Effects of surface profiles on the joint formation during magnetic pulse crimping in tube-to-rod configuration

Abstract

Magnetic pulse crimping is a solid state, high-speed impact crimping technique. In this paper, copper tube was successfully crimped on the steel 1020 rod. Three types of profiles threaded, knurled, and plain profile were created on the steel rod and then a copper tube was crimped on the rod. The influence of surface profiles on the joint strength, surface roughness and microstructure of the joint were analyzed and compared. Compression-shear tests as well as pull-out tests were carried out to compare the strength of the crimped joint. The result of the pull-out tests as well as compression-shear tests revealed that threaded surface profile on the steel rod gives better strength in comparison to the other two profiles. Along the circumference of the Cu-steel composite rod the microstructure images of the joints were taken and analyzed, it was found that there was no gap along the circumference of the sample crimped at 5.3 kJ of discharge energy with plain profile. For surface roughness, the Ra values of the crimped samples at 5.3 kJ were analyzed and it was found that average Ra value of the sample crimped on the threaded base was highest (0.80 μm) among threaded, knurled, and plain base samples.