The Effects of Direct Aging on Mechanical Properties and Corrosion Resistance of Diecast Magnesium Alloys AZ91D and AM60B

The effects of low temperature thermal processing on diecast magnesium alloys AZ91D and AM60B were studied to determine the impact of manufacturing processes such as the baking of coatings on mechanical properties and corrosion resistance. For times less than 36 hours at temperatures up to 232°C little effect was observed on mechanical strength. Exposure to temperatures above 230°C was found to decrease salt spray corrosion resistance, particularly in alloy having higher residual element content. It was concluded that processing temperatures for diecast components in alloys AZ91D and AM60B be further limited to temperatures below 150° C whenever possible to insure maximum toughness and to offer a margin of safety.