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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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Laser Forming (LF) process is one of the thermal forming processes; which uses laser beam irradiation as a forming factor. In this process, temperature gradient along the sheet thickness produces the final bending angle. So far, various investigations are carried out on laser forming of low carbon steel sheets. However, LF process can be utilised in other metallic and non-metallic sheets. High surface reflectivity and thermal conductivity of aluminium sheets, compared to steel sheets, make them more difficult and more complicated to be laser formed than that of steel sheets. In this Article, using LF process simulation with the finite element software, effects of several process parameters such as laser power, scan speed, laser beam diameter and sheet thickness on final bending angle are investigated. Numerical results are validated with the same parameter assigned experimental results. This comparison shows a very good accordance between simulation and experimental results. Also, an equation is derived to predict the final bending angle correspond to the variations of mentioned parameters. This is derived by the use of Design of Experiment (DOE) and full factorial approach.

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Laser forming is a flexible forming process that needs no hard tooling or external forces. In this paper, laser forming of cylindrical surfaces with arbitrary radius of curvature is investigated analytically and experimentally. As the laser forming process is a die-less forming process, production of a desired shape from initial blank is very difficult with this process. Because in the laser forming process, there are some variable parameters such as laser power, laser beam diameter, laser scanning speed and dimensions of initial blank that directly affect the final shape of the produced part. Also, in addition to above mentioned parameters, in the laser forming process of a cylindrical surface, a new parameter says number of irradiating lines is added to variable parameters. Therefore complexity of laser forming of a cylindrical surface will be more than a simple laser bending. In this paper, an analytical method for laser forming of cylindrical surfaces with arbitrary radius of curvature is proposed. In the proposed method, with the aim of technical limitations of laser machine such as laser power, laser beam diameter and laser scanning speed, the number of irradiating lines and the distance between neighbor lines are proposed for production cylindrical surfaces with arbitrary radius of curvature. Also, using experimental tests the performance and accuracy of the proposed method are investigated and verified. Analytical and experimental results show that with the proposed analytical method, cylindrical surfaces with any arbitrary radius of curvature can be produced with a very good accuracy.

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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.