Thesis Committee

Ian Baker, Ph.D. (Chair)

Francis E. Kennedy, Ph.D.

Harold J. Frost, Ph.D.

Paul R. Munroe, Ph.D.

Abstract

The quaternary alloy system FeNiMnAl with periodic microstructures has been discovered recently. Nanostructured Fe₃₀Ni₂₀Mn₂₅Al₂₅ with remarkably high yield strength (> 1.4 GPa) exhibits a periodic microstructure consisting of alternating B2 and b.c.c phase aligned along <100>. B2/f.c.c Fe₂₈Ni₁₈Mn₃₃Al₂₁ is brittle in the finely-microstructured as-cast state while displays reasonable ductility after annealing. The objective of this proposal is to investigate the wear behavior of these potentially-useful spinodal alloys. The role played by microstructures, deformation processes, contact temperature and third bodies during pin-on-disk wear tests will be determined by using a combination of state-of-the-art techniques, such as SEM, TEM, XRD, EDS and optical profilometry.

The proposed research will involve:

1. Comparing the dry sliding wear of Fe₃₀Ni₂₀Mn₂₅Al₂₅ at room temperature and elevated temperature;

2. Studying the effect of sliding velocity on the dry sliding wear of nanophase Fe₃₀Ni₂₀Mn₂₅Al₂₅ at different sliding velocities, which will result in different contact temperatures;

3. Studying the effect of the third bodies (wear debris) on the sliding wear of Fe₃₀Ni₂₀Mn₂₅Al₂₅ as the third bodies may form a mechanically mixed layer and influence the wear process;

4. Comparing wear behavior of as-cast Fe₂₈Ni₁₈Mn₃₃Al₂₁ and annealed Fe₂₈Ni₁₈Mn₃₃Al₂₁ which have significantly different microstructures and mechanical properties in order to determine the role played by the microstructures.