파장이 다른 레이저의 임플란트 세정 효과에 관한 연구 박은경(Eun Kyeong Park); 양윤석(Yun Seok Yang); 이가람(Ka Ram Lee) ...
한국생산제조학회지,
08/2013, Letnik:
22, Številka:
4
Journal Article
This study applied a laser cleaning method (dry cleaning) that is used for cleaning semiconductor elements to dental implant cleaning. The lasers used in this study were pulsed fiber lasers with ...wavelengths of 1,064 and 532nm. The peak output, energy per pulse, energy density per pulse, time of pulse experiment, and number of pulse experiments served as process variables for this study, and the variables were changed for each experiment. As a result, a laser with a wavelength of 532 nm showed much higher cleaning efficiency than its 1,064 nm counterpart. As the wavelength range decreased,the quantized energy increased and the reflection rate of the titanium used for the implant decreased; consequently, the energy absorption rate increased.
Therefore, it is proposed that the energy density by wavelength has a greater influence on cleaning than does the output size. KCI Citation Count: 0
SM45C강의 온도변화에 따른 Nd:YAG 레이저 표면경화 특성 이가람(Ka-Ram Lee); 양윤석(Yun-Seok Yang); 황찬연(Chan-Youn Hwang) ...
한국생산제조학회지,
12/2012, Letnik:
21, Številka:
6
Journal Article
Laser surface hardening is one of core technologies to enhance various characteristics such as the strength, hardness,toughness, abrasion resistance, and fatigue resistance for the mold material. ...This paper focuses on testing characteristics of the laser heat treatment according to the preheating parameters in case of the SM45C medium carbon steel. In this paper,we assume that the power and travel speed of the laser are 1,800W and 0.5m/min, respectively, and the range of the preheating temperature is 50℃～300℃. From the result of the test, we observed that the hardness width and depth are enhanced as the temperature is increased. Also, the best average hardness was 751.7Hv for the temperature of 100℃. KCI Citation Count: 3
This paper focuses on the research of the anode and cathode in the Ni-MH secondary battery. In this paper, the proposed method employs a continuous wave Nd : YAG laser based on the pure Ni instead of ...the low carbon steel to improve the conductivity although the conventional secondary battery is based on the resistance spot welded with low carbon steel SS41. It welds a sandwich panel using the pure Ni and the porous thin plate, and the tested optimal conditions for the laser power and irradiation speed were 300 and 350 Watt, and 1.0～1.6m/min, respectively. Finally, we observed a ratio,heat input and cross-section and measured the conductivity of the welding section to test the weldability. KCI Citation Count: 1
With the development of advanced processing technology, laser processing systems, which require high-quality precision processing, have attracted considerable attention. Although laser equipment is ...expensive, it enables quick processing and less deformation of materials. This technology is often applied to secondary batteries, which has thus farinvolved the use of argon tungsten inert gas (TIG) welding. However, the welding characteristicsof argon TIG welding are not yet good, and a laser is used for welding to address this problem. In this study, lap-joint welding was conducted, and the desired welding characteristicswere obtained when the laser power was 1800W and the laser beam travel speed was 1.8 m/min. Lap-joint welding was conducted on Ni-coated SS41. Two cases were compared. No poreswere observed in the Ni-coated SS41 lap-joint welding part, and cracks appeared from the lap-joints. Moreover, the pole rod and tap were welded together in a T-joint form to improve the output of the secondary battery. T-joint laser welding showed better welding characteristics than TIG welding. KCI Citation Count: 2
Lap joint welding conducts low carbon steel plates using a 2.0kW continuous wave Nd:YAG laser beam. The specimen is composed of thin plate of 20 sheets. Process Variables contain two controlled ...parameters of the laser power and the welding speed. In order to quantitatively examine the characteristics of the lap welding, the welding quality of the cut section, stain-stress behavior, and the hardness of the welded part are investigated. The weld width difference between the top and the bottom because the welding speed is increased. The reason, cooling rate is decreased because of fast welding speed. When the heat input is higher, larger volume of the base metal will melt and the welding heat has longer time to conduct into the bottom from the top. The microstructure and tensile properties of the joints are investigated in order to analyze the effects of heat input on the quality of laser welded specimen. From the results of the investigation,We observe that welding quality is good for the laser power of 1800W, and laser welding speed from 1.8m/min to 2.2m/min. KCI Citation Count: 2
Lap joint welding conducts low carbon steel plates using a 2.0k W continuous wave Nd:YAG laser beam. The specimen is composed of thin plate of 20 sheets. The process variables consist of two ...controlled parameters of the laser power and the welding speed. In order to quantitatively examine the characteristics of the lap welding, the welding quality of the cut section, stain-stress behavior, and the hardness of the welded part are investigated. The difference in the weld width between the top and the bottom is because of the increase in welding speed. The decrease in the cooling rate is the result of a fast welding speed. When the heat input is higher, larger volume of the base metal melts and the welding heat has longer time to be conducted to the bottom from the top. The microstructure and tensile properties of the joints are investigated in order to analyze the effects of heat input on the quality of laser welded specimen. From the results of the investigation, the authors observe that welding quality is the optimum for the laser power of 1,800 W and laser welding speed from 1.8 m/min to 2.2 m/min.
자동차용 무침입형 극저탄소강의 파이버 레이저 용접에 대한 연구 오용석(Yong-Seok Oh); 신호준(Ho-Jun Shin); 양윤석(Yun-Seok Yang) ...
한국생산제조학회지,
06/2011, Letnik:
20, Številka:
3
Journal Article
The purpose of this paper is to describe experimental results about the butt welding and bead on plate welding of the high power Continuous Wave (CW) Fiber laser for Ultra-low carbon Interstitial ...Free(IF) steel plate for gear part of car.
After being welded of the gear parts by the fiber laser and electron beam Microstructures of melting zone had been mixed acicular, granular bainitic, quasi-polygonal and widmanstatten ferrite because of a radical thermal diffusion after welding,difference of critical volume and grain size. As a result of experiment, when gear parts were welded by the fiber laser and electron beam, the fiber laser welding has been stable properties without internal defects more than the electron beam welding. Therefore it has the very advantages of welding high quality and productivity more than conventional melting method. The optimal welding processing parameters for gear parts were as follows : the laser power and welding speed were 3kWatt, 30mm/sec respectively. At this time heat input was 21.2×103J/㎠. KCI Citation Count: 0
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