Journal Article
Development of Al-Mn-Cu-Mg Brazing Sheet Core Alloys for Automotive Heat Exchanger Units for Service at High Temperatures
2015-04-14
2015-01-0515
New aluminum alloys, based on a commercial Al-Mn-Cu brazing sheet core alloy, with increasing alloying element Mg up to 2 wt.%, have been developed for automotive heat exchanger units in service at above 200°C. The new Al-Mn-Cu-Mg alloys are to be used as the core material in brazing sheets for vacuum and nickel brazing technologies. They were DC cast to 3.75″ lab sized ingots, scalped, re-heated to 520°C, hot rolled to 4.8 - 5mm, and cold rolled down to a final gauge of 1mm. It has been demonstrated by various mechanical and corrosion testing that Mg contributes a strong solid solution hardening effect at both the room and elevated temperatures, without damaging the other mechanical properties or corrosion resistance. Hence the alloys with 1 - 2 wt.% Mg are able to maintain high yield strength above 60 MPa at 200 - 300°C, with no reduction in formability and very limited decrease in corrosion resistance.
