Product Code: JLA_8_6_285

Authors:
Friedrich Dausinger
Ju¨rgen Rapp
Markus Beck
Frank Faisst
Ru¨diger Hack
Helmut Hu¨gel
Universita¨t Stuttgart, Institut fu¨r Strahlwerkzeuge (IFSW), Pfaffenwaldring 43, D‐70569 Stuttgart, Germany

The increasing demand for lightweight structures has led to a greater industrial use of aluminum alloys. The application of these materials is handicapped by a lack of productivity and reliability in the joining techniques currently available. The laser welding of aluminum is markedly more difficult than for steel. The difficulties to be solved include the threshold for deep penetration welding, the occurrence of material related defects and seam deficiencies such as cavities and blowholes that discourage production engineers from making greater use of lasers. A theoretical analysis reveals the requirements that have to be fulfilled by laser systems in order to obtain process stability. In comparison to steel greater focusability and shorter wavelengths are needed. An intensity distribution leading to a V‐shaped keyhole is also beneficial. The results of this analysis are confirmed by welding results obtained with CO₂ and Nd:YAG lasers. An increase in process stability is observed when a dual beam technique or a shorter wavelength laser is applied. In conclusion, the industrial welding of aluminum alloys with appropriate laser systems is a viable option.