Isothermal Fatigue Behavior and Residual Stress States of Mechanically Surface Treated Ti-6Al-4V: Laser Shock Peening vs. Deep Rolling

Shot Peening ◽  
2006 ◽  
pp. 447-453 ◽  
Author(s):  
Ulf Noster ◽  
Igor Altenberger ◽  
Robert O. Ritchie ◽  
Berthold Scholtes
Keyword(s):  
Residual Stress ◽  
Fatigue Behavior ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Deep Rolling ◽  
Isothermal Fatigue ◽  
Shock Peening ◽  
Stress States

Alternative Mechanical Surface Treatments for Fatigue Strength Enhancement

2005 ◽  
Vol 490-491 ◽  
pp. 328-333 ◽  
Author(s):  
I. Altenberger
Keyword(s):  
Residual Stress ◽  
High Temperature ◽  
Strain Aging ◽  
Fatigue Behavior ◽  
Laser Shock Peening ◽  
Dynamic Strain ◽  
Laser Shock ◽  
Deep Rolling ◽  
Shock Peening ◽  
Mechanical Surface

In this paper, The effects of laser-shock peening and high temperature deep rolling on nearsurface microstructures, residual stress states and fatigue behavior of various metallic materials are investigated and discussed. Similar to warm peening (shot peening at elevated temperatures), high temperature deep rolling may induce several favourable effects, especially in ferritic steels, where dynamic strain aging by carbon atoms can be exploited as a major strengthening mechanism. But also in materials without ‚classical‘ strain aging high temperature deep rolling is effective in improving the fatigue behaviour by inducing favourable, e.g. precipitation-hardened, nearsurface microstructures. As a consequence, these modified near-surface microstructures directly alter the thermal and mechanical relaxation behaviour of residual stresses. Laser-shock peening is already used in the aircraft industry (as a mechanical surface treatment for fan-blades) and owes its benefial effects to deep layers of compressive residual stress and work hardening and a relatively smooth surface roughness. Characteristic examples of microstructures and residual stress profiles as generated by laser-shock peening are presented. Moreover, the impact on the fatigue behavior of steels and a titanium alloy is outlined and discussed.

Effect of laser shock peening on residual stress, microstructure and fatigue behavior of ATI 718Plus alloy

2017 ◽  
Vol 102 ◽  
pp. 121-134 ◽  
Author(s):  
Micheal Kattoura ◽  
Seetha Ramaiah Mannava ◽  
Dong Qian ◽  
Vijay K. Vasudevan
Keyword(s):  
Residual Stress ◽  
Fatigue Behavior ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Shock Peening

scholarly journals Laser Shock Peening of SiCp/2009Al Composites: Microstructural Evolution, Residual Stress and Fatigue Behavior

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1082
Author(s):  
Rujian Sun ◽  
Ziwen Cao ◽  
Yongxin Zhang ◽  
Hepeng Zhang ◽  
Yingwei Yu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Fatigue Behavior ◽  
Base Material ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Bending Fatigue ◽  
Three Point Bending ◽  
Modification Technique ◽  
Shock Peening ◽  
Sic Particle

SiC particle reinforced aluminum alloy has a wide application in the aerospace industries. In this study, laser shock peening (LSP), an advanced surface modification technique, was employed for SiCp/2009Al composite to reveal its microstructure, microhardness and residual stress evolution. After peening, high densities of dislocations were induced in the aluminum substrate, and stacking faults were introduced into the SiC particle. The microhardness was increased from 155–170 HV to 170–185 HV, with an affected depth of more than 1.5 mm. Compressive residual stresses of more than 200 MPa were introduced. The three-point bending fatigue of the base material, laser peened and milled after laser peened specimens with artificial crack notch fabricated by a femtosecond laser was investigated. The average fatigue lives of laser peened and milled after laser peened specimens were increased by up to 10.60 and 2.66 times, compared with the base material. This combined fundamental and application-based research seeks to comprehensively explore the applicability of LSP on metal matrix composite.

Fatigue Life Recovery via Laser Shock Peening in Mechanically Damaged Aluminium Sheet; Experiments and Prediction Models

2014 ◽  
Vol 891-892 ◽  
pp. 980-985 ◽  
Author(s):  
Niall Smyth ◽  
Philip E. Irving
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Prediction Models ◽  
Load Cycle ◽  
Laser Shock Peening ◽  
Stress Fields ◽  
Hole Drilling ◽  
Laser Shock ◽  
Aluminium Sheet ◽  
Shock Peening

This paper reports the effectiveness of residual stress fields induced by laser shock peening (LSP) to recover pristine fatigue life. Scratches 50 and 150 μm deep with 5 μm root radii were introduced into samples of 2024-T351 aluminium sheet 2 mm thick using a diamond tipped tool. LSP was applied along the scratch in a band 5 mm wide. Residual stress fields induced were measured using incremental hole drilling. Compressive residual stress at the surface was-78 MPa increasing to-204 MPa at a depth of 220 μm. Fatigue tests were performed on peened, unpeened, pristine and scribed samples. Scratches reduced fatigue lives by factors up to 22 and LSP restored 74% of pristine life. Unpeened samples fractured at the scratches however peened samples did not fracture at the scratches but instead on the untreated rear face of the samples. Crack initiation still occurred at the root of the scribes on or close to the first load cycle in both peened and unpeened samples. In peened samples the crack at the root of the scribe did not progress to failure, suggesting that residual stress did not affect initiation behaviour but instead FCGR. A residual stress model is presented to predict crack behaviour in peened samples.

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