Comparative Research on the Quality of Micro Hole in Superalloy GH2135 and Stainless Steel 420J1 by Laser Processing

2016 ◽  
Vol 703 ◽  
pp. 27-33
Author(s):  
Liang Wang ◽  
Nai Fei Ren ◽  
Yun Long Wang ◽  
Lin Zhong Zhu
Keyword(s):  
Stainless Steel ◽  
Pulse Energy ◽  
Laser Processing ◽  
Pulse Width ◽  
Laser Scanning ◽  
Short Pulse ◽  
Test Method ◽  
Repetition Frequency ◽  
Orifice Diameter

Both superalloy GH2135 and stainless steel 420J1 were used as test materials to be processed by LASERTEC 80 PowerDrill three-dimensional solid laser processing center. The microstructure of the hole was investigated by super depth of field microscope and laser scanning microscope. The front and back orifice diameter, orifice deposits and thermal effect of accumulation zone were studied. The single factor test method was used to study the influence of pulse energy, pulse width and repetition frequency on the quality of micro holes. The results showed that the front and back diameter of the holes all increase with the increase of pulse energy from 0.4J-3.9J. And the front and back aperture are increase with the increase of pulse width from 0.9ms-1.9ms. Meanwhile, the variation of the aperture and pore taper is more noticeable with the repetition frequency changed from 10Hz-60Hz. The results revealed that pulse energy is one of the biggest influence factors, large pulse energy can lead to small hole taper within a certain range, and short pulse width can reduce orifice debris and splash. Both the recast layer and microcrack were existed in the two kinds of metal materials. The quality of holes drilling in GH2135 is better than 420J1.

Study on Laser Welding of Phone Nuts

2013 ◽  
Vol 815 ◽  
pp. 778-781
Author(s):  
Xiao Hong Wu
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Laser Pulse ◽  
Laser Welding ◽  
Pulse Energy ◽  
Pulse Width ◽  
Peak Power ◽  
Laser Pulse Energy ◽  
304 Stainless Steel ◽  
Power Pulse

Used YAG pulse laser to weld 304 stainless steel nuts, studied about the parameters such as peak power, pulse width, defocus distance impacting on the performance of the joints welded by laser. The studies showed that the tensile strength and torque of the nuts increased as the peak power and the pulse width increased.Burn through in welding easy occur when laser pulse energy is too big, pulse width is too wide or defocus distance is too low.

Laser Beam Shapers Applied in the Laser Micro-Jet Processing

2010 ◽  
Vol 29-32 ◽  
pp. 1925-1929 ◽  
Author(s):  
Xi Zhao Lu ◽  
Chun Lin ◽  
Zhen Heng Lin ◽  
Yuan Qing Huang
Keyword(s):  
Laser Beam ◽  
Laser Processing ◽  
Pulse Width ◽  
Total Internal Reflection ◽  
Light Guide ◽  
Optical Path ◽  
Beam Laser ◽  
Air Interface ◽  
International Patent

With respect to the methods of precise processing, the laser micro-jet system became a hot topic in recent years. In this paper, inverted Galileo telescope would reform the laser beam of Gaussian distribution into a flat-topped distribution spot, micro-jet is adopted in order to achieve a processing sharp cutter which owned the characterize of more sharp to process. It should be a reformed laser water micro-jet processing. The experiment of laser micro-jet was carried out to make reliable proof. The design of optical path integrated the Galileo shaper would reduce the pulse width under the safe circumstance. The quality of working laser beam was improved with compressing the width of flat-topped of laser beam. Laser micro-jet processing is an international patent technique which was developed by Dr. Bernold Richerzhagen in 1998[1]. During the laser processing, laser micro-jet could be used as light guide, which dues to the total internal reflection at the water-air interface [2.]

scholarly journals Deburring Method of Aluminum Mould Produced by Milling Process for Microfluidic Device Fabrication

