Effects of runner diameter on the mechanical strength and porosity distribution of thin section castings
This study was aimed to determine the effects of runner diameter on mechanical strength and porosity distribution pattern of thin section Al-12Si alloy castings which were casted through sand casting process. Computational fluid dynamic (CFD) modeling was used to identify the flow behavior during th...
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| Main Authors: | , , |
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| Format: | Conference or Workshop Item |
| Published: |
2007
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| Subjects: | |
| Online Access: | http://eprints.uthm.edu.my/4125/ http://eprints.uthm.edu.my/4125/1/EFFECT_OF_RUNNER_DIAMETER.pdf |
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| Summary: | This study was aimed to determine the effects of runner diameter on mechanical
strength and porosity distribution pattern of thin section Al-12Si alloy castings
which were casted through sand casting process. Computational fluid dynamic
(CFD) modeling was used to identify the flow behavior during the filling process.
X-ray radiography test was used to examine the general distribution of defects in
the castings from different runner diameters. 3-point bending test was applied to
measure the flexure strength. The scatter of flexure strength results was
quantified by Weibull statistics. The casting defects existing on the fracture
surface of the casting specimens were observed by scanning electron microscope
(SEM). Simulation results show that predicted porosity location moved to ingate
and runner area when the size of runner diameter is increased. This gives good
agreement with experimental results, which showed that the casting product with
a larger runner diameter leads to the improvement of average flexure strength and
reduction of porosity defects. Both results support the conclusion that the use of
runner with a larger diameter size can produce casting product with more reliable
mechanical properties and fewer porosity defects. An area ratio of unity is
recommended in some cases.` |
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