The Effect of Different Cooling Rates on Grain Size, Second Phase Morphology, Microstructure, Wetting Angle and Corrosion of Aluminum-Silicon Alloys
Mentor 1
Pradeep Rohatgi
Location
Union Wisconsin Room
Start Date
28-4-2017 1:30 PM
End Date
28-4-2017 4:00 PM
Description
Every year corrosion causes millions of dollars' worth of damage in the form of both the destruction of property and lost productivity. Aluminum silicon alloys represent an interesting solution to these challenges due to it being both corrosion resistant as well as light weight. The aim of this study is to determine the effect of alloy composition and surface roughness on the corrosion properties of cast aluminum-silicon alloys, the effect of water droplet size on contact angle measurements of these alloys was also investigated. The alloys used in this study included common cast aluminum alloys such as A356, A360 and A368 as well as prepared Al-Si alloys with a silicon content ranging from 5% to 50%. Samples were prepared by grinding the surface of the alloy samples to a roughness of 240 grit, 800 grit and 1 micron polish. The samples then underwent water droplet testing using a goniometer to determine hydrophilicity, before undergoing corrosion current testing to determine corrosion resistance. For samples roughened with 240 grit and 800 grit sand paper the measured contact angle showed a clear trend of decreasing with increasing silicon content. Samples prepared using 1 micron polish showed no clear trend relative to silicon content. Corrosion current tests were performed on all alloy compositions at all levels of surface roughness. Results show no clear trends of corrosion resistance relative to either surface roughness or silicon content. However, a peak in corrosion resistance was found for all degrees of surface roughness in cast aluminum alloys with a silicon content of 22%. These results show that corrosion resistance of aluminum silicon alloys can be effected by altering the amount of silicon in the alloy, further validating the usefulness of aluminum in applications where corrosion resistance and light weight are necessary.
The Effect of Different Cooling Rates on Grain Size, Second Phase Morphology, Microstructure, Wetting Angle and Corrosion of Aluminum-Silicon Alloys
Union Wisconsin Room
Every year corrosion causes millions of dollars' worth of damage in the form of both the destruction of property and lost productivity. Aluminum silicon alloys represent an interesting solution to these challenges due to it being both corrosion resistant as well as light weight. The aim of this study is to determine the effect of alloy composition and surface roughness on the corrosion properties of cast aluminum-silicon alloys, the effect of water droplet size on contact angle measurements of these alloys was also investigated. The alloys used in this study included common cast aluminum alloys such as A356, A360 and A368 as well as prepared Al-Si alloys with a silicon content ranging from 5% to 50%. Samples were prepared by grinding the surface of the alloy samples to a roughness of 240 grit, 800 grit and 1 micron polish. The samples then underwent water droplet testing using a goniometer to determine hydrophilicity, before undergoing corrosion current testing to determine corrosion resistance. For samples roughened with 240 grit and 800 grit sand paper the measured contact angle showed a clear trend of decreasing with increasing silicon content. Samples prepared using 1 micron polish showed no clear trend relative to silicon content. Corrosion current tests were performed on all alloy compositions at all levels of surface roughness. Results show no clear trends of corrosion resistance relative to either surface roughness or silicon content. However, a peak in corrosion resistance was found for all degrees of surface roughness in cast aluminum alloys with a silicon content of 22%. These results show that corrosion resistance of aluminum silicon alloys can be effected by altering the amount of silicon in the alloy, further validating the usefulness of aluminum in applications where corrosion resistance and light weight are necessary.
