Strengthening effect of laser shock: convex model with and without reflection

Based on the FEM code ABAQUS and MSC.Fatigue, the process of LSP before hole-drilling was adopted to study the residual stress field of aluminum alloy7050T7451 with Fastener Holes after Laser shock processing (LSP), and the fatigue life of the specimens by LSP was analyzed in this paper. The results indicate that multiple laser shock processing can improve the residual compressive stress and fatigue life to a certain degree, and with the increasing number of shot, the strengthening effect gradually decreases. The ratio of the fatigue life of specimens treated by LSP to the fatigue life of untreated specimens is gradually decreased as the mean stress σm increases, and when the σm is 67.3MPa, the fatigue life of specimens treated by LSP advances 719%, compared with that of untreated specimens.

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Strengthening effect of laser shock peening on 7075-T6 aviation aluminum alloy

Advances in Mechanical Engineering ◽

10.1177/1687814020952177 ◽

2020 ◽

Vol 12 (8) ◽

pp. 168781402095217

Author(s):

Junhao Zhang ◽

Xiuquan Cheng ◽

Qinxiang Xia ◽

Chang Yan

Keyword(s):

Residual Stress ◽

Aluminum Alloy ◽

Shot Peening ◽

Strain Distribution ◽

Equivalent Strain ◽

Laser Shock Peening ◽

Strengthening Effect ◽

Laser Shock ◽

Shock Peening ◽

Overlap Ratio

The strengthening effect and uniformity of residual stress and strain of 7075-T6 aviation aluminum after laser shock peening were investigated. The finite element simulation model of laser shot peening on 7075-T6 aviation aluminum alloy was established and verified. On this basis and combined with experiment, the microstructure, residual stress distribution and equivalent strain distribution of 7075-T6 aviation aluminum alloy after laser shock peening were studied. An index U for evaluating the strain uniformity in the peened area was proposed based on the statistical processing of the equivalent strain distribution in the peened area. The results show that the average grain size on the peened surface of the specimen was refined to 20–30 μm after LSP, and a residual compressive stress layer with thickness of about 0.5 mm was induced on the surface. Grain refinement and residual compressive stress can promote the strength and fatigue properties of 7075-T6 aviation aluminum alloy. The minimum value of U is obtained in the 6 × 6 spot array (the corresponding overlap ratio is 58%), which suggest that the most uniform deformation peened area can be obtained by using 58% overlap ratio in the laser shot peening process, which can avoid stress concentration and improve fatigue life.

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Strengthening Effect of Laser Shock: Concave Model with and without Reflection

Surface Topography Metrology and Properties ◽

10.1088/2051-672x/abf9f6 ◽

2021 ◽

Author(s):

Liangchen Ge ◽

Haotian Chen ◽

Zongjun Tian ◽

Boyuan Xu ◽

Guoran Hua ◽

...

Keyword(s):

Strengthening Effect ◽

Laser Shock

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Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071363 ◽

1973 ◽

Vol 31 ◽

pp. 184-185

Author(s):

M.S. Grewal ◽

S.A. Sastri ◽

N.J. Grant

Keyword(s):

High Temperature ◽

Nickel Alloys ◽

Thermomechanical Processing ◽

Cold Work ◽

High Temperature Strength ◽

Strengthening Effect ◽

Mechanical Processing ◽

Uniform Dispersion ◽

Oxide Particles ◽

Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

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Effect of Improved ThO2 Particle Dispersion in Nickel on High-Temperature Strength

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069211 ◽

1970 ◽

Vol 28 ◽

pp. 444-445

Author(s):

E. R. Kimmel ◽

H. L. Anthony ◽

W. Scheithauer

Keyword(s):

High Temperature ◽

Metal Matrix ◽

Oxide Particle ◽

Oxide Phase ◽

Dislocation Motion ◽

Particle Dispersion ◽

High Temperature Strength ◽

Strengthening Effect ◽

Oxide Particles ◽

The Stability

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.

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Liquid spall in laser shock-loaded Tin melted on compression or on release

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2006134133 ◽

2006 ◽

Vol 134 ◽

pp. 869-875 ◽

Cited By ~ 2

Author(s):

T. de Rességuier ◽

L. Signor ◽

A. Dragon ◽

M. Boustie ◽

G. Roy ◽

...

Keyword(s):

Laser Shock

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ODS EUROFER Steel Strengthened by Y-(Ce, Hf, La, Sc, and Zr) Complex Oxides

Metals ◽

10.3390/met9111148 ◽

2019 ◽

Vol 9 (11) ◽

pp. 1148 ◽

Cited By ~ 2

Author(s):

Roman Husák ◽

Hynek Hadraba ◽

Zdeněk Chlup ◽

Milan Heczko ◽

Tomáš Kruml ◽

...

Keyword(s):

Grain Size ◽

Yield Strength ◽

Complex Oxides ◽

Oxide Dispersion Strengthened ◽

Interparticle Spacing ◽

Oxide Dispersion ◽

Strengthening Effect ◽

Dispersion Strengthening ◽

Doping Element ◽

Average Grain Size

Oxide dispersion-strengthened (ODS) materials contain homogeneous dispersions of temperature-stable nano-oxides serving as obstacles for dislocations and further pinning of grain boundaries. The strategy for dispersion strengthening based on complex oxides (Y-Hf, -Zr, -Ce, -La) was developed in order to refine oxide dispersion to enhance the dispersion strengthening effect. In this work, the strengthening of EUROFER steel by complex oxides based on Y and elements of the IIIB group (lanthanum, scandium) and IVB group (cerium, hafnium, zirconium) was explored. Interparticle spacing as a dispersoid characteristic appeared to be an important factor in controlling the dispersion strengthening contribution to the yield strength of ODS EUROFER steels. The dispersoid size and average grain size of ODS EUROFER steel were altered in the ranges of 5–13 nm and 0.6–1.7 µm, respectively. Using this strategy, the yield strength of the prepared alloys varied between 550 MPa and 950 MPa depending on the doping element.

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