Determination of strength values -TRUMPF relies on ZwickRoell Testing Laboratory

TRUMPF is the global market and technology leader in the field of industrial lasers and laser systems. TRUMPF lasers are used in virtually every industry, primarily for joining, cutting and marking and for surface processing on a wide range of materials. In a current project TRUMPF has been assisted by the ZwickRoell Testing Laboratory in determining the strength values of various joints for the manufacture of patchwork blanks used in automobile body construction.

A key market for TRUMPF laser technology is the automotive industry. Besides offering improved driving characteristics coupled with lower fuel consumption, modern cars must also comply with the requirements of the latest crash-test standards. One factor in achieving this is the use of new materials such as high-tensile steel sections. Thanks to their outstanding mechanical characteristic values with regard to strength and ductility they possess high weight-saving potential, particularly in safety-related components in the passenger compartment.

As well as the safety aspect and reduced vehicle CO2 emissions, particular emphasis is placed on cost optimization in the manufacturing process. This is achieved by optimizing and reducing the number of steps in the manufacturing process, together with a reduction in the number of parts installed and in material thicknesses. With this in mind, TRUMPF is constantly developing and testing new laser systems and, from an application standpoint, is also working intensively on new and improved joints using lasers.

In the present case the strength of various welded joints was tested and verified with the assistance of the ZwickRoell Testing Laboratory. Various laser weld seams and shapes were tested for tensile strength in direct comparison with conventional resistance spot-welded joints. All laser welds in the comparative tests were carried out using remote laser welding, with 22MnB5 manganese steel as test material. In one of the test series surface processing was performed using an ultra-short-pulse laser before joining to obtain an even better cross-section of joining applications. The tests were performed in the ZwickRoell Testing Laboratory with a materials testing machine from the ProLine range. "With the support of the ZwickRoell lab team we were able to satisfy ourselves quickly and reliably regarding the quality and strength of laser-welded joints on high-tensile steels and will channel these results into future developments. In this way we will provide our customers in the automotive industry with a genuine alternative to conventional welding methods," states Daniel Maier, TRUMPF Industry Manager Automotive (Hotforming).