Fiber-coupled three-micron pulsed laser source for CFRP laser treatment

Author(s):  
Sebastian Nyga ◽  
David Blass ◽  
Veronika Katzy ◽  
Thomas Westphalen ◽  
Bernd Jungbluth ◽  
...  
Author(s):  
Florian Kuisat ◽  
Fernando Lasagni ◽  
Andrés Fabián Lasagni

AbstractIt is well known that the surface topography of a part can affect its mechanical performance, which is typical in additive manufacturing. In this context, we report about the surface modification of additive manufactured components made of Titanium 64 (Ti64) and Scalmalloy®, using a pulsed laser, with the aim of reducing their surface roughness. In our experiments, a nanosecond-pulsed infrared laser source with variable pulse durations between 8 and 200 ns was applied. The impact of varying a large number of parameters on the surface quality of the smoothed areas was investigated. The results demonstrated a reduction of surface roughness Sa by more than 80% for Titanium 64 and by 65% for Scalmalloy® samples. This allows to extend the applicability of additive manufactured components beyond the current state of the art and break new ground for the application in various industrial applications such as in aerospace.


1996 ◽  
Vol 63 (1) ◽  
pp. 77-80
Author(s):  
S. Guazzieri ◽  
W. Cecchetti ◽  
M. Meneguolo ◽  
G. D'incà ◽  
R. Bertoldin

— Laser treatment of benign prostatic hypertrophy (BPH) has gradually become more widespread over the last few years. In the USA it is considered an alternative to endoscopic resection as far as insurance payments are concerned. Different methods are used but the most common and suitable one for urologists is the removal and coagulation of the prostatic tissue under visual control (VLAP or ELAP). The Authors report their personal experience in this type of treatment where good results are due to: 1) combination of a powerful, stable laser source 2) durable side-emission contact fibre 3) laser resector, which also in the absence of epicystostomy maintains a good flow during the operation. However, “laser resection” should still be considered an experimental procedure to be used for randomised protocols or on selected patients (high risk of bleeding, Jehovah's witnesses, carriers of pace-maker, etc.).


1997 ◽  
Vol 12 (4) ◽  
pp. 320-327 ◽  
Author(s):  
E. J. Fiskerstran ◽  
K. Ryggen ◽  
L. T. Norvang ◽  
L. O. Svaasand

1979 ◽  
Vol 18 (15) ◽  
pp. 2555 ◽  
Author(s):  
D. A. Woodbury ◽  
T. A. Rabson ◽  
F. K. Tittel
Keyword(s):  

2006 ◽  
Vol 49 ◽  
pp. 56-61 ◽  
Author(s):  
Joseph J. Beltrano ◽  
Lorenzo Torrisi ◽  
Anna Maria Visco ◽  
Nino Campo ◽  
E. Rapisarda

A Nd:YAG laser is employed to ablate different materials useful in the bio-medical field. The laser source operates in the IR (1064 nm), VIS (532 nm) and UV (355 nm) regions with a pulse duration of 3-9 ns, a pulse energy of 3-300 mJ, a spot size of 1 mm2 and a repetition rate of 1- 30 Hz. Target material of interest are Titanium, Carbon, Hydroxyapatite (HA) and Polyethylene (PE). Laser irradiation occurs in vacuum, where hot plasma is generated, and thin films are deposited on near substrates. Generally, substrates of silicon, titanium, titanium-alloys and polymers were employed. Biocompatible thin films are investigated with different surface techniques, such as IR spectroscopy, Raman spectroscopy, XRD analysis and SEM investigations. Depending of the kind of possible application, films require special properties concerning the grain size, porosity, uniformity, wetting, hardness, adhesion, crystallinity and composition. The obtained results will be presented and discussed with particular regard to HA..


1981 ◽  
Vol 7 ◽  
Author(s):  
G. Battaglin ◽  
A. Carnera ◽  
G. Della Mea ◽  
P. Mazzoldi ◽  
Animesh K. Jain ◽  
...  

ABSTRACTWe present a comparative study (by 1.8 MeV 4He+ ion channeling) of virgin, self and Eu implanted single crystals of nickel, under irradiation with single ruby laser pulses. The as implanted Eu is nearly non-substitutional and remains so, even after laser treatment. The comparative defect dechanneling behaviour provides explicit evidence of defect-impurity interaction which may be suppressing the formation of an expected metastable solid solution in the Eu-Ni system, which possesses miscibility in the liquid phase. A clear surface Eu peak appears at 2.1 J/cm2.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mario Mordmüller ◽  
Viktoria Kleyman ◽  
Manuel Schaller ◽  
Mitsuru Wilson ◽  
Dirk Theisen-Kunde ◽  
...  

Abstract Laser photocoagulation is one of the most frequently used treatment approaches in ophthalmology for a variety of retinal diseases. Depending on indication, treatment intensity varies from application of specific micro injuries down to gentle temperature increases without inducing cell damage. Especially for the latter, proper energy dosing is still a challenging issue, which mostly relies on the physician’s experience. Pulsed laser photoacoustic temperature measurement has already proven its ability for automated irradiation control during laser treatment but suffers from a comparatively high instrumental effort due to combination with a conventional continuous wave treatment laser. In this paper, a simplified setup with a single pulsed laser at 10 kHz repetition rate is presented. The setup combines the instrumentation for treatment as well as temperature measurement and control in a single device. In order to compare the solely pulsed heating with continuous wave (cw) tissue heating, pulse energies of 4 µJ were applied with a repetition rate of 1 kHz to probe the temperature rise, respectively. With the same average laser power of 60 mW an almost identical temporal temperature course was retrieved in both irradiation modes as expected. The ability to reach and maintain a chosen aim temperature of 41 °C is demonstrated by means of model predictive control (MPC) and extended Kalman filtering at a the measurement rate of 250 Hz with an accuracy of less than ±0.1 °C. A major advantage of optimization-based control techniques like MPC is their capability of rigorously ensuring constraints, e.g., temperature limits, and thus, realizing a more reliable and secure temperature control during retinal laser irradiation.


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