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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Aluminium and zinc alloy
2002
Sir,
Please inform what will be the benefit or loss if 10% Zinc is added to Aluminium for die casting, e.g., on it's colour, surface finish, defects, corrosion resistance, etc.
Thanks and regards,
- Moradabad, UP, India
2002
Do you mean a) 90% Al-10% Zn alloy or b) the addition of 10% Zn to an existing alloy? You can begin by checking the phase equilibria for feasibility of casting, but for further data, visit specialized websites such as those given below.
Composition a) would be problemsome due to segregation during the solidification and the high vapor pressure of Zn some 200+ C above its melting point. Compare the Al-Zn phase diagram (http://klara.met.kth.se/pd/element/Al-Zn.html) with that of the Al-Si diagram (http://klara.met.kth.se/pd/element/Al-Si.html). Cooling an Al-10%Zn liquid will result in an Al-rich solid and a Zn-enriched liquid, possibly resulting in Zn vapor bubbles and hence porosity. The final liquid temperature and composition would be a function of cooling rate. The Al-10%Si composition, near that of many commercial diecast alloys, is near a eutectic point, allowing a lower liquid temperature and assuring a fairly constant liquid composition during solidification.
Composition(s) b). Consider funding some research at the Advanced Casting Research Center at Worcester Polytechnic Institute. ˇRecent research on the interactions between alloy chemistry, microstructure and performance in die-casting alloys was funded by a $500,000 grant from the Department of Energy and overseen by the Cast Metal Coalition and the North American Die Casting Association (NADCA). The work culminated in the book Microstructures and Properties of Aluminum Die Casting Alloys, published by NADCA.ü [at least buy the book!]
They have a current research project "Development of an Electronic Data Base for Rapid Selection of Aluminum Die Casting Alloys" with the goals of predicting alloy chemistry required for given properties and the converse of predicting properties for a given alloy.
(http://www.wpi.edu/Academics/Research/ACRC/Research/database.html)
Also, The North American Die Casting Association
(http://www.diecasting.org/) has useful and interesting information on their website, e.g., alloy compositions and ˇA Study in Aluminum Die Casting Design Electronics Housing for the F/A18.
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
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ALUMINIUM ALLOY 3003. What would happen if I where to add 1.5% Zinc in this alloy.Especially in the context of producing flat sheet for food containers.
NASH SinghPROD MANAGER - Durban,South africa
2007
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