2009 Volume 50 Issue 4 Pages 791-798
The effects of shot peening on surface characteristics and high cycle fatigue (HCF) performance of T5-treated high-strength magnesium alloy ZK60 (named after ZK60-T5) were investigated. The glass bead with an average diameter of 0.35 mm was adopted for shot peening and the Almen intensity was arranged from 0.02 to 0.40 mmN. The surface microstructure and texture of ZK60-T5 are greatly changed by shot peening, and residual compressive stress is produced in the surface deformation layer. The magnesium alloy ZK60-T5 shows a pronounced overpeening effect. A marked improvement in fatigue life is obtained at low Almen intensities, namely the fatigue strength (at 107 cycles) increases from 150 to 195 MPa at the optimum Almen intensity of 0.05 mmN. The fatigue crack nucleation site of ZK60-T5 is also found from surface regions to the subsurface.