The effect of beam profile at a focal point on welding deformation. A study of the deformation behaviour by laser welding at micron or submicron level in automobile parts

Due to a growing awareness for the environment, demands for functions which enable cleaner exhaust emissions and lower fuel consumption have increased in the field of automotive components. In order to manufacture automotive components that meet these demands and still remain competitive, it is vital to develop high-precision processing technologies for realising new functions. One technique which has been receiving attention is laser processing.^1,2 Laser welding has a higher energy density and hence induces much less welding deformation than arc welding. However, even this degree of deformation is too significant to ignore in welding at micron and sub-micron levels (which is the subject of this study). Also, since the types of lasers used in laser welding vary greatly, an understanding of the characteristics between laser energy distribution (the beam profile) and welding deformation is necessary to improve precision in processing. For example, by examining the effects of different beam profiles at the focal point on welding deformation, it will be possible to obtain a beam profile and enable the reduction and control of welding deformation at the sub-micron level.