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A D V A N C E D M A T E R I A L S & P R O C E S S E S | M A R C H 2 0 1 6
2 0
Fig. 4 —
Fatigue life of research and A380 alloys after T6 heat treatment.
fatigue life reaches 10
7
cycles without
failure, the alloy passes the fatigue test.
Therefore, the research alloy passed the
fatigue test at a strain amplitude of 0.1%.
Figure 5 shows that the improved fatigue
resistance exhibited by the new alloy at
higher amplitudes was mainly attribut-
ed to the composite-like strengthening
and precipitation strengthening by tri-
aluminide phases created as a result of
Zr-V-Ti additions.
SUMMARY
CanmetMATERIALS developed a
new Al cast alloy for high-temperature
applications. Micro-additions of Ti, V,
and Zr to the Al-7Si-1Cu-0.5Mg cast
alloy led to formation of (AlSi)
x
(TiVZr)
phases that increase stability at high
temperatures, positively affecting alloy
strength. The improvement in tensile
and compressive strength is preserved
to temperatures over 200
°
C, with a
more positive effect in the T6 condition.
Moreover, creep rapture strength is
higher, and fatigue life of the new alloy
at strain amplitudes exceeding 0.1% is
substantially longer than that of A380
reference grade.
~AM&P
For more information:
Frank Czer-
winski is group leader, senior research
scientist, CanmetMATERIALS, 183 Long-
wood Rd. South, Room 259C, Hamilton,
Ontario L8P 0A5 Canada, 905.645.0887,
frank.czerwinski@canada.ca,
www.can- metmaterials.nrcan.gc.ca.
Acknowledgments
Financial support of the ecoEII
Program of Natural Resources Cana-
da and the Natural Sciences and Engi-
neering Research Council of Canada
(NSERC) is gratefully acknowledged.
The authors also thank the Innovative
Casting team from CanmetMATERIALS
for casting experiments.
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Fig. 5 —
Effect of alloying on fracture
mechanismduring cyclic loading: (a) Brittle
fracture of particles in alloy without Zr, V,
and Ti additions; (b) fracture propagation
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