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Aluminum ADC12 okay for food?

2007

HI,
I AM DOING RESEARCH FOR SCHOOL, AND I NEED TO FIND OUT IF ALUMINUM ADC12 IS GOOD FOR FOOD AND TO BE USED FOR A HEATER EXCHANGER (LET'S SAY FOR A ESPRESSO MAKER)

I TRIED TO LOOK FOR THAT INFORMATION IN DIFFERENT WEBSITES, BUT SO FAR I HAD NO LUCK.

I AM LOOKING FORWARD TO HEARING FROM YOU.

Gladys Loa
Research and development - FLORIDA

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ADC 12 is a Japanese die casting alloy similar to AA 384, see letter 43432 for composition. Two reasons why it may be a poor choice of alloy:
1) Due to its copper & silicon alloying content, it will darken in alkaline cleaners (these aren't recommended for aluminum, but get used, anyway).
2) Low thermal conductivity: 92 W/m-K (for 384) vs. 200 W/m-K for 5005 (a common food utensil alloy, less prone to staining). Values from MatWeb: https://www.matweb.com

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2007

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September 16, 2009

I would not worry about the thermal conductivity as that is a minor characteristic to worry about. Copper bearing alloys are subject to corrosion. The alloy may initially darken, but then will proceed to corrode. Additionally, ADC12 could contain minor amounts of lead as an impurity. The content could be above that allowed by the FDA for food processing equipment.
5000 series wrought alloys (sheet, plate etc.) are aluminum-magnesium alloys. They do not contain copper or have lead as an impurity. Unfortunately they are not casting alloys.
514.2, 518,2, 535.2 are aluminum-magnesium casting alloys that have been used in making food processing equipment. As with the wrought alloys, they contain little or no copper and no lead.

Brian Cochran
- Wabash, Indiana