Effects of laser peening on fretting wear behaviour of alloy 718 fretted against two different counterbody materials

2017 ◽  
Vol 231 (10) ◽  
pp. 1276-1288 ◽  
Author(s):  
S Anand Kumar ◽  
R Sundar ◽  
S Ganesh Sundara Raman ◽  
R Gnanamoorthy ◽  
R Kaul ◽  
...  
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Compressive Residual Stress ◽  
Tangential Force ◽  
Fretting Wear ◽  
Wear Behaviour ◽  
Laser Peening ◽  
Alloy 718 ◽  
Force Coefficient ◽  
Near Surface

This paper deals with the effects of laser peening on fretting wear behaviour of a nickel-based superalloy, alloy 718, fretted against two different counterbody materials (alumina and SAE 52100 steel). Laser peening was carried out on alloy 718. Microstructural characterization of laser peened surface was done by electron back-scattered diffraction and transmission electron microscopy. Surface roughness, nanoindentation hardness, and residual stress of both laser peened and unpeened samples were determined. Fretting wear tests were conducted on unpeened and laser peened samples using two different counterbody materials (alumina and SAE 52100 steel balls). The results show that nanocrystallites formed in the surface and near-surface regions and compressive residual stress were induced after laser peening. Hardness increased due to grain refinement at the surface and near-surface regions. There was no significant change in the surface roughness. The laser peened sample exhibited lower tangential force coefficient values compared to unpeened samples at all loads, which may be attributed to higher hardness. Samples fretted against alumina counterbody exhibited higher tangential force coefficient compared to samples fretted against steel counterbody. Owing to increased surface hardness and higher compressive residual stress, laser peened samples exhibited lower fretting wear damage compared to unpeened samples. Due to tribochemical reactions, the wear volume of unpeened and laser peened samples fretted against alumina counterbody was higher than that of the samples fretted against steel counterbody.

Influence of Surface Mechanical Attrition Treatment on Fretting Wear Behaviour of Ti-6Al-4V

2012 ◽  
Vol 463-464 ◽  
pp. 316-320 ◽  
Author(s):  
S. Anand Kumar ◽  
S. Ganesh Sundara Raman ◽  
T.S.N. Sankara Narayanan ◽  
R. Gnanamoorthy
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Tangential Force ◽  
High Hardness ◽  
Fretting Wear ◽  
Surface Mechanical Attrition Treatment ◽  
Wear Behaviour ◽  
Force Coefficient ◽  
Near Surface ◽  
Mechanical Attrition

Ti-6Al-4V alloy was subjected to surface mechanical attrition treatment (SMAT) by using SAE 52100 steel balls of 5 mm diameter for two treatment durations (30 and 60 min). SMAT resulted in the formation of nanostructured material on the surface and near surface regions, increased hardness, increased surface roughness and compressive residual stress on the surface. Treated samples exhibited lower tangential force coefficient (TFC) compared to untreated samples. Samples treated for 60 min exhibited higher grain refinement, higher hardness, lower surface roughness and higher TFC compared to the samples treated for 30 min. Fretting wear resistance of the samples treated for 30 min was higher than that of untreated samples and the samples treated for 60 min. Due to very high hardness and presumably reduced ductility, the fretting wear resistance of the samples treated for 60 min was lower than that of the untreated samples and samples treated for 30 min.

scholarly journals Improvement in Bending Strength of Silicon Nitride through Laser Peening

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 315
Author(s):  
Kazuya Saigusa ◽  
Joji Yamamoto ◽  
Koji Takahashi ◽  
Fumiaki Kumeno ◽  
Norihito Shibuya
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Silicon Nitride ◽  
Compressive Residual Stress ◽  
Bending Strength ◽  
Fracture Initiation ◽  
Laser Peening ◽  
Initiation Point

This study aimed to improve the bending strength and reliability of ceramics using laser peening (LP). In the experiment, LP without coating (LPwC) and with coating (LPC) were applied to silicon nitride (Si3N4) under various conditions. The surface roughness, residual stress, and bending strength were then measured for the non-LP, LPwC, and LPC specimens. The results show that the LPwC specimen had a greater surface roughness but introduced larger and deeper compressive residual stress when compared with the non-LP and LPC specimens. In addition, the bending strength of the LPwC specimen was higher and scatter in bending strength was less compared with the non-LP and LPC specimens. This may be attributed to the transition of the fracture initiation point from the surface to the interior of the LPwC specimen because of the compressive residual stress introduced near the surface. Thus, it was demonstrated that the application of LP is effective in improving the strength and reliability of ceramics.

