scholarly journals Experiment Study of Rapid Laser Polishing of Freeform Steel Surface by Dual-Beam

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 324 ◽  
Author(s):  
Yongquan Zhou ◽  
Zhenyu Zhao ◽  
Wei Zhang ◽  
Haibing Xiao ◽  
Xiaomei Xu
Keyword(s):  
Laser System ◽  
Pulsed Laser ◽  
Freeform Surface ◽  
Initial State ◽  
Laser Polishing ◽  
Beam Laser ◽  
Dual Beam ◽  
Series Of Experiments ◽  
Five Axis ◽  
Polishing Efficiency

One of the challenges regarding widespread use of parts made from alloy steel is their time-consuming polishing process. A rough freeform surface of part has been often expected to be polished rapidly up to a smooth surface finish. The focus of this study is to develop a fast polishing method of freeform surface by using dual-beam lasers. The dual-beam laser system consists of continuous laser (CW) and pulsed laser based on a five-axis CNC device. In this study, a series of experiments of CW laser polishing present the effects of different spot irradiation on surface topography, then the combination trajectory of zigzag and square waveform of pulsed laser is explored to realize a “melting peak for filling into valley” (MPFV) method. The polishing experiment on a semisphere of S136H steel polished by dual-beam shows that a rough semisphere surface was rapidly polished from initial state value of Sa (=877 nm) to post-polished value of Sa (=142 nm), and the polishing efficiency is as high as 2890 cm2/H.

Investigations of Femtosecond-Nanosecond Dual-Beam Laser Ablation of Dielectrics

2009 ◽  
Author(s):  
Z. H. Rao ◽  
C. H. Lin ◽  
L. Jiang ◽  
W. J. Tsai ◽  
P. H. Wu ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Laser Pulse ◽  
Laser Energy ◽  
Removal Rate ◽  
Laser System ◽  
Domain Model ◽  
Beam Laser ◽  
Temporal Domain ◽  
Dual Beam ◽  
Fs Laser

A multi-scale (in temporal domain) model was developed to study the ablation of dielectrics using a femtosecond (fs)-nanosecond (ns) dual-beam laser system. The model is an integration of the plasma model and improved two-temperature model for the fs laser ablation, and Fourier’s law for the ns laser ablation. The model is used to investigate the ablation for dielectrics when a fs pulse is shot at the peak of a ns pulse. It is found that the fs laser pulse can result in the increase of absorption of the ns laser energy, leading to a much higher material removal rate as compared to fs laser ablation alone or ns laser ablation alone. The enhancement of ns laser energy absorption is caused by the increased electron density and the formation of a tiny crater in the material created by the fs laser pulse. The corresponding experiment using a Ti:Sapphire fs laser (Legend-F, Coherent) and a Nd:YAG ns UV laser (Avia-X, Coherent) was also conducted and the results are consistent with the modeling predictions.

scholarly journals Qualification of Operational Amplifier used in Satellite Subsystem using Picosecond Pulsed Laser System

2020 ◽  
Vol 9 (2) ◽  
pp. 523-527
Keyword(s):  
Cross Section ◽  
Operational Amplifier ◽  
Second Harmonic ◽  
Laser System ◽  
Threshold Energy ◽  
Pulsed Laser ◽  
Spot Size ◽  
Single Event ◽  
532 Nm ◽  
Pulsed Laser Irradiation

Picosecond Pulsed Laser System (PPLS) was used to simulate the single event effects (SEE) on satellite electronic components. Single event transients effect induced in an operational amplifier (LM324) to determine how transient amplitude and charge collection varied with pulsed laser energies. The wavelength and the focused spot size are the primary factors generating the resultant charge density profile. The degradation performance of LM324 induced by pulsed laser irradiation with two wavelength (1064nm, 532nm) is determined as a function of laser cross section. The transient voltage changed due to pulsed laser hitting specific transistors. This research shows the sensitivity mapping of LM324 under the effect of fundamental and second harmonic wavelengths. Determine the threshold energy of the SET in both wavelength, and compare the laser cross section of 1064 nm beam and 532 nm beam.

Growth and characterization of dual-beam pulsed-laser-deposited Zn1−xCoxO thin films

2005 ◽  
Vol 98 (11) ◽  
pp. 114909 ◽  
Author(s):  
Y. Z. Peng ◽  
T. Liew ◽  
T. C. Chong ◽  
W. D. Song ◽  
H. L. Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser ◽  
Dual Beam

scholarly journals Determination of the imploded mass in laser-imploded shell targets

1986 ◽  
Vol 4 (3-4) ◽  
pp. 507-514 ◽  
Author(s):  
S. Denus ◽  
J. Farny ◽  
M. Grudzień ◽  
W. Mróz ◽  
J. Wołowski ◽  
...  
Keyword(s):  
Neutral Atom ◽  
Neutral Particle ◽  
Laser System ◽  
Semiconductor Diode ◽  
Velocity Spectrum ◽  
Particle Detector ◽  
Beam Laser ◽  
Atom Flux ◽  
Time Of Flight Method

A new method of experimental measurement of the imploded mass of laser-imploded shell targets is proposed. This method is based on simultaneous measurements of the velocity spectrum of the neutral atom flux emitted from the imploded part of the target, and the total energy carried by them. A semiconductor diode with a shallowly located p – n junction was used as the low energy neutral particle detector. By means of the time of flight method neutral atom fluxes with velocities υ ∼ (0·6 − 1·8) × 107cm/s were registered in experiments carried out on the 6-beam laser system “Delfin”.

Diamond Turning Freeform Optics

2007 ◽  
Vol 364-366 ◽  
pp. 1-6
Author(s):  
W. Jiang ◽  
Bill Tse ◽  
Roy Louie ◽  
Frankie Chan
Keyword(s):  
Diamond Turning ◽  
Freeform Surface ◽  
Work Piece ◽  
Freeform Optics ◽  
Milling Method ◽  
Slow Tool Servo ◽  
Optics Industry ◽  
Optics Fabrication ◽  
Five Axis ◽  
Machining Parameter

Freeform optics fabrication has become one of the hottest topics in optics industry in recent years. Although it still remains a challenge, many have tried different ways of manufacturing it. Some have achieved degrees of success. By means of a Nanotech 350-FG five axis diamond turning machine, we too have successfully produced some prototype freeform optics and lens arrays with Slow Tool Servo and Milling method. The produced freeform optics are mainly for automobile LED headlamps and the lens arrays are for LED illumination. In order to produce the freeform optics, we developed our own DT Slow Tool Servo program which is capable of generating a DT program for diamond turning a universal/general 3D freeform surface. Slow Tool Servo technique and Diamond Milling technique were mainly employed to produce these freeform surfaces. The manufacturing process and machining parameter details will be given in the paper. The two main methods we used will be compared and discussed as well. In measuring the freeform surface, a 3D white light interferometer was used to scan and obtain the surface coordinates. The software made by ourselves enabled us to compare the measure results of the work piece with that of the design drawings. The deviation of our finished forms is within 5 um from that of the nominal. The surface quality Rq is about 10 nm. Measuring equipment and methodology will also be discussed in the paper.

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