High power diode laser welding of metal catalytic coverters

Abstract

The requirements set for modern car exhaust purity is ever higher due to this the design of environmentally friendlier car is ever more difficult. The metallic catalytic converter consists of catalytic metal core and outer tube. It has advantages over to the ceramic convertes by the flexibility of the converter design, but suffers from the higher manufacturing cost. This study concentrates on the development of joint between the catalytic core of the converter and the outer tube structure. A comparative study was performed between CO2-, Nd:YAG- and HPDL laser welding in respect of productivity, investment and weld quality. The results reached with each laser were of higher quality than arc welding. However the heat conduction limited welding turned out to be more suitable for welding this application than the keyhole welding mode. With diode laser welding the joining can be performed with the heat conduction mode welding. An analysis of advantages and restrictions was performed for each welding process.