The effect of the distance shift between the beam axis and the steel/copper interface line was investigated. The shift distance towards the copper was considered as a negative value and towards the steel as a positive. Cho, W.I.; Na, S.J.; Thomy, C. Numerical simulation of molten pool dynamics in high power disk laser welding. J. Mater. Process. Technol. 2012, 212, 262–275. [ Google Scholar] [ CrossRef] Pang, S.Y.; Chen, X.; Zhou, J.X. 3D transient multiphase model for keyhole, vapor plume, and weld pool dynamics in laser welding including the ambient pressure effect. Opt. Lasers Eng. 2015, 74, 47–58. [ Google Scholar] [ CrossRef]

Pang, S.Y.; Chen, L.L.; Zhou, J.X. A three dimensional sharp interface model for self consistent keyhole and weld pool dynamics in deep penetration laser welding. J. Phys. D Appl. Phys. 2011, 44, 025301. [ Google Scholar] [ CrossRef] Zhou, K.; Cai, L.L. Online Nugget Diameter Control System for Resistance Spot Welding. Int. J. Adv. Manuf. Technol. 2013, 68, 2571–2588. [ Google Scholar] [ CrossRef]In this paper, a deep learning based on processing the monitoring system by a high-speed camera and MATLAB image processing was proposed for laser welding [ 22]. The experimental analyses were performed in several phases. The cross-sections of welds were polished and etched with Béchet–Beaujard solution. To know the impact of the parameters on the molten zone (MZ), the shape of the weld was observed using a Binocular microscope (Wild M420, Leica) and measured using the software controlling the camera (LC 120 HD Leica). First, this process allowed an approximation of the Cu dilution in the MZ: the parting was resituated with lines engraved on both sides. The ratio of the copper melt width and the width of the MZ gives an approximation of the composition by volume of the MZ. The widths at the top, middle, and bottom of the MZ and its surface were measured on the transverse cuts. Second, it allowed the measurement of the final MZ length (M.L), width (M.W), and area (M.A), which were used to validate the following image processing. 3. Image Treatment Methodology There are many applications for the dissimilar copper/stainless steel welding like the chemical industries, power generation, electric, electronic, and cryogenics. It is very useful in the case of resulting hybrid products which merge the excellent electric and thermal conductivity of copper with essential weight and cost saving [ 4]. Li, S.C.; Chen, G.Y.; Katayama, S.J. Relation between spatter formation and dynamic molten pool during high-power deep-penetration laser welding. Appl. Surf. Sci. 2014, 303, 481–488. [ Google Scholar] [ CrossRef] These calculations indicate that the surface tension pressure for copper ( P s.c) is less than that for steel ( P s.s), which may be the direct reason for the elongation of the rear keyhole surface towards the copper more than the steel as this force is responsible for the keyhole curvature closing. 5.2. Effect of Welding Speed

Also, laser beam energy absorption and optimization of the laser welding method is the subject of many previous studies [ 6– 8], particularly in the case of dissimilar welding [ 9, 10]. Assuncao et al. studied the behavior of different metals under laser welding in the transition from conduction to keyhole modes [ 6]. Their experiments showed that the thermal properties (thermal conductivity, melting and vaporization temperatures, and specific heat) of the materials have the most important role in the transition between laser welding modes. Sibillano et al. developed a real-time monitoring technique based on the analysis of the plasma plume optical spectra generated during laser welding to determine the laser welding mode [ 11]. A simplified sketch keyhole geometry of steel/copper welding for different laser power where f s and r s are the front and rear keyhole wall for steel, respectively, and f c and r c are the front and rear keyhole wall for copper, respectively. Battery Powered:Lights need the power to work properly. The source of power can be the electricity of your home from wires or built-in batteries. If you are easy to install the wires with the lamp, then you can consider any device that gets power directly from home electric wires this will assist you to rid of charging the lamp again and again.The corrosion resistance of stainless steel and heat conductivity of copper are required for the heat exchangers fabrications. The welding of stainless steel and copper is essential to manufacturing these constructs. However, the dissimilar welding of stainless steel and copper still has many difficulties. The first difficulty is the large differences of physical properties between the stainless steel and copper like melting point, thermal conductivity, and thermal expansivity. These physical differences make the conventional welding methods difficult in dissimilar welding. In this work, the laser beam welding method is used to avoid these problems [ 5]. For 2 m/min, 2.5 m/min (left), and 3 m/min (right), where f s and r s are the front and rear keyhole walls for steel, respectively. The copper front keyhole wall is f c and the copper rear keyhole wall is r c. 5.3. Effect of Laser Shift Real weld seam for copper/steel metals and the extracted keyhole and weld pool geometry for different shift distances from the initial joint plan. (a) −200 μm, (b) −100 μm, (c) 0 μm, (d) +100 μm, (e) +200 μm, (f) +300 μm, (g) +400 μm, and (h) +500 μm, where the negative shifts indicate a shift towards the copper side. 6. Conclusion Zhao, S.S.; Yu, G.; H, X.L. Numerical simulation and experimental investigation of laser overlap welding of Ti6Ai4V and 42CrMo. J. Mater. Process. Technol. 2011, 211, 530–537. [ Google Scholar] [ CrossRef] Motion Sensor:keyhole motion sensing light,Sensitive motion detective sensor, opening door in dark is so easy, Using Advanced PIR sensing technology,

Naito, Y.; Katayama, S.; Matsunawa, A. Keyhole behavior and liquid flow in molten pool during laser arc hybrid welding. Proc. SPIE. 2003, 3888, 34–45. [ Google Scholar] [ CrossRef] a) Schematic of laser dissimilar metals welding experimental setup. (b) Extracted the original image of the weld pool [ 19].

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Figure 12 shows that the keyhole area, length, and width match parallel to each other and that all three increase from 1 to 4 kW within laser speed ( V = 2 m/min) which leads to increase of all keyhole dimensions, with increasing laser power to reach a saturated region at 5 kW. This may be because of the increases of keyhole opening (M.A) which leads to more laser radiation loss. Wu, D.Y.; Hua, X.M.; Fang, L. Understanding of spatter formation in fiber laser welding of 5083 aluminum alloy. Int. J. Heat Mass Transfer. 2017, 113, 730–740. [ Google Scholar] [ CrossRef] Zhou, J.; Tsai, H.L. Investigation of mixing and diffusion processes in hybrid spot laser-MIG keyhole welding. J. Phys. D Appl. Phys. 2009, 42, 095502. [ Google Scholar] [ CrossRef] Energy Saving Mini and elegant appearance; Environment protective material, flexibility and bright.Energy saving and long service life.LED light source is completely green, no pollution. Low-Carbon,Saving energy.