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- In this paper an analytical model for prediction of angular deformation is presented. In this model convective heat losses and a multipoint distributed heat source is used for determination of the inherent strain zone which causes the bending angle. The effects of laser bending process parameters including laser power, beam diameter, scan velocity and pulse duration on the bending angle were investigated experimentally. Main effects of factors were considered and the regression line was derived. An L9 Taguchi’s standard orthogonal array was employed as experimental design and the level of importance of the laser bending process parameters on the bending angle was determined using analysis of variance (ANOVA). Comparison of the analytical model and experimental results has shown a reasonable agreement.

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In hydromechanical deep drawing process, the traditional matrix is replaced by pressurized fluid, and the final shape is determined based on the shape of a rigid punch. It is required to change the fluid pressure within the allowed working zone during the process to prevent the workpiece from rupturing and wrinkling,. Working zone curve represents the range of maximum available drawing ratios without rupture under the highest chamber pressure. In this paper, hydromechanical deep drawing of square cups made of aluminum-steel double layer sheets are studied by experiments and finite element simulations. In order to detect the rupture onset in simulations, experimental forming limit diagrams were obtained using for aluminum/steel double layer sheet. Experimental data were used to validate the finite element model. The effects of process parameters such as thickness of the various layers, prebulge pressure, chamber pressure and the friction coefficient were investigated on the working zone and the process window. The numerical results show that an optimum amount for the drawing ratio exists for each prebulge pressure. Also, with increasing the chamber pressure, shrinkage is reduced on the flange area. With increasing the friction between the sheet and matrix or the sheet and blank-holder, working zone becomes smaller; while with increasing the friction between the sheet and the punch it becomes larger. Experiments were performed for different drawing ratios to evaluate the numerical results, in which a good agreement was observed.

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Nowadays, multilayered sheet metals are used in order to achieve a wide range of favorite mechanical, physical, thermal and electrical properties. The laser beam passage over the sheet creates extreme temperature changes which can lead to a change in chemical properties and microstructures. Due to the wide application of these materials in chemical and corrosive environments, corrosion tests were carried out on two-layered SUS304L/copper C11000 and three-layered SUS430/copper C11000/steel SUS430 sheets subjected to various laser passes. Ytterbium fiber laser is used and the governor mechanism during the process is TGM. The changes of microstructures were revealed by metallography. Corrosion resistance of steel layer in three-layered sheet subjected to laser was dropped due to the martensite and oriented ferrite grain size reduction in HAZ. There is no change in microstructure and corrosion behavior of copper layer and the second steel layer due to the HAZ low penetration depth. There is no change in microstructure and corrosion behavior of steel layer in two layered sheet due to the austenitic microstructure. Penetration depth of HAZ in two-layered sheet is limited to a small part of its steel cross section. So, there is no change in microstructure and corrosion behavior of copper, and corrosion is the same all over the copper layer in all specimens.