An Evaluation of Abrasive Waterjet Peening With Elastic Prestress

2009 ◽  
Vol 131 (1) ◽  
Author(s):  
B. Sadasivam ◽  
A. Hizal ◽  
S. Park ◽  
D. Arola
Keyword(s):  
Residual Stress ◽  
Yield Strength ◽  
Surface Texture ◽  
Surface Stress ◽  
Treatment Process ◽  
Abrasive Waterjet ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Stress Zone ◽  
Study Application

Abrasive waterjet peening (AWJP) has been conceived as a new surface treatment process capable of achieving desired changes in surface texture, chemistry, and residual stress simultaneously. In the present investigation, the influence of elastic prestress on the residual stress resulting from AWJP was studied. Treatments were conducted on steel, as well as nickel and titanium alloy targets subjected to an elastic prestress ranging from 0% to 75% of the material’s yield strength. The results showed that a tensile elastic prestress increases the surface residual stress and the depth of the compressive stress zone. The surface residual stress in each metal increased nonuniformly with magnitude of prestress; the maximum surface residual stress was obtained at an applied prestress between 45% and 60% of the substrate yield strength. Overall, the increases in surface stress and depth that were obtained reached 100% and 50%, respectively. There were no changes to the surface texture caused by the prestress. According to results of this study, application of an elastic prestress can serve as an effective method for improving characteristics of the residual stress field in components treated using AWJP.

Abrasive Waterjet Peening With Elastic Prestress: Subsurface Residual Stress Distribution

2007 ◽  
Author(s):  
Balaji Sadasivam ◽  
Alpay Hizal ◽  
Dwayne Arola
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Stress Field ◽  
Yield Strength ◽  
Residual Stresses ◽  
Residual Stress Distribution ◽  
Abrasive Waterjet ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Compressive Residual Stresses

Recent advances in abrasive waterjet (AWJ) technology have resulted in new processes for surface treatment that are capable of introducing compressive residual stresses with simultaneous changes in the surface texture. While the surface residual stress resulting from AWJ peening has been examined, the subsurface residual stress field resulting from this process has not been evaluated. In the present investigation, the subsurface residual stress distribution resulting from AWJ peening of Ti6Al4V and ASTM A228 steel were studied. Treatments were conducted with the targets subjected to an elastic prestress ranging from 0 to 75% of the substrate yield strength. The surface residual stress ranged from 680 to 1487 MPa for Ti6Al4V and 720 to 1554 MPa for ASTM A228 steel; the depth ranged from 265 to 370 μm for Ti6Al4V and 550 to 680 μm for ASTM A228 steel. Results showed that elastic prestress may be used to increase the surface residual stress in AWJ peened components by up to 100%.

Abrasive Waterjet Peening With Elastic Prestress: Effect of Boundary Conditions

2008 ◽  
Author(s):  
Balaji Sadasivam ◽  
Alpay Hizal ◽  
Dwayne Arola
Keyword(s):  
Residual Stress ◽  
Yield Strength ◽  
Boundary Conditions ◽  
Stress Fields ◽  
Abrasive Waterjet ◽  
Surface Residual Stress ◽  
Prosthetic Devices ◽  
Metal Implants ◽  
Removal Technique ◽  
Stored Elastic Energy

Abrasive Waterjet Peening (AWJP) has emerged as a potential surface treatment process for metal implants and prosthetic devices. An elastic tensile prestress has been shown to increase the magnitude and depth of residual stress that can be obtained. In the present investigation, the subsurface residual stress fields resulting from AWJ peening of Ti6Al4V with load control and displacement control elastic prestress were compared. Prestress ranged from 0 to 75% of the material’s yield strength and the subsurface residual stress distribution was quantified using the layer removal technique. Results showed that the surface residual stress was dependent on the boundary conditions for prestress levels less than 60% of the materials yield strength. The magnitude of surface residual stress and the stored elastic energy were up to 50% and 100% larger respectively when load controlled boundary conditions were used. However, the boundary condition did not affect the depth of compressive residual stress.

