2134/15359
C. Banjongprasert
C.
Banjongprasert
Simon Hogg
Simon
Hogg
Enzo Liotti
Enzo
Liotti
Caroline Kirk
Caroline
Kirk
S.P. Thompson
S.P.
Thompson
J. Mi
J.
Mi
P.S. Grant
P.S.
Grant
Spray forming of bulk ultrafine-grained Al-Fe-Cr-Ti
Loughborough University
2014
untagged
Chemical Sciences not elsewhere classified
Mechanical Engineering
2014-07-28 12:53:57
Journal contribution
https://repository.lboro.ac.uk/articles/journal_contribution/Spray_forming_of_bulk_ultrafine-grained_Al-Fe-Cr-Ti/9394967
An Al-2.7Fe-1.9Cr-1.8Ti alloy has been spray formed in bulk and the microstructure and
properties compared with those of similar alloys produced by casting, powder aomization (PA),
and mechanical alloying (MA) routes. In PA and MA routes, a nanoscale metastable icosahedral
phase is usually formed and is known to confer high tensile strength. Unlike previous
studies of the spray forming of similar Al-based metastable phase containing alloys that were
restricted to small billets with high porosity, standard spray forming conditions were used here
to produce a ~98 pct dense 19-kg billet that was hot isostatically pressed (‘‘HIPed’’), forged,
and/or extruded. The microstructure has been investigated at all stages of processing using
scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and synchrotron
X-ray diffraction (XRD) at the Diamond Light Source. Consistent with the relatively low
cooling rate in spray forming under standard conditions, the microstructure showed no compelling
evidence for the formation of metastable icosahedral phases. Nonetheless, after downstream
processing, the spray-formed mechanical properties as a function of temperature were
very similar to both PA rapid solidification (RS) materials and those made by MA. These
aspects have been rationalized in terms of the typical phases, defects, and residual strains
produced in each process route.