Characterization of a Water Peening Process

1999 ◽  
Vol 121 (3) ◽  
pp. 336-340 ◽  
Author(s):  
S. R. Daniewicz ◽  
S. D. Cummings

A traversing water jet was used to impact the surface of 1100 series aluminum specimens in an effort to generate compressive residual stresses on the surface. Stresses induced by the water peening operation were measured using X-ray diffraction, and compressive stress increases as large as 60 percent of the monotonic yield strength resulted. Surface roughness and hardness were also measured. Finite element modeling of a stationary water jet impinging on an elastic-plastic half-space was performed to characterize the water peening process. Surface residual stresses were found to be a result of sub-surface plastic deformations.

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.


2012 ◽  
Vol 723 ◽  
pp. 208-213 ◽  
Author(s):  
Yi Wan ◽  
Chen Li ◽  
Zhan Qiang Liu ◽  
Shu Feng Sun

Residual stresses generated in milling process affect the performance of machined components. Milling residual stresses correlate closely with the cutting parameters. In this paper, the generation and distribution of surface residual stresses in milling of aluminum alloy 7050-T7451 was investigated. The cutting speed changes from 300m/min to 3000m/min. In the experiments, the residual stresses on the surface of specimen are detected by X-ray diffraction technique. The result shows that compressive residual stresses are generated when cutting speed is under 500 m/min. In feed and its orthogonal direction, the effect of cutting speed and feed rate on residual stresses is similar. The formation of the residual stresses can be explained by thermo-mechanical coupling effects.


1994 ◽  
Vol 38 ◽  
pp. 455-461
Author(s):  
R. Lin ◽  
B. Jaensson ◽  
T. M. Holden ◽  
R. B. Rogge ◽  
J. H. Root

Sleeve coldworking (SCW) is a mechanical process used in the aircraft industry to strengthen fastener holes of structural parts. By cold-expanding the holes, compressive residual stresses and a high dislocation density are introduced around the holes, the effect of which is to counteract the initiation and propagation of fatigue cracks and thus increase the fatigue life of the parts. The knowledge of residual stress due to SCW is therefore crucial for assessing the fatigue properties of a treated part. In this study, residual stresses were investigated, by employing neutron and X-ray diffraction methods, in a lug specimen that was sleeve coldworked and fatigued. The specimen had been used for testing the influence of the SCW process on fatigue life and crack propagation behaviour under constant amplitude or variable amplitude cyclic loading.


1996 ◽  
Vol 118 (4) ◽  
pp. 483-489 ◽  
Author(s):  
Y. Ahn ◽  
S. Chandrasekar ◽  
T. N. Farris

Machining produces surface residual stresses which significantly influence the strength and wear resistance of ceramic components. As new methods are developed for machining ceramics, a quick and reliable technique for measurement of residual stresses would be valuable in assessing the viability of these methods from a residual stress perspective. The residual stresses on ground and polished (i.e. machined) surfaces of soda-lime glass, Ni-Zn ferrite, and silicon nitride have been measured using an indentation technique with a Vickers indenter. In this technique, the surface extent of the median/radial cracks produced by the Vickers indenter in machined and in annealed ceramics are measured. These are then combined with a fracture mechanics analysis to estimate the surface residual stresses produced by machining. In order to determine the validity of the indentation technique for estimating machining residual stresses, these stresses were also measured using an X-ray diffraction and a deflection method. The residual stress values determined using the indentation technique in the machined ceramics were found to be reasonably close to those obtained from the X-ray diffraction and deflection methods. Since the indentation technique is relatively simple and easily applied, it offers a promising method for evaluating surface residual stresses in machined ceramics.


2016 ◽  
Vol 9 (3) ◽  
pp. 649-653
Author(s):  
Frank Anthony Cuccia ◽  
James Pineault ◽  
Mohammed Belassel ◽  
Michael Brauss

2014 ◽  
Vol 996 ◽  
pp. 181-186 ◽  
Author(s):  
Eric Wasniewski ◽  
Baptiste Honnart ◽  
Fabien Lefebvre ◽  
Eric Usmial

Laboratory X-ray diffraction is commonly used for surface residual stresses determination. Nevertheless, the in-depth residual stress gradient also needs to be known. Chemical or electro-polishing method is generally used for material removal. However, material removal may seek a new equilibrium and stress field may change in such a way that experimental residual stress values must be corrected. Different methods exist to account for the residual stress relaxation associated with the material removal operation and will be discussed in this paper.


2007 ◽  
Vol 129 (4) ◽  
pp. 609-613 ◽  
Author(s):  
A. Sahaya Grinspan ◽  
R. Gnanamoorthy

A new surface modification process was developed to introduce compressive residual stresses at the surface of components. In this process, instead of oil droplets a high-velocity cavitation jet (cloud of oil bubbles) impinges on the surface of the component to be peened. The impact pressure generated during implosion of cavitation bubbles causes severe plastic deformation at the surface. Consequently, beneficial compressive stresses are developed at the surface. In order to find the potential of this process, aluminum alloy AA6063-T6 specimens were peened at a constant cavitation number with various nozzle-traveling velocities. Residual stress induced by oil jet cavitation peening was measured using X-ray diffraction. Oil cavitation jet peening results in a smooth and hard surface. The developed compressive residual stresses at the peened surface are about 52%, 42%, and 35% of yield strength in samples for peened at nozzle traveling velocities of 0.05mm∕s, 0.10mm∕s, and 0.15mm∕s, respectively.


1989 ◽  
Vol 149 ◽  
Author(s):  
P. D. Persans ◽  
A. F. Ruppert ◽  
B. Abeles ◽  
G. Hughes ◽  
K. S. Liang

ABSTRACTWe discuss high-resolution x-ray diffraction measurements on a-Si:H/a-Ge:H periodic amorphous multilayers. Analysis of the data using the dynamical theory yields information on layer thicknesses and densities, interface and surface roughness, and structural defects such as layer thickness fluctuations.


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