Finite element analysis of residual stress evolution with multiple impacts on one point in ultrasonic impact treatment process

2016 ◽  
Vol 232 (7) ◽  
pp. 1201-1211 ◽  
Author(s):  
Shengsun Hu ◽  
Chaobo Guo ◽  
Dongpo Wang ◽  
Zhijiang Wang ◽  
Chao Huang
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Treatment Process ◽  
Equivalent Plastic Strain ◽  
Multiple Impacts ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Element Analysis ◽  
Ultrasonic Impact Treatment

The ultrasonic impact treatment process is widely used to improve the fatigue life of the weldments by inducing compressive residual stresses at the sub-surface. The purpose of the article is to conduct the dynamic elastic–plastic finite element analysis of multiple impacts on 5A06 aluminum alloy with different controlled parameters. The numerical model was validated by pin drop test. The changes in penetration depth, maximum compressive residual stress, and surface residual stress were obtained by analyzing the residual stress field and equivalent plastic strain. The effect of impact times, impact velocities, pin shapes, and impact angles on the residual stress was investigated so that the ultrasonic impact treatment parameters could be controlled to obtain expected residual stress distributions.

Finite Element Based Evaluation of Abrasive Waterjet Peening With Elastic Prestress: Effect of Prestress Loading

2012 ◽  
Author(s):  
Balaji Sadasivam ◽  
Dwayne Arola
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Treatment Process ◽  
High Cycle Fatigue ◽  
Potential Surface ◽  
Axial Loading ◽  
Fatigue Loading ◽  
Stress Fields ◽  
Abrasive Waterjet ◽  
Residual Stress Field

Abrasive Waterjet (AWJ) peening has emerged as a potential surface treatment process for components subjected to high–cycle fatigue loading and that require a “rough” surface. Conducting treatments while subjecting the surface to tensile elastic prestress has resulted in an increase in the magnitude and depth of residual stress. Recent finite element based studies have revealed that the residual stress field in AWJ peening is influenced by the boundary conditions and whether the prestress is administered by load or displacement control. However, previous investigations concerned with AWJ peening have been limited to a flexural loading arrangement to achieve tensile prestress of the treated surface. In the present investigation, a finite element based study is conducted to evaluate the effect of prestress loading configurations and a comparison of flexural vs axial loading on the residual stress fields resulting from peening surface treatments. Results show that the prestress loading influences the depth of residual stress and axial prestress results in a greater depth than that achieved with flexure prestress.

Advanced Evaluation Methods of Residual Stress in Bioceramics Wear Surfaces

2010 ◽  
Vol 64 ◽  
pp. 43-48
Author(s):  
Giuseppe Pezzotti
Keyword(s):  
Residual Stress ◽  
Surface Stress ◽  
Electron Probe ◽  
Stress Fields ◽  
Fluorescence Probes ◽  
Surface Residual Stress ◽  
Hip Joints ◽  
Polycrystalline Alumina ◽  
Probe Size ◽  
F Center

Photo- and electro-stimulated probes have been employed for quantitatively evaluating highly graded residual stress fields generated at the surface of alumina hip joints. Optical calibrations revealed large differences in probe size, which strongly affected the detected magnitude of residual stress. A comparison between the responses of Raman and fluorescence probes in polycrystalline alumina showed that the depth of those probes spread to an extent in the order of the tens of microns even with using a confocal probe configuration. On the other hand, the electro-stimulated luminescence emitted by oxygen vacancy sites (F+ center) in the alumina lattice represented a suitable choice for confining to a shallow volume the stress probe. The electron probe enabled confining the measurement depth to the order of the tens of nanometers. Maps of surface residual stress were collected on both main-wear and non-wear zones of an alumina femoral head. A comparison among stress maps taken at exactly the same location, but employing different probes, clarified the averaging probe effects on surface stress magnitude.

Numerical Simulation of Influences of Preheating and Postweld Heat Treatment in Welding

2012 ◽  
Vol 538-541 ◽  
pp. 1518-1521
Author(s):  
Qing Yang ◽  
Shu Jun Xie ◽  
Tian Bao Yu
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Stress Distribution ◽  
Treatment Process ◽  
Postweld Heat Treatment ◽  
Element Model ◽  
Residual Stress Field ◽  
Pipe Welding ◽  
Postweld Heat ◽  
The Finite Element Model

In this paper, to investigative effects of preheating and postweld heat treatment on residual stress field in Q345 steel pipe welding, the finite element model was established. Preheating processes and postweld heat treatment process were simulated respectively. The results show that preheating can homogenize residual stress distribution of the weldment and decrease the residual stress. The heat treatment reduces the residual stress in inner and outer walls by 40% and 60% respectively and the stress distribution is more even and the stress concentration is reduced.

