Characterization of Plastic Deformation Induced by Microscale Laser Shock Peening

2004 ◽  
Vol 71 (5) ◽  
pp. 713-723 ◽  
Author(s):  
Hongqiang Chen ◽  
Jeffrey W. Kysar ◽  
Y. Lawrence Yao
Keyword(s):  
Plastic Deformation ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Electron Backscatter Diffraction ◽  
Fem Analysis ◽  
Copper Sample ◽  
Laser Shock Peening ◽  
Lattice Rotation ◽  
Laser Shock ◽  
Shock Peening

Electron backscatter diffraction (EBSD) is used to investigate crystal lattice rotation caused by plastic deformation during high-strain rate laser shock peening in single crystal aluminum and copper sample on 110¯ and (001) surfaces. New experimental methodologies are employed which enable measurement of the in-plane lattice rotation under approximate plane-strain conditions. Crystal lattice rotation on and below the microscale laser shock peened sample surface was measured and compared with the simulation result obtained from FEM analysis, which account for single crystal plasticity. The lattice rotation measurements directly complement measurements of residual strain/stress with X-ray micro-diffraction using synchrotron light source and it also gives an indication of the extent of the plastic deformation induced by the microscale laser shock peening.

Experimental Characterization and Simulation of Three Dimensional Plastic Deformation Induced by Microscale Laser Shock Peening

2004 ◽  
Author(s):  
Hongqiang Chen ◽  
Jeffrey W. Kysar ◽  
Y. Lawrence Yao ◽  
Youneng Wang
Keyword(s):  
Plastic Deformation ◽  
Single Crystal ◽  
Three Dimensional ◽  
Finite Size ◽  
Fem Analysis ◽  
Laser Shock Peening ◽  
Lattice Rotation ◽  
Finite Size Effect ◽  
Laser Shock ◽  
Shock Peening

Different experimental techniques and 3D FEM simulations are employed to characterize and analyze the three dimensional plastic deformation and residual strain/stress distribution for single crystal Aluminum under microscale laser shock peening assuming finite geometry. Single pulse shock peening at individual locations was studied. X-ray micro-diffraction techniques based on a synchrotron light source affords micron scale spatial resolution and is used to measure the residual stress spatial distribution along different crystalline directions on the shocked surface. Crystal lattice rotation due to plastic deformation is also measured with electron backscatter diffraction (EBSD). The result is experimentally quantified and compared with the simulation result obtained from FEM analysis. The influence of the finite size effect, crystalline orientation are investigated using single crystal plasticity in FEM analysis. The result of the 3D simulations of a single shock peened indentation are compared with the FEM results for a shocked line under 2D plain strain deformation assumption. The prediction of overall character of the deformation and lattice rotation fields in three dimensions will lay the ground work for practical application of μLSP.

Dynamic Material Response of Aluminum Single Crystal Under Microscale Laser Shock Peening

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Sinisa Vukelic ◽  
Youneng Wang ◽  
Jeffrey W. Kysar ◽  
Y. Lawrence Yao
Keyword(s):  
Residual Stresses ◽  
Single Crystals ◽  
Electron Backscatter Diffraction ◽  
Target Material ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Laser Target ◽  
Aluminum Single Crystal ◽  
Anisotropic Mechanical Properties ◽  
Shock Peening

The process of laser shock peening induces compressive residual stresses in a material to improve material fatigue life. For micron sized laser beams, the size of the laser-target interaction zone is of the same order of magnitude as the target material grains, and thus the target material must be considered as being anisotropic and inhomogeneous. Single crystals are chosen to study the effects of the anisotropic mechanical properties. It is also of interest to investigate the response of symmetric and asymmetric slip systems with respect to the shocked surface. In the present study, numerical and experimental aspects of laser shock peening on two different crystal surfaces (110) and (11¯4) of aluminum single crystals are studied. Lattice rotations on the top surface and cross section are measured using electron backscatter diffraction, while residual stress is characterized using X-ray microdiffraction. A numerical model has been developed that takes into account anisotropy as well as inertial terms to predict the size and nature of the deformation and residual stresses. Obtained results were compared with the experimental finding for validation purpose.

