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Experimental Investigation on Micro Drilling of Thin Sheets using Nd:YAG Laser
Suman Chatterjee,Dongkyoung Lee,Siba Sankar Mahapatra 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11
With the growth in technological advancements, miniaturization of the products increases and showing the effect on the day-to-day life of people. There is the widespread application of micro-machined products in heat exchangers for micro-electronic products, micro-nozzle systems, micro-electromechanical systems (MEMS), micro-molds and micro-fluidic systems, and battery manufacturing, etc. In the present study, laser drilling of stainless steel and titanium alloy has been performed using Nd:YAG laser under identical experimental conditions. The study illustrates the parametric effect of laser such as pulse width, laser current, pulse frequency, and gas pressure on performance measures such as circularity at entry and exit, taper, and spatter area during laser micro drilling process for both the materials. The study has adopted the design of experiment (DOE) so that maximum process related information can be gathered from less experimental trials. Micrograph analysis has been performed to identify the quality of micro-holes.
Suman Chatterjee,Lanh N. Trinh,이동경 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8
Laser beam welding (LBW) has found wide applications in several fields, including electronics, aerospace, and automobile industries, owing to its inherent capabilities over existing welding techniques. Dissimilar laser welding is one of the challenging fabrication processes. However, joining of different materials poses challenging issues because material properties of each material interacts to give rise to hybrid system performance. In present study weld of Al-Cu and Cu-Al has been performed using Ytterbium pulsed fibre laser with a maximum laser power of 300 W. The scanning electron microscope (SEM), and energy dispersive x-ray spectroscopy (EDS) has been employed to investigate the microstructural and chemical composition of the welded joints. The EDS analysis showed the presence of possible intermetallic compounds (IMCs) like AlCu and Cu2Al in the fusion zone. The Al-Cu and Cu-Al welded joints had maximum shear strength of 295 N and 84 N, respectively. The results showed the efficacy of Al-Cu joints over Cu-Al joints. The study further demonstrated that the Al-Cu weld had a better microstructure with fewer pores and cracks than the Cu-Al welds by varying the laser powers.
나노초 레이저의 표면 처리를 이용한 SM490A 젖음성 변화 연구
백승은(Seungeun Baek),서영진(Youngjin Seo),박동규(Dongkyu Park),Mang Muan Lian,Feyisola Idowu Nana,Tam Van Huynh,성민철(Mincheoul Seong),전수빈(Subin Jeon),Suman Chatterjee,이동경(Dongkyoung Lee) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11
According to the power of the nanosecond laser, the SM490A surface is irradiated in a grid pattern. After laser irradiation, the microstructure appears at a power of more than 6 W. At 6 W, relatively uniform grid pattern microstructures appear, but as laser power increases, the microstructure changes due to the high thermal effect. When the contact angle is measured with time, superhydrophilicity appears immediately after laser irradiation, but the contact angle increases with time. It becomes hydrophobic in 10~15 days, and a contact angle of 140° at 6 W appears in 30 days. When the contact angle is observed according to power, hydrophilicity appears at 2 W, 4 W without microstructure. Hydrophobicity appears at power above 6 W with microstructures. The highest contact angle appears at 6W with uniform microstructure.
SPFH590에 대한 레이저 클리닝 중 레이저 파라미터가 미치는 영향
성민철(Mincheoul Seong),서영진(Youngjin Seo),Mang Muan Lian,Feyisola Idowu Nana,Tam Van Huynh,백승은(Seungeun Baek),전수빈(Subin Jeon),Suman Chatterjee,박동규(Dongkyu Park),이동경(Dongkyoung Lee) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11
Welding applies to variety of fields, such as joining steel materials used in automotive body materials. However, CO2 MIG welding has a problem of forming an oxide film, which results in heat tinting and oxide layers due to high heat. The oxide layers due to high heat. The oxide film that occurs reduces corrosion resistance of steel materials and affects the remaining life of the painting when painting the automotive. The experiment was conducted with a 20W laser to remove the oxide film of the weld hit tint was also removed, but slag was not removed. To solve this problem, we conducted a 200W laser cleaning experiment by increasing laser power. After the experiment, the microstructure and chemicals were observed using SEM/EDX to analyze the interaction properties of laser parameter power and materials. Geometry equipment was also used to observe surface roughness. Experiments show that as power increased, oxygen decreased and iron increased. Therefore, it is determined that the stronger the laser power, the greater the degree of cleaning.