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.

Electron microscopy study of shock synthesis of silicides

1993 ◽  
Vol 51 ◽  
pp. 1162-1163
Author(s):  
Kenneth S. Vecchio
Keyword(s):  
Shock Wave ◽  
Plastic Deformation ◽  
Close Contact ◽  
Microscopy Study ◽  
High Energy ◽  
Electron Microscopy Study ◽  
Powder Materials ◽  
Porous Powder ◽  
Wave Effects ◽  
Wave Passage

Shock-induced reactions (or shock synthesis) have been studied since the 1960’s but are still poorly understood, partly due to the fact that the reaction kinetics are very fast making experimental analysis of the reaction difficult. Shock synthesis is closely related to combustion synthesis, and occurs in the same systems that undergo exothermic gasless combustion reactions. The thermite reaction (Fe2O3 + 2Al -> 2Fe + Al2O3) is prototypical of this class of reactions. The effects of shock-wave passage through porous (powder) materials are complex, because intense and non-uniform plastic deformation is coupled with the shock-wave effects. Thus, the particle interiors experience primarily the effects of shock waves, while the surfaces undergo intense plastic deformation which can often result in interfacial melting. Shock synthesis of compounds from powders is triggered by the extraordinarily high energy deposition rate at the surfaces of the powders, forcing them in close contact, activating them by introducing defects, and heating them close to or even above their melting temperatures.

The determination of arc temperatures from shock velocities

1957 ◽  
Vol 240 (1220) ◽  
pp. 54-66 ◽  
Keyword(s):  
Shock Wave ◽  
Strong Shock ◽  
Weak Shock ◽  
Wave Theory ◽  
New Method ◽  
Shock Propagation ◽  
Plane Shock ◽  
Gas Temperature ◽  
Specific Heats ◽  
Arc Discharges

The measurement of the high gas temperatures associated with arc discharges requires special techniques. One such method, developed by Suits (1935), depends on the measure­ment of the velocity of a sound wave passing through an arc column, although in fact Suits measured the velocity of a very weak shock wave. The new method described in the present paper is one in which temperatures are determined from the measurement of the velocity of a relatively strong shock wave propagated through an arc. The new method has the merit of consistently producing accurately measurable records and of increasing the accuracy of the temperature determination. The shock velocities are measured by means of a rotating mirror camera. Within the arc, the shock propagation is observable by virtue of the increased arc brightness produced by the shock. In the non-luminous regions surrounding the arc, the shock propagation is displayed by means of a Schlieren system. The interpretation of the measurements depends upon a one-dimensional analysis given in this paper which is similar to that of Chisnell (1955) and which describes the interaction of a plane shock with a con­tinuously varying temperature distribution. In our analysis account is taken also of the continuous variation in specific heats and molecular weight which are of importance under high gas temperature conditions. In practice plane wave theory cannot adequately describe the shock propagation, since attenuation occurs both in the free gas and in the arc column. The effects of this attenuation on the temperature determinations may be accounted for by the use of an experimentally determined attenuation relationship given in the paper. The finally developed method yields temperature values to an accuracy of ± 2%. Experiments are described for carbon and tungsten arcs in air and nitrogen for currents up to 55 amperes and pressures up to 3 atmospheres. The values obtained range from 6200 to 7700° K and are in good agreement with values determined by other techniques.

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