scholarly journals Parametric Study of Fixtured Vibropeening

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 910 ◽  
Author(s):  
Chan ◽  
Ahluwalia ◽  
Gopinath

Vibropeening is a surface treatment process, which combines the peening effect of introducing residual stress with the polishing effect of reducing surface roughness in one single process step. Vibropeening equipment induces vibrations into the media to impart residual compressive stresses in sub-surface layers, as well as polishing on the surface of the work piece. In addition to process parameters, such as vibration frequency, amplitude, and media mass, which are well known in literature, this paper will focus on the study of two additional parameters: immersion depth and process time. It was found that the lower-middle section of the vibratory trough produced the highest Almen deflection. Different continuous treatment times were also studied to explore the maximum introducible residual compressive stress state, and it was concluded that an optimal time range is required to achieve the best residual stress profile. The study demonstrates that different process parameters can influence the effectiveness of the vibropeening process, and that these can be potentially optimized for higher treatment capability.

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 655 ◽  
Author(s):  
Zina Kallien ◽  
Sören Keller ◽  
Volker Ventzke ◽  
Nikolai Kashaev ◽  
Benjamin Klusemann

Laser Peening (LP) is a surface modification technology that can induce high residual stresses in a metallic material. The relation between LP process parameters, in particular laser sequences, as well as pulse parameters and the resulting residual stress state was investigated in this study. The residual stress measurements, performed with the hole drilling technique, showed a non-equibiaxial stress profile in laser peened AA2024-T3 samples with a clad layer for certain parameter combinations. Shot overlap and applied energy density were found to be crucial parameters for the characteristic of the observed non-equibiaxial residual stress profile. Furthermore, the investigation showed the importance of the advancing direction, as the advancing direction influences the direction of the higher compressive residual stress component. The direction of higher residual stresses was parallel or orthogonal to the rolling direction of the material. The effect was correlated to the microstructural observation obtained via electron backscattered diffraction. Additionally, for peening with two sequences of different advancing directions, the study showed that the order of applied advancing directions was important for the non-equibiaxiality of the resulting residual stress profile.


Author(s):  
Ok Chan Jeong ◽  
Sang Sik Yang

The paper represents the effects of the drive-in process parameters on the residual stress profile of the p+ silicon film quantitatively. Since the residual stress profile is not uniform along the direction normal to the surface, the residual stress is assumed to be a polynomial function of the depth. All of the coefficients of the polynomial are determined from the deflections of cantilevers and the displacement of a rotating beam structure, which are measured with a surface profiler meter and a microscope. As the drive-in temperature or the drive-in time increases, the boron concentration decreases and the magnitude of the average residual tensile stress decreases. Also, near the surface of the p+ film the residual tensile stress is transformed into the residual compressive stress and its magnitude increases. The correlation coefficients between the residual stress profiles and the simulated boron concentration are calculated. As the drive-in time and temperature increase, all correlation coefficients become close to 1, and the boron concentration profiles after the drive-in process are similar to the stress profiles. Also, the lattice contractions of test wafers are measured by HRXRD (High Resolution X-Ray Diffractometry).


Author(s):  
Abdalla Elbella ◽  
Fawaz Fadul ◽  
Sri Harsha Uddanda ◽  
Nagender Reddy Kasarla

The shot peening process is known for the surface treatment of metallic components. The process is used to enhance surface strength and extend component fatigue life by introducing a compressive residual stress pattern in the surface layers of the component. Numerical simulation of the shot peening process is a tool that has been recently used to help control the process. The simulation helps in investigating the effects of the process parameters with an aim of attaining the optimum residual stress profile and maximum process gain. In this paper, elasto-plastic finite element simulation is used to perform this investigative analysis. The process parameters that are varied in this analysis are: the shot diameter, shot velocity, incidence angle and target material. The analysis is to be carried for three different materials, namely, steel, aluminum and titanium. An Explicit commercial finite element code (ABAQUS) is used to simulate the impact phenomenon. The results of the analysis are sets of varying plots of residual stress through the depth of the targets.


