Compressive Stress Retention Characteristics of High Pressure Die Casting Magnesium Alloys

A laboratory test procedure and evaluation methodology has been developed to simulate stress and strain conditions as encountered in thermo-cycled automotive powertrain fastening systems. The material characteristics obtained have been designated “compressive stress retention”. As cast coupons in two magnesium alloys and an aluminum alloy were applied loads up to 115% of the published tensile yield strength for each alloy, and were subjected to temperatures up to 175°C, for different periods of time until completing 2000 hours.

The laboratory procedure and the resultant “compressive stress retention” data are reported here for magnesium alloys AE42X1 and AZ91D as influenced by temperature, stress, geometry and time.