The β-SiC whisker does not react severely with FeAl in the temperature range below 1400 K. The FeAl matrix composites of full density are successfully fabricated by the reactive hot press sintering at 1273∼1373 K. The proportional limit of Fe-40 at%Al matrix increases slightly by the addition of δ-Al2O3 short fibers due to the extremely weak bonding at the matrix/fiber interfaces. Although the β-SiC whisker reinforced Fe-40 at%Al composites exhibits brittle fracture by the whisker addition beyond 15 vol%, the remarkable strengthening is achieved at volume fractions of 5∼10 vol%. The brittle Fe-50 at%Al matrix is hardly strengthened at room temperature by the additions of δ-Al2O3 short fibers and of β-SiC whiskers. The fracture toughness of the FeAl matrix composites reinforced with both the discontinuous fibers is reduced at higher volume fractions.