Effect of the Type of Grinding Wheel on the Surface Characteristics of a Titanium Alloy with Internal Coolant Supply

2019 ◽  
Vol 825 ◽  
pp. 92-98
Author(s):  
Nakatsuka Nagatoshi ◽  
Sumito Toyokawa ◽  
Atsushi Kusakabe ◽  
Shinya Nakatsukasa ◽  
Hiroyuki Sasahara
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Silicon Carbide ◽  
Titanium Alloy ◽  
Aluminum Oxide ◽  
Compressive Residual Stress ◽  
Surface Characteristics ◽  
Grinding Wheel

The objective of this paper is to clarify the effect of grinding surface characteristics in the grinding of a titanium alloy with a coolant supply from the inner side of the grinding wheel. In this paper, we selected a white aluminum oxide (WA) vitrified bonded grinding wheel and a green silicon carbide (GC) vitrified bonded grinding wheel, and compared their grinding characteristics. As a result, in the case of the GC vitrified bonded grinding wheel, the surface roughness decreased by about 54% and the compressive residual stress increased by about 128%.

scholarly journals Fatigue Life Improvement of the High Strength Steel Welded Joints by Ultrasonic Impact Peening

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 619 ◽  
Author(s):  
Ján Lago ◽  
Libor Trško ◽  
Michal Jambor ◽  
František Nový ◽  
Otakar Bokůvka ◽  
...  
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Welded Joints ◽  
Compressive Residual Stress ◽  
High Strength ◽  
Fatigue Properties ◽  
Low Alloy Steel ◽  
Residual Stress Field ◽  
Near Surface ◽  
Life Improvement

Ultrasonic impact peening was applied on welded joints manufactured from Strenx 700 MC high strength low alloy steel with the aim to improve the fatigue properties. Three different surface treatment parameters were tested, which resulted in transformation of the near-surface tensile residual stresses in the weld metal and heat affected zone to compressive residual stress field, while maximal values from −400 MPa up to −800 MPa were reached. The highest fatigue life improvement was reached by the double peening with the 85 N contact force, where the fatigue limit for N = 108 cycles increased from 370 MPa to 410 MPa.

A Study on the Fatigue Characteristics of Al6061-T651 by Shot Peening Velocity

2006 ◽  
Vol 326-328 ◽  
pp. 1093-1096 ◽  
Author(s):  
Won Jo Park ◽  
Sun Chul Huh ◽  
Sung Ho Park
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Fatigue Life ◽  
Shot Peening ◽  
High Speed ◽  
Compressive Residual Stress ◽  
Velocity Increase ◽  
Fatigue Characteristics ◽  
Height Increase ◽  
Small Steel

Small steel ball is utilized in Shot peening process. Called “shot ball” are shot in high speed on the surface of metal. When the shot ball hit the surface, it makes plastic deformation and bounce off, that increase the fatigue life by compressive residual stress on surface. In this study, the results of observation on the tensile strength, hardness, surface roughness, compressive residual stress and fatigue life of a shot peened Al6061-T651 were obtained. Experimental results show that arc height increase tremendously by shot velocity. Also, it shows that surface roughness, hardness, compressive residual stress and fatigue life increase as shot velocity increase.

scholarly journals Effect of thermal relaxation on residual stress and microstructure in the near-surface layers of dual shot peened Inconel 625

2018 ◽  
Vol 10 (10) ◽  
pp. 168781401880053
Author(s):  
Lihong Wu ◽  
Chuanhai Jiang
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Elevated Temperatures ◽  
Thermal Relaxation ◽  
Diffraction Method ◽  
Relaxation Behavior ◽  
Inconel 625 ◽  
Surface Layers ◽  
Near Surface ◽  
Subsurface Layers

