Micro-bending and patterning via high energy pulse laser peening

2014 ◽  
Author(s):  
Chelsey Nicole Pence
Keyword(s):  
Pulse Laser ◽  
High Energy ◽  
Laser Peening ◽  
Energy Pulse

Surface Micropatterning of Pure Titanium for Biomedical Applications Via High Energy Pulse Laser Peening

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Ninggang Shen ◽  
Hongtao Ding ◽  
Robert Bowers ◽  
Yin Yu ◽  
Chelsey N. Pence ◽  
...  
Keyword(s):  
Shock Wave ◽  
Mechanical Strength ◽  
Pulse Laser ◽  
Biomedical Applications ◽  
Pure Titanium ◽  
Strong Shock ◽  
High Energy ◽  
Laser Peening ◽  
Biomedical Implant ◽  
Energy Pulse

Pure titanium is an ideal material for biomedical implant applications for its superior biocompatibility, but it lacks of the mechanical strength required in these applications compared with titanium alloys. This research is concerned with an innovative laser peening-based material process to improve the mechanical strength and cell attachment property of pure titanium in biomedical applications. Evidence has shown that engineered surface with unsmooth topologies will contribute to the osteoblast differentiation in human mesenchymal pre-osteoblastic cells, which is helpful to avoid long-term peri-abutment inflammation issues for the dental implant therapy with transcutaneous devices. However, surface quality is difficult to control or mechanical strength is not enhanced using conventional approaches. In this paper, a novel high energy pulse laser peening (HEPLP) process is proposed to both improve the mechanical strength and introduce a micropattern into the biomedical implant material of a commercially pure Titanium (cpTi). The strong shock wave generated by HEPLP presses a stainless steel grid, used as a stamp, on cpTi foils to imprint a micropattern. To understand the basic science during the process, the HEPLP induced shock wave pressure profile and history are modeled by a multiphysics hydrodynamic numerical analysis. The micropatterns and strength enhancement are then simulated using a dislocation density-based finite element (FE) framework. Finally, cell culture tests are conducted to investigate the biomedical performance of the patterned surface.

Surface Micro-Scale Patterning for Biomedical Implant Material of Pure Titanium via High Energy Pulse Laser Peening

2014 ◽  
Author(s):  
Ninggang Shen ◽  
Chelsey N. Pence ◽  
Robert Bowers ◽  
Yin Yu ◽  
Hongtao Ding ◽  
...  
Keyword(s):  
Shock Wave ◽  
Dental Implant ◽  
Pulse Laser ◽  
Pure Titanium ◽  
Strong Shock ◽  
High Energy ◽  
Laser Peening ◽  
Implant Surface ◽  
Implant Material ◽  
Energy Pulse

Pure titanium (commercial pure cpTi) is an ideal dental implant material without the leeching of toxic alloy elements. Evidence has shown that unsmooth implant surface topologies may contribute to the osteoblast differentiation in human mesenchymal pre-osteoblastic cells, which is helpful to avoid long-term peri-abutment inflammation issues for the dental implant therapy with transcutaneous devices. Studies have been conducted on the grit blasted, acid etched, or uni-directional grooved Ti surface. However, for these existing approaches, the surface quality is difficult to control or may even damage the implant. A novel idea has been studied in which more complex two-dimensional (2D) patterns can be imprinted into the dental implant material of cpTi by high energy pulse laser peening (HEPLP). The strong shock wave generated by HEPLP press a stainless steel grid, used as a stamp, on Ti foils to imprint a 2D pattern. In this study, the multiple grid patterns and grid sizes were applied to test the cell’s favor. The HEPLP induced shock wave pressure profile and history were simulated by a 2D multi-physics hydrodynamic numerical analysis for a better understanding of this technique. Then, the cell culture tests were conducted with the patterned surface to investigate the contribution of these 2D patterns, with the control tests of the other existing implant surface topography forming approaches.

scholarly journals Dissipative soliton resonance as a guideline for high-energy pulse laser oscillators

2010 ◽  
Vol 27 (11) ◽  
pp. 2336 ◽  
Author(s):  
Philippe Grelu ◽  
Wonkeun Chang ◽  
Adrian Ankiewicz ◽  
Jose M. Soto-Crespo ◽  
Nail Akhmediev
Keyword(s):  
Pulse Laser ◽  
High Energy ◽  
Dissipative Soliton ◽  
Soliton Resonance ◽  
Laser Oscillators ◽  
Energy Pulse

Microstructure and Property of Fe-Based Alloy Modified Layer on 304 Stainless Steel by High-Energy Pulse Laser-Like Cladding (HPLC)

2016 ◽  
Vol 879 ◽  
pp. 2255-2260 ◽  
Author(s):  
C.H. Zhang ◽  
Y.F. Jia ◽  
M. Guan ◽  
C.L. Wu ◽  
J.Z. Tan ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Pulse Laser ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
High Energy ◽  
Wear Testing ◽  
304 Stainless Steel ◽  
Energy Pulse ◽  
Modified Layer ◽  
Cavitation Erosion Resistance

