Experimental and numerical simulation of magnetic pulses for joining of dissimilar materials with dissimilar geometry using electromagnetic welding process

Abstract

In this paper the joining of dissimilar metal couple SS-Cu employing the magnetic pulse welding (MPW) technique that deploys magnetic pressure to force the primary metal against the target metal cleansing away contaminants from surface while driving intimate metal-to-metal contact, producing a weld. MPW process is very fast, produces no heat affected zone (HAZ) and may be performed without filler metals and protective gases. Nevertheless, a thin film (10 to 40 μ m) of two welded metals in the form of intermetallic phases were observed, in which melting and solidification processes took place. This paper focuses on the interface for studying the typical wavy pattern and mutual diffusion of elements happening in the zone. The transition zone is composed of elements intermetallics, micro cracks and micro pores. The weld interface composition, structure and morphology were studied by optical and scanning electron microscopy (SEM). Energy-dispersive spectrometry (EDS) was used in order to evaluate the local distribution of alloying elements at the joint interface and its vicinity and also Nano-hardness tests were performed across the bonding zone at regular increments. The results of joints characterization allowed determining the optimal MPW process parameters.