Thermal relaxation behavior of residual stress and microstructure in the near-surface layers of dual shot peened Inconel alloy 625 was investigated by X-ray diffraction method. Residual stress on the top surface layer was significantly relaxed in the first 15 min at the elevated temperatures of 500°C, 600°C, and 700°C. However, there was still high maximum compressive residual stress in subsurface layers. The relaxation behavior of residual stress has contributed to the thermally activated process. The activation enthalpy Δ H and m were calculated according to the Zener–Wert–Avrami method, the values of which were 1.59 eV and 0.4934, respectively. Microstructural evaluation revealed that it was slightly changed in the near-surface layers after various isothermal treatments. Accordingly, high level of compressive residual stress and dislocation density resulted in the retained mechanical properties of dual shot peened Inconel 625, which was discussed based on the relaxation of microstructure and microhardness.

312 Impartment of compressive residual stress on materials surface by laser peening

2006 ◽  
Vol 2006.14 (0) ◽  
pp. 167-168
Author(s):  
Yuji SANO ◽  
Koichi AKITA ◽  
Kiyotaka MASAKI ◽  
Yasuo OCHI
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Laser Peening

scholarly journals Enhancement of Fatigue Strength on SAE 1541 Steel Link Plate with Slip Ball Burnishing Technique

2020 ◽  
Vol 70 (4) ◽  
pp. 454-460
Author(s):  
K. Krishnakumar ◽  
A. Arockia Selvakumar
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Fatigue Strength ◽  
Compressive Residual Stress ◽  
Repeated Loading ◽  
Ball Burnishing ◽  
Novel Technique ◽  
Conventional Process ◽  
Chain Link ◽  
Local Plastic Deformation

This research paper describes a technique for the enhancement of the fatigue strength of the chain link plate in the drive system of a military armoured vehicle. SAE 1541 steel link plates of chains were subjected to cyclical tensile stress due to repeated loading and un-loading conditions. The crack was getting originated from the pitch hole and growth perpendicular to the chain pulling load, due to fatigue mechanism. In general plate holes are manufactured using the conventional process. An additional novel technique called the slip ball burnishing (SBB) method is applied for improving the hole properties. The improvement is made by producing local plastic deformation, improving surface finish and compressive residual stress throughout in the pierced hole. Both the conventional process (CP) and the SBB technique have been evaluated by optical, profile, surface roughness and micro harness tests. Experimental fatigue test validations were done in both chain samples using the Johnson-Goodman method. SBB chains passed 3x106 cycles at the load of 17.61 kN and CP chains passed 3x106 cycles at the load of 13.92 kN. The conclusion was that SBB made a significant improvement of 26.51 per cent of fatigue strength compared to CP.

Dynamic Analysis of Residual Stress Introduced by Laser Peening

2006 ◽  
Vol 524-525 ◽  
pp. 135-140 ◽  
Author(s):  
Koichi Akita ◽  
Masatoshi Kuroda ◽  
Philip J. Withers
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Pressure Pulse ◽  
Peak Pressure ◽  
Single Pulse ◽  
Laser Peening ◽  
Threshold Pressure ◽  
Focusing Effect ◽  
Dynamic Finite Element ◽  
Long Pulse

Residual stress induced by laser single pulse irradiation was analyzed using a dynamic finite element code, ABAQUS/Explicit. The effects of the magnitude and length of a surface pressure pulse having a circular top-hat shape on the final residual stress in Ti-6Al-4V were investigated. A high peak pressure and/or a long pulse duration was effective in generating large compressive residual stress deep beneath the surface. However, large tensile residual stress features occurred near the centre and edge of the laser spot on the surface for high pressure and/or long pulse durations due to a radial focusing effect. Use of shorter pulse durations avoided this. The peak pressure (3GPa) required to induce a surface compressive residual stress across the whole area of the spot was slightly higher than the threshold pressure needed to plastically deform the surface.

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