Fe-based alloy modified layers were prepared on 304 stainless steels by high-energy pulse laser-like cold welding cladding technique. The microstructure, composition and phase constituents of the cladding layers were analyzed using SEM, EDS and XRD, respectively. The microhardness, friction-wear and cavitation erosion resistance were also investigated using microhardness tester, pin-on-disk wear-testing machine and ultrasonic vibrator. Experimental results showed that Fe-based alloy modified layer was mainly composed of α-Fe matrix phase and skeleton-like Cr23C6, Cr7C3 carbide reinforced phase, which was dispersively distributed into α-Fe matrix. The microhardness and friction coefficients of Fe-based alloy modified layer were 600HV and 0.4, respectively, indicating an improved wear resistance. The weight loss rate and average erosion depth of the modified layer was 1/5 and 1/10 that of 304 stainless steel in 3.5% NaCl solution after 5-h cavitation erosion test, respectively. The erosion crater depth of the modified layer was uniform, indicating that the cavitation erosion resistance of the modified layer was much better than that of the 304 stainless steel.

scholarly journals Adaptive pulse compression for transform-limited 15-fs high-energy pulse generation

2000 ◽  
Vol 25 (8) ◽  
pp. 587 ◽  
Author(s):  
E. Zeek ◽  
R. Bartels ◽  
M. M. Murnane ◽  
H. C. Kapteyn ◽  
S. Backus ◽  
...  
Keyword(s):  
Pulse Compression ◽  
High Energy ◽  
Pulse Generation ◽  
Energy Pulse

Lifetime Enhancement of Propulsion Shafts Against Corrosion-Fatigue by Laser Peening

2018 ◽  
Author(s):  
Lloyd A. Hackel ◽  
Jon E. Rankin
Keyword(s):  
Corrosion Fatigue ◽  
Fatigue Testing ◽  
Salt Water ◽  
Fatigue Cracks ◽  
Water Immersion ◽  
High Energy ◽  
General Corrosion ◽  
Laser Peening ◽  
Corrosion Pits ◽  
Deep Pits

This paper reports substantially enhanced fatigue and corrosion-fatigue lifetimes of propulsion shaft materials, 23284A steel and 23284A steel with In625 weld overlay cladding, as a result of shot or laser peening. Glass reinforced plastic (GRP) coatings and Inconel claddings are used to protect shafts against general corrosion and corrosion pitting. However salt water leakage penetrating under a GRP can actually enhance pitting leading to crack initiation and growth. Fatigue coupons, untreated and with shot or laser peening were tested, including with simultaneous salt water immersion. Controlled corrosion of the surfaces was simulated with electric discharge machining (EDM) of deep pits enabling evaluation of fatigue and corrosion-fatigue lifetimes. Results specifically show high energy laser peening (HELP) to be a superior solution, improving corrosion-fatigue resistance of shaft and cladding metal, reducing the potential for corrosion pits to initiate fatigue cracks and dramatically slowing crack growth rates. At a heavy loading of 110% of the 23284A steel yield stress and with 0.020 inch deep pits, laser peening increased fatigue life of the steel by 1370% and by 350% in the corrosion-fatigue testing.

scholarly journals Photoacoustic Energy Sensor for Nanosecond Optical Pulse Measurement

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3879 ◽  
Author(s):  
Pil Sang ◽  
Junseok Heo ◽  
Hui Park ◽  
Hyoung Baac
Keyword(s):  
High Energy ◽  
Hybrid Structure ◽  
Ultrasonic Pulse ◽  
Acoustic Frequency ◽  
Pulse Measurement ◽  
Optical Energy ◽  
Energy Meter ◽  
Energy Sensor ◽  
Energy Pulse ◽  
Spectral Ranges

We demonstrate a photoacoustic sensor capable of measuring high-energy nanosecond optical pulses in terms of temporal width and energy fluence per pulse. This was achieved by using a hybrid combination of a carbon nanotube-polydimethylsiloxane (CNT-PDMS)-based photoacoustic transmitter (i.e., light-to-sound converter) and a piezoelectric receiver (i.e., sound detector). In this photoacoustic energy sensor (PES), input pulsed optical energy is heavily absorbed by the CNT-PDMS composite film and then efficiently converted into an ultrasonic output. The output ultrasonic pulse is then measured and analyzed to retrieve the input optical characteristics. We quantitatively compared the PES performance with that of a commercial thermal energy meter. Due to the efficient energy transduction and sensing mechanism of the hybrid structure, the minimum-measurable pulsed optical energy was significantly lowered, ~157 nJ/cm2, corresponding to 1/760 of the reference pyroelectric detector. Moreover, despite the limited acoustic frequency bandwidth of the piezoelectric receiver, laser pulse widths over a range of 6–130 ns could be measured with a linear relationship to the ultrasound pulse width of 22–153 ns. As CNT has a wide electromagnetic absorption spectrum, the proposed pulsed sensor system can be extensively applied to high-energy pulse measurement over visible through terahertz spectral ranges.

Highly-efficient, high-energy pulse-burst Yb-doped fiber laser with transform limited linewidth

2014 ◽  
Author(s):  
Doruk Engin ◽  
Ibraheem Darab ◽  
John Burton ◽  
Jean-Luc Fouron ◽  
Frank Kimpel ◽  
...  
Keyword(s):  
Fiber Laser ◽  
High Energy ◽  
Pulse Burst ◽  
Highly Efficient ◽  
Energy Pulse
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