Leak tightness of magnetic pulse crimped joints

Abstract

The goal of this master thesis is to realize and investigate leak tightness of joints produced by theelectromagnetic pulse (EMP) crimping process. This way of joining metals has gained more attention lately.With EMP welding, leak tight joints can already be achieved. However, the crimping process has somemajor advantages over EMP welding like the fact that more material combinations are possible and itrequires less energy. To realize the leak tightness, two kinds of sealing materials are used: O-rings andadhesives. The workpieces consist of an aluminium or stainless steel tube which is crimped on a solidaluminium mandrel with circumferential grooves in it. First, some preliminary tests are performed todetermine how much the tubes deform in the grooves. This deformation mainly depends on the appliedcharging voltage and the geometry of the groove. With this information, it is possible to estimate the amountof compression an O-ring would undergo when placed inside this groove. On other workpieces, adhesiveswill be applied. Several test procedures can be conducted on the parts to investigate leak tightness. Theresults of a helium test and a pressure burst test on the first test series conducted at the Walloon researchcentre CEWAC already showed that the use of O-rings can be effective.