2021 ◽  
Vol 6 (1) ◽  
pp. 123-140
Author(s):  
Kushendarsyah Saptaji ◽  
Farid Triawan ◽  
Tong Keong Sai ◽  
Asmelash Gebremariam
Keyword(s):  
Stainless Steel ◽  
Microfluidic Device ◽  
Laser Scanning ◽  
Optical Microscope ◽  
Milling Process ◽  
Device Fabrication ◽  
Ductile Metals ◽  
Slot Milling ◽  
Micro Scale

The existence of top burrs in micro-scale features produced by milling process can deteriorate the surface quality of a product. Ductile metals, such as aluminum alloys, are prone to suffer from top burrs formation after a slot-milling process. A brief review on the state-of-the-art of burr removal process in micro-scale milling is provided in this paper. Various deburring methods were reportedly able to remove the burrs in micro-scale features, however a much simpler method is still needed. In the present work, a deburring process by stainless steel end brushing is introduced for aluminum mould used in microfluidic device fabrication. The micro-scale features are produced by slot-milling process followed by the deburring process. The deburred moulds are then visually observed using optical microscope and Scanning Electron Microscope (SEM) and the average surface roughness and its features profile are measured using 3D Laser Scanning Confocal Microscope. As a result, the proposed deburring method can successfully remove the top burrs, as indicated by a height reduction of about 21% due to the removal action by the brush. Hence, a burr-free embossing mould with complex shape channel features can be produced by milling and by applying a simple deburring process using stainless steel end brush.

scholarly journals Pulsed LD side-pumped MgO: LN electro-optic cavity-dumped 1123 nm Nd: YAG laser with short pulse width and high peak power

2018 ◽  
Vol 6 ◽  
Author(s):  
Yang Bai ◽  
Bing Bai ◽  
Diao Li ◽  
Yanxiao Sun ◽  
Jianlin Li ◽  
...  
Keyword(s):  
Pulse Energy ◽  
Repetition Rate ◽  
Pulse Width ◽  
Peak Power ◽  
Optimization Design ◽  
Short Pulse ◽  
High Peak ◽  
High Peak Power ◽  
Electro Optic ◽  
Energy Pulse

We report a cavity-dumped 1123 nm laser with narrow pulse width and high peak power by an MgO: LN crystal electro-optic (EO) modulator. Based on the structural optimization design of a folded biconcave cavity using the 808 nm pulsed laser diode (LD) side-pumped ceramic Nd: YAG rod, output pulses with maximum pulse energy and peak power up to 39.6 mJ and 9.73 MW were obtained, corresponding to 100 Hz repetition rate and 4.07 ns pulse width. The instabilities of pulse width and pulse energy were $\pm$1.55% and $\pm$2.06%, respectively. At the highest repetition rate of 1 kHz, the pulse energy, pulse width, and peak power were 11.3 mJ, 5.05 ns, and 2.24 MW, respectively. The instabilities of pulse width and pulse energy were $\pm$2.65% and $\pm$3.47%, respectively.

Study on the Laser Precision Cutting System and Stainless Steel Microporous Cutting Technology

2015 ◽  
Vol 817 ◽  
pp. 342-347 ◽  
Author(s):  
Shan Guo Han ◽  
De Tao Cai ◽  
Zi Yi Luo ◽  
De Jun Yan ◽  
He Xin Chen ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Laser Power ◽  
Laser Cutting ◽  
Pulse Width ◽  
Gas Pressure ◽  
Steel Plates ◽  
Line Angle ◽  
Auxiliary Line ◽  
Cutting System

In order to improve the quality of laser cutting of stainless steel porous, the investigation on cutting 0.12mm stainless steel plates was carried out by a50W-powerbridgefiber laser cutting machine.The influence of the auxiliary line angle, laser power, and the pulse width and gas pressure on the cutting quality was studied in this paper.The results show that fewer defects was found on the samples when the cutting angle of auxiliary line was 90°and few splash orburrswas found on the samplesby 40 Wlaser power, with 56 μs pulse width and 1.3MPa gas pressure.

