The Partnership for New Generation Vehicle has the goal of producing lightweight automobiles that achieve 80 mpg. To accomplish this will require liberal use of Al and Mg alloys such as AA5083 and AZ91D. The corrosion and stress corrosion of alloy AA5083 is controlled by the precipitation of the b-phase (Al3Mg2) at grain boundaries and by the precipitation of the g-phase (Mg17Al12) in AZ91D. The b-phase is anodic to the Al matrix while the g-phase is cathodic to the Mg matrix. The effects of crack propagation along grain boundaries with electrochemically active particles is a key factor in the SCC performance of these materials.
Revised: January 17, 2011 |
Published: December 31, 2000
Citation
Jones R.H., M.J. Danielson, D.R. Baer, C.F. Windisch, J.S. Vetrano, and D.J. Edwards. 2000.Stress Corrosion Cracking Issues in Light Metals for Automotive Applications. In NACE Paper #51300-01235-SG. Houston, Texas:National Association of Corrosion Engineers.PNNL-SA-33888.