Effects of laser peening treatment on high cycle fatigue properties of degassing-processed cast aluminum alloy

Laser peening without coating (LPwC) has been applied to water-immersed materials using a water-penetrable light of a Q-switched and frequency-doubled Nd:YAG laser. Compressive residual stress of several hundred MPa was introduced at the surface of the materials. High-cycle fatigue (HCF) properties were evaluated through rotating-bending or push-pull type testing for an austenitic stainless steel (SUS316L), a titanium alloy (Ti-6Al-4V) and a cast aluminum alloy (AC4CH). LPwC prolonged the fatigue lives significantly, in spite of the increase in surface roughness ascribed to the ablative interaction of laser pulses with the materials.

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Influence of Laser Peening Treatment on High-Cycle Fatigue Properties of Degassing Processed AC4CH Aluminum Alloy

Journal of the Society of Materials Science Japan ◽

10.2472/jsms.55.706 ◽

2006 ◽

Vol 55 (7) ◽

pp. 706-711 ◽

Cited By ~ 13

Author(s):

Kiyotaka MASAKI ◽

Yasuo OCHI ◽

Youhei KUMAGAI ◽

Takashi MATSUMURA ◽

Yuji SANO ◽

...

Keyword(s):

Aluminum Alloy ◽

High Cycle Fatigue ◽

Fatigue Properties ◽

Laser Peening ◽

Cycle Fatigue

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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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