scholarly journals Review on Experimental and Theoretical Investigations of Ultra-Short Pulsed Laser Ablation of Metals with Burst Pulses

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3331
Author(s):  
Daniel J. Förster ◽  
Beat Jäggi ◽  
Andreas Michalowski ◽  
Beat Neuenschwander
Keyword(s):  
Laser Processing ◽  
Short Pulse ◽  
Theoretical Investigations ◽  
New Process ◽  
Multiple Pulses ◽  
Processing Regimes ◽  
Ultra Short Pulse ◽  
Machining Strategies ◽  
Physical Phenomena

Laser processing with ultra-short double pulses has gained attraction since the beginning of the 2000s. In the last decade, pulse bursts consisting of multiple pulses with a delay of several 10 ns and less found their way into the area of micromachining of metals, opening up completely new process regimes and allowing an increase in the structuring rates and surface quality of machined samples. Several physical effects such as shielding or re-deposition of material have led to a new understanding of the related machining strategies and processing regimes. Results of both experimental and numerical investigations are placed into context for different time scales during laser processing. This review is dedicated to the fundamental physical phenomena taking place during burst processing and their respective effects on machining results of metals in the ultra-short pulse regime for delays ranging from several 100 fs to several microseconds. Furthermore, technical applications based on these effects are reviewed.

scholarly journals A randomized crossover trial of short versus conventional pulse width DBS in Parkinsons Disease

2021 ◽  
Author(s):  
Jan Niklas Petry-Schmelzer ◽  
Lisa Marie Schwarz ◽  
Hannah Jergas ◽  
Paul Reker ◽  
Julia K. Steffen ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Pulse Width ◽  
Short Pulse ◽  
Symptom Control ◽  
Motor Symptom ◽  
Randomized Crossover Trial ◽  
Short Pulse Width ◽  
Stn Dbs ◽  
Deep Brain

Background: Subthalamic nucleus deep brain stimulation is a well-established treatment for patients with Parkinson`s disease. Previous acute challenge studies suggested that short pulse widths might increase the therapeutic window while maintaining motor symptom control. Objectives: To investigate in patients with Parkinson`s disease and nucleus subthalamicus deep brain stimulation (STN-DBS) whether short pulse width stimulation with 30μs maintains equal motor control as conventional 60μs stimulation over a period of 4 weeks. Methods: In this monocentric, double-blinded, randomized crossover trial, 30 patients with Parkinson`s disease and STN-DBS were enrolled and assigned to 4 weeks of stimulation with 30μs and 4 weeks of stimulation with 60μs in randomized order (German Clinical Trials Register No. DRKS00017528). The primary outcome was the difference in motor symptom control as assessed by a motor diary. Secondary outcomes included energy consumption measures, non-motor effects, side-effects, and quality of life. Results: A total of 24 patients were included in the final analysis. There was no difference in motor symptom control between the two treatment conditions. Concerning secondary outcomes there was no difference in energy consumption, non-motor symptoms, side-effects, or quality of life. On the individual level, patients preferring 30μs tended to be more dyskinetic in the 60μs setting, whereas patients preferring 60μs experienced more off-time in the 30μs setting. Conclusions: Short pulse width settings (30μs) provide equal motor symptom control as conventional (60μs) stimulation without significant differences in energy consumption. Future studies are warranted to evaluate a potential benefit of short pulse width settings in patients with pronounced dyskinesia.

