Fatigue strength of Magnesium Alloys AZ31 and AZ91 as a function of service temperature

The mechanical properties of the magnesium wrought alloy AZ31 and magnesium cast alloy AZ91 in the temperature range 20 degreesC less than or equal to T less than or equal to 300 degreesC are investigated for quasistatic load ing as well as for stress controlled push-pul fatigue loading. Because of t he rolling texture AZ31 exhibits a lower yield strength in compression than in tension. Characteristic examples of plastic strain amplitudes as a func tion of numbers of loading cycles are presented. Temperature dependent cycl ic creep effects are observed. Surface treatments by deep rolling lead to c haracteristic alterations of plastic strain amplitudes. However, fatigue st rength, especially at higher temperatures, can only be increased, if stabil ized near surface residual stress states and microstructures can be created .