Author(s):  
Abdalla Elbella ◽  
Vishal Rami ◽  
Jyothi Hogirala

Shot peening process is largely used for surface treatment of metallic components with the aim of increasing surface toughness and extending fatigue life. The fatigue strength of the component can be improved by inducing compressive residual stress in the surface and subsurface layers by the shot peening process. Numerical simulation of the shot peening process is an important tool that is used to aid in understanding the effects of the process parameters on intended goal of attaining the optimum residual stress profile and maximum process gain. In this paper an elasto-plastic finite element model is used for the shot peening process. The process parameters that are varied in this analysis are: the shot diameter, shot speed, number of shots at a given time (coverage) and target material. The analysis is carried out for two different materials, namely, steel and aluminum. An Explicit finite element code (ABAQUS) is used to perform this task. These parameters have different effects on the resulting residual profile and the results of the study showed that by adjusting these parameters, the most effective residual stress profile could be obtained.


2018 ◽  
Vol 213 ◽  
pp. 623-629 ◽  
Author(s):  
F. Valiorgue ◽  
V. Zmelty ◽  
M. Dumas ◽  
V. Chomienne ◽  
C. Verdu ◽  
...  

2000 ◽  
Vol 123 (2) ◽  
pp. 162-168 ◽  
Author(s):  
M. B. Prime

A powerful new method for residual stress measurement is presented. A part is cut in two, and the contour, or profile, of the resulting new surface is measured to determine the displacements caused by release of the residual stresses. Analytically, for example using a finite element model, the opposite of the measured contour is applied to the surface as a displacement boundary condition. By Bueckner’s superposition principle, this calculation gives the original residual stresses normal to the plane of the cut. This “contour method” is more powerful than other relaxation methods because it can determine an arbitrary cross-sectional area map of residual stress, yet more simple because the stresses can be determined directly from the data without a tedious inversion technique. The new method is verified with a numerical simulation, then experimentally validated on a steel beam with a known residual stress profile.


Author(s):  
Sai Kosaraju ◽  
Xin Zhao

Abstract A two-dimensional finite element model is developed to simulate the interaction between metal samples and laser-induced shock waves. Multiple laser impacts are applied at each location to increase plastically affected depth and compressive stress. The in-depth and surface residual stress profiles are analyzed at various repetition rates and spot sizes. It is found that the residual stress is not sensitive to repetition rate until it reaches a very high level. At extremely high repetition rate (100 MHz), the delay between two shock waves is even shorter than their duration, and there will be shock wave superposition. It is revealed that the interaction of metal with shock wave is significantly different, leading to a different residual stress profile. Stronger residual stress with deeper distribution will be obtained comparing with lower repetition rate cases. The effect of repetition rate at different spot sizes is also studied. It is found that with larger laser spot, the peak compressive residual stress decreases but the distribution is deeper at extremely high repetition rates.


Author(s):  
David Curtis ◽  
Holger Krain ◽  
Andrew Winder ◽  
Donka Novovic

The grinding process is often maligned by grinding burn; which refers to many unwanted effects, including residual stress formation. This paper presents an overview of the role of grinding wheel technologies in the surface response and residual stress formation of thin section Inconel 718. Using production standard equipment, conventional abrasive vitrified, and super abrasive electroplated wheel technologies were evaluated in initial comparative trials. Results revealed the dominant residual stress profiles, which manifested as measurable distortion and the thermo-mechanical impact of grinding, such as softening. Following this, a parametric study was carried out using cubic boron nitride super abrasive electroplated wheels to investigate the interaction of grinding parameters on the generated output. It was shown that at increased grinding aggressions, tensile stress regimes increased resulting in increased distortion magnitudes. The study highlights the importance of assessing residual stress formation when manipulating both wheel technologies and grinding parameters. It is envisaged that with additional assessment, a route to an engineered residual stress profile might be achieved.


Sign in / Sign up

Export Citation Format

Share Document