A Study of the Microstructure and Hardness of Ti-5Al-2Sn-2Zr-4Mo-4Cr by Laser Shock Peening

2011 ◽  
Vol 84-85 ◽  
pp. 471-475 ◽  
Author(s):  
Wei Feng He ◽  
Yu Qin Li ◽  
Xiang Fan Nie ◽  
Rui Jun Liu ◽  
Qi Peng Li
Keyword(s):  
Shock Wave ◽  
Plastic Deformation ◽  
Titanium Alloy ◽  
High Strain ◽  
The Other ◽  
Laser Shock Peening ◽  
Microscopic Structure ◽  
Laser Shock ◽  
High Strain Rate Deformation ◽  
Shock Peening

In this paper, the microstructure and hardness of Ti-5Al-2Sn-2Zr-4Mo-4Cr titanium alloy with and without laser shock peening (LSP) were examined and compared. The titanium alloy samples were laser shock peened with different layers at the same power density. The microscopic structure after LSP are tested and analyzed by SEM and TEM. The results indicated that LSP changed the microstructure evidently. After 3 layers laser shock peening, there are nanocrystallization in the LSP zone. The shock wave provided high strain rate deformation and generated high-density dislocations in the material. Multiple severe plastic deformation caused by 3 to 5 LSP layers helped to rearrange the resultant dislocation, to form dislocation networks, leading to the formation of nanocrystallites. On the other hand, the microhardness across the polished surfaces of the titanium materials with and without LSP was measured. It is obvious that the laser shock peening improved the microhardness of the Ti-5Al-2Sn-2Zr-4Mo-4Cr for about 16% at the surface, and the affected depth is about 300 microns from the surface.

scholarly journals A Novel Micro-Scale Plastic Deformation Feature on a Bulk Metallic Glass Surface under Laser Shock Peening

2013 ◽  
Vol 30 (3) ◽  
pp. 036201 ◽  
Author(s):  
Yan-Peng Wei ◽  
Bing-Chen Wei ◽  
Xi Wang ◽  
Guang-Yue Xu ◽  
Lei Li ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Glass Surface ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Micro Scale ◽  
Deformation Feature ◽  
Shock Peening

Waterjet Peening At 600MPa: A First Investigation

2005 ◽  
Author(s):  
M. Hashsish ◽  
A. Chillman ◽  
M. Ramulu
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Treatment Process ◽  
Laser Shock Peening ◽  
Material Surface ◽  
Laser Shock ◽  
Ultra High Pressure ◽  
Shock Peening ◽  
Droplet Impacts ◽  
Compressive Residual Stresses

An experimental study was conducted to explore the high-pressure waterjet (WJ) peening at 600MPa on the surface integrity and texture of metals. The concept of larger droplet size and multiple droplet impacts resulting from an ultra high-pressure waterjet (UHPWJ) was used to explore and develop the peening process. A combination of microstructure analysis, microhardness measurements, and profilometry were used in determining the depth of plastic deformation and surface texture that result from the surface treatment process. It was found that waterjet peening at 600MPa induces plastic deformation to greater depths in the sub-surface layer of metals than laser shock peening. The degree of plastic deformation and the state of material surface were found to be strongly dependent on the peening conditions and desired surface roughness. Based on these first investigation results, water peening at 600MPa may serve as a new method for introducing compressive residual stresses in engineering components.

Spatially Resolved Characterization of Residual Stress Induced by Micro Scale Laser Shock Peening

2004 ◽  
Vol 126 (2) ◽  
pp. 226-236 ◽  
Author(s):  
Hongqiang Chen ◽  
Y. Lawrence Yao ◽  
Jeffrey W. Kysar
Keyword(s):  
Residual Stress ◽  
Cell Structure ◽  
Fem Analysis ◽  
Dislocation Cell ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
X Ray ◽  
Micro Scale ◽  
Spatially Resolved ◽  
Shock Peening

Single crystal aluminum and copper of (001) and (110) orientation were shock peened using laser beam of 12 micron diameter and observed with X-ray micro-diffraction techniques based on a synchrotron light source. The X-ray micro-diffraction affords micron level resolution as compared with conventional X-ray diffraction which has only mm level resolution. The asymmetric and broadened diffraction profiles registered at each location were analyzed by sub-profiling and explained in terms of the heterogeneous dislocation cell structure. For the first time, the spatial distribution of residual stress induced in micro-scale laser shock peening was experimentally quantified and compared with the simulation result obtained from FEM analysis. Difference in material response and microstructure evolution under shock peening were explained in terms of material property difference in stack fault energy and its relationship with cross slip under plastic deformation. Difference in response caused by different orientations (110 and 001) and active slip systems was also investigated.

Study of anisotropic character induced by microscale laser shock peening on a single crystal aluminum

2007 ◽  
Vol 101 (2) ◽  
pp. 024904 ◽  
Author(s):  
Hongqiang Chen ◽  
Youneng Wang ◽  
Jeffrey W. Kysar ◽  
Y. Lawrence Yao
Keyword(s):  
Single Crystal ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Anisotropic Character ◽  
Shock Peening
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