Growth of surface flaws induced by the environment and machining stresses in unalloyed uranium

2005 ◽  
Vol 40 (2) ◽  
pp. 139-150 ◽  
Author(s):  
A Wallwork ◽  
G Burnell ◽  
S Morris ◽  
A Rowe ◽  
I Clarke ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Computer Modelling ◽  
Crack Nucleation ◽  
Initial Assessment ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Near Surface ◽  
Surface Features ◽  
Subsequent Propagation

Computer modelling techniques are used to predict the distribution of residual stresses in a machined uranium surface. The predictions are used to address the ageing of uranium exposed to inert gas based environments in terms of microcrack initiation and subsequent propagation. Metallographic observations of microcracking are used as the basis for the initial assessment of ageing behaviour. It is proposed that the near-surface residual stress field produced by machining influences the occurrence of microcracking. It is also suggested that corrosion-induced surface features act as initiation sites for microcracks, which begin to propagate by an environmentally assisted mechanism when the surface features reach a critical depth within the residual stress field of between 5 and 10 μm. However, the majority of the microcracks appear to arrest at about 150 μm. This behaviour is discussed in terms of the predicted threshold stress intensity for crack nucleation, uranium metallurgy, and the possible effects of crack coalescence on growth.

Mapping of Surface Residual Stress Field by Laser Interferometry Using Stress Relaxation Method

2002 ◽  
Vol 750 ◽  
Author(s):  
Dong-Won Kim ◽  
Nak-Kyu Lee ◽  
Kyung-Hoan Na ◽  
Dongil Kwon
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Speckle Pattern ◽  
Thermal Strain ◽  
Laser Interferometry ◽  
Relaxation Method ◽  
Electronic Speckle Pattern Interferometry ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Au Film

ABSTRACTBased on the identification of the residual stress-free state using electronic speckle pattern interferometry (ESPI), we modeled the relaxed stress in annealing, the thermal strain/stress and the residual stress field in case of both single and film/substrate systems by using the thermo-elastic theory and the relationship between relaxed stresses and displacements. Thus we mapped the surface residual stress fields on the indented bulk Cu and the 0.5μm Au film by ESPI. In indented Cu, the normal and shear residual stress are distributed over -800 MPa to 700 MPa and -600 MPa to 600 MPa respectively around the indented point and in deposited Au film on Si wafer, the tensile residual stress is uniformly distributed on the Au film from 500 MPa to 800 MPa. Also we measured the residual stress by the x-ray diffractometer (XRD) for the verification of above residual stress results by ESPI.

Surface Stress Concentration Analysis of Shot Peened Aluminium Alloys

2010 ◽  
Vol 449 ◽  
pp. 70-76
Author(s):  
J. Solis-Romero ◽  
J. Oseguera-Peña ◽  
J. Verduzco-Martínez ◽  
J. González-Sánchez
Keyword(s):  
Residual Stress ◽  
Stress Concentration ◽  
Surface Stress ◽  
Aluminium Alloys ◽  
Stress Gradient ◽  
Stress Effect ◽  
Surface Residual Stress ◽  
Closure Stress ◽  
Surface Crack Initiation ◽  
Effect Of Surface

Fatigue limit for surface crack initiation on shot peened Aluminium Alloys resulted to be determined by surface residual stress and stress concentration, according to the magnitude of the applied stress. The effect of surface roughness considered as micro-notches (dents) has been analysed by using the Vallellano and Navarro’s formulation. It was also determined that the stress gradient associated to those dents dominates over the closure stress effect.

A Method for Improving Compressive Residual Stress of Small Holes Surface by Water-Jet Cavitation Peening

2009 ◽  
Vol 614 ◽  
pp. 137-142 ◽  
Author(s):  
B. Han ◽  
Dong Ying Ju
Keyword(s):  
Residual Stress ◽  
Surface Layer ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Water Jet ◽  
Surface Residual Stress ◽  
Near Surface ◽  
Stress Zone ◽  
Strengthening Technique ◽  
Small Holes

As a novel surface strengthening technique, Water-jet cavitation peening has been applied to improve the fatigue life by inducing the compressive residual stress in the near surface layer of mechanical components. Compared with conventional shot peening, one advantage of WCP is that the complicated and tiny surface can be peened more easily. In this study, the small holes with various diameters and depths in the SUS304 stainless steel specimens were treated by WCP. In order to estimate its strengthening capability to the small holes, the surface residual stress and the depth distributions in the near surface layer of the small holes were measured by X-ray diffraction method. The experimental results show that WCP can successfully improve the near surface compressive residual stress of small holes. The maximum of surface compressive residual stress of WCP state is up to around –450 MPa. The dept of compressive residual stress zone is up to around 125 μm.

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