Selected properties of porous layers formed during the microwelding resistive-pulse process

Presented was the way of forming a porous surface layer on steel with microwelding resistive-pulse using a device WS7000S. Porous properties of the resulting layer were characterized. Mechanical properties were studied and the microstructure was observed.

Groove design for form fit joints made by electromagnetic pulse crimping

The electromagnetic pulse process can be an alternative for many conventional productionprocesses. It can be used for perforating, cutting, welding, forming and crimping. In this thesis, the latter willbe investigated in detail, with the emphasis on tubular joints bearing axial tension and/or torsion loading.To get acquainted with the subject, first a literature study was performed concerning the general principlesof electromagnetic pulse crimping. Because a new field shaper had to be designed, literature on this topicwas also consulted. Finally, the design and use of grooves in crimp joints was studied. It has been reportedthat an inner piece (mandrel) with additional grooves in the joining zone significantly increases the strengthof a crimped joint [1]. However, the information on electromagnetic pulse crimping with a mandrel with morethan one groove is very limited. Therefore one of the main goals of this thesis is to determine an optimaldesign for a mandrel with two grooves used for axially loaded joints. A combination of finite elementsimulations and experiments was used to draw preliminary conclusions involving the double groove design.In a later stage torsional joints will be designed and suitable filler materials to realize leak proof joints will beevaluated.