Surface Characteristics and High Cycle Fatigue Performance of Shot Peened Magnesium Alloy ZK60

The current work investigated the effect of shot peening (SP) on high cycle fatigue (HCF) behavior of the hot-extruded ZK60 magnesium alloy. SP can significantly improve the fatigue life of the ZK60 alloy. After SP at the optimum Almen intensities, the fatigue strength at 107 cycles in the as-extruded (referred to as ZK60) and the T5 aging-treated (referred to as ZK60-T5) alloys increased from 140 and 150 MPa to 180 and 195 MPa, respectively. SP led to a subsurface fatigue crack nucleation in both ZK60 and ZK60-T5 alloys. The mechanism by which the compressive residual stress induced by shot peening results in the improvement of fatigue performance for ZK60 and ZK60-T5 alloys was discussed.

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Smooth and notched fatigue performance of aging treated and shot peened ZK60 magnesium alloy

Journal of Materials Research ◽

10.1557/jmr.2010.0173 ◽

2010 ◽

Vol 25 (7) ◽

pp. 1375-1387 ◽

Cited By ~ 3

Author(s):

Wen-Cai Liu ◽

Jie Dong ◽

Ping Zhang ◽

Xing-Wei Zheng ◽

Wen-Jiang Ding ◽

...

Keyword(s):

Magnesium Alloy ◽

Compressive Residual Stress ◽

High Cycle Fatigue ◽

Fatigue Performance ◽

Fatigue Properties ◽

Cycle Fatigue ◽

Notched Specimen ◽

Notched Specimens ◽

Zk60 Alloy ◽

Zk60 Magnesium Alloy

The influence of shot peening (SP) on high cycle fatigue (HCF) performance of smooth and notched specimens of hot-extruded ZK60 magnesium alloy was investigated and compared to that of hot-extruded and T5 aging-treated ZK60 magnesium alloy referred to as ZK60-T5. The increases in fatigue properties at the optimum Almen intensities were found to depend on the material states. In contrast to ZK60 alloy, higher smooth and notched fatigue properties for both unpeened and peened specimens were observed for ZK60-T5 alloy. Meanwhile, the improvement of fatigue life for notched specimen by SP was much more than that for the smooth specimen. The mechanism by which the compressive residual stress induced by SP resulted in the improvement of fatigue performance of smooth and notched specimens for ZK60 and ZK60-T5 alloys was discussed.

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Crystal Plasticity Modeling of Laser Peening Effects on Tensile and High Cycle Fatigue Properties of 2024-T351 Aluminum Alloy

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4050308 ◽

2021 ◽

Vol 143 (7) ◽

Author(s):

Maziar Toursangsaraki ◽

Huamiao Wang ◽

Yongxiang Hu ◽

Dhandapanik Karthik

Keyword(s):

Residual Stresses ◽

Crystal Plasticity ◽

High Cycle Fatigue ◽

Driving Forces ◽

Crack Nucleation ◽

Fatigue Properties ◽

Laser Peening ◽

Cycle Fatigue ◽

Fatigue Crack Nucleation ◽

Near Surface

Abstract This study aims to model the effects of multiple laser peening (LP) on the mechanical properties of AA2024-T351 by including the material microstructure and residual stresses using the crystal plasticity finite element method (CPFEM). In this approach, the LP-induced compressive residual stress distribution is modeled through the insertion of the Eigenstrains as a function of depth, which is calibrated by the X-ray measured residual stresses. The simulated enhancement in the tensile properties after LP, caused by the formation of a near-surface work-hardened layer, fits the experimentally obtained tensile curves. The model calculated fatigue indicator parameters (FIPs) under the following cyclic loading application show a decrease in the near-surface driving forces for the crystal slip deformation after the insertion of the Eigenstrains. This leads to a higher high cycle fatigue (HCF) resistance and the possible transformation of sensitive locations for fatigue failure further to the depth after LP. Experimental observations on the enhancement in the HCF life, along with the relocation of fatigue crack nucleation sites further to the depth, reveal the improvement in the HCF properties due to the LP process and validate the numerical approach.

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