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.

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

Laser Shock Peening on a 6056-T4 Aluminium Alloy for Airframe Applications

2014 ◽  
Vol 891-892 ◽  
pp. 974-979 ◽  
Author(s):  
Daniel Glaser ◽  
Claudia Polese ◽  
Rachana D. Bedekar ◽  
Jasper Plaisier ◽  
Sisa Pityana ◽  
...  
Keyword(s):  
Residual Stress ◽  
Laser Pulse ◽  
Fatigue Tests ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
X Ray Diffraction ◽  
Bending Fatigue ◽  
Pulse Density ◽  
Shock Peening ◽  
Compressive Residual Stresses

Laser Shock Peening (LSP) is a material enhancement process used to introduce compressive residual stresses in metallic components. This investigation explored the effects of different combinations of LSP parameters, such as irradiance (GW/cm2) and laser pulse density (spots/mm2), on 3.2 mm thick AA6056-T4 samples, for integral airframe applications. The most significant effects that are introduced by LSP without a protective coating include residual stress and surface roughness, since each laser pulse vaporizes the surface layer of the target. Each of these effects was quantified, whereby residual stress analysis was performed using X-ray diffraction with synchrotron radiation. A series of fully reversed bending fatigue tests was conducted, in order to evaluate fatigue performance enhancements with the aim of identifying LSP parameter influence. Improvement in fatigue life was demonstrated, and failure of samples at the boundary of the LSP treatment was attributed to a balancing tensile residual stress.

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.

Study on Very-High-Cycle-Fatigue Property of Aero-Engine Blades Based on Subcomponent Specimen

2015 ◽  
Vol 664 ◽  
pp. 87-95
Author(s):  
Sheng Bo Jiao ◽  
Li Cheng ◽  
Quan Tong Li ◽  
Xiao Wei Li
Keyword(s):  
Fatigue Behavior ◽  
Fatigue Property ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Bending Fatigue ◽  
Surface Strengthening ◽  
Testing Method ◽  
Aero Engine ◽  
Shock Peening ◽  
Very High

The cyclic load number of aero-engine blade during its service life is very likely beyond 107, which is regarded as the conventional fatigue limit. Moreover, surface strengthening is very often used in the manufacturing process of blade. The conventional testing method in the VHCF regime cannot exactly reflect the stress state of the blade, including the mechanism of crack initiation. To study the fatigue behavior and effects of laser shock peening, a kind of bending fatigue subcomponent specimen was designed and the laser shock peening model was established. Experiment about TC17 was accomplished by the Ulra-High Cycle bending fatigue system. It is found that the fatigue damage occurs beneath the surface and the S-N curve is continuously rather than multi-step declining in the VHCF regime. Process of surface strengthening has a significant effect on fatigue performance of TC17 titanium alloy.

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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