Passively Q-switched Nd:YAG ceramic laser towards large pulse energy and short pulse width

Laser Physics ◽  
2009 ◽  
Vol 20 (1) ◽  
pp. 187-191 ◽  
Author(s):  
R. Lan ◽  
Z. Wang ◽  
H. Liu ◽  
H. Yu ◽  
L. Guo ◽  
...  
Keyword(s):  
Pulse Energy ◽  
Pulse Width ◽  
Short Pulse ◽  
Short Pulse Width ◽  
Ceramic Laser ◽  
Large Pulse

Characterization of micro hole on super alloy GH4037 and stainless steel 304 by millisecond-pulsed Nd:YAG laser processing

2021 ◽  
Vol 11 (12) ◽  
pp. 1975-1987
Author(s):  
Liang Wang ◽  
Rong Guan ◽  
Qunyong Zhang ◽  
Kaibo Xia ◽  
Naifei Ren
Keyword(s):  
Stainless Steel ◽  
Pulse Duration ◽  
Pulse Energy ◽  
Recast Layer ◽  
Stainless Steel 304 ◽  
Micro Holes ◽  
Micro Hole ◽  
Simulation Results ◽  
Super Alloy

In this study, both super alloy GH4037 and stainless steel 304 were selected as experimental materials to be processed by LASERTEC 80 PowerDrill three-dimensional solid laser machining center. The structure of the micro hole was researched by 3D Laser Scanning Confocal Microscope and Scanning Electron Microscope (SEM). Meanwhile, The holes taper, entrance and exit ends diameter, microcrack, recast layer, orifice deposits and the heat affected zone (HAZ) were also investigated. The single factor experimental method was used to research the influences of defocusing amount, pulse energy, repetition frequency, and pulse duration on quality of micro holes. Experimental results indicated that the holes entrance and exit ends diameter enlarged with increased pulse energy from 3.4 J to 4.2 J. The entrance and exit ends diameter of holes decreased with increased pulse duration from 0.5 ms to 2.5 ms. Besides, the variation of holes diameter and taper were more obvious with repetition frequency changing from 10 Hz to 30 Hz, and variation range for the entrance and exit ends diameters and taper were not obvious with increased defocusing amount from −2 mm to 2 mm. The herein results indicated that pulse energy was one of the most significant influencing elements, and higher pulse energy could bring about lower hole taper within a certain range. Meanwhile, shorter pulse duration reduced splash and debris of holes surface. The recast layer, micro crack and HAZ were existed in the both kinds of experimental materials. Moreover, the microcrack and recast layer on holes wall of GH4037 were less than those of 304, and the HAZ in drilling hole for GH4037 was more than that of 304. The experimental results for the holes size were compared with corresponding simulation results under different defocusing amount respectively, which verified the accuracy of simulation results. Combining the above factors, the quality of micro holes drilling on super alloy GH4037 was better than stainless steel 304.

Study on Measurement of Melting Process of Molten Pool Formed by Laser Scanning Mirror

2008 ◽  
Vol 392-394 ◽  
pp. 141-145 ◽  
Author(s):  
Y.S. Wang ◽  
Juan Juan Wang ◽  
J.B. Lei ◽  
Xi Chen Yang
Keyword(s):  
Temperature Distribution ◽  
Laser Processing ◽  
Molten Pool ◽  
Laser Scanning ◽  
Melting Process ◽  
Scanning Time ◽  
Laser Focusing ◽  
On Line ◽  
Computer Numerical Simulation

The profile and temperature distribution of laser molten pool are mainly factors which have directly effect on quality of laser processing (laser melting and laser cladding). It is very necessary to study measurement method of melting process in laser molten poo1 on-line, for improving processing design and inspecting laser processing quality. A system of dynamic process measurement for laser molten pool was developed. The melting process of laser scanning molten pool formed by high power CO2 Laser was measured. Its temperature distribution was analyzed by special analysis software. It was shown that a section of integrated molten pool would come into being in the middle of the laser scanning line spot after a period of scanning time, and then the molten pool got increased in length with the time, and a little increased in width at the same time, the result was consistent with that of computer numerical simulation. Compared with laser focusing spot, laser scanning spot was more uniform in temperature distribution, that could be propitious to improve the quality of laser processing.

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