Johan Andersson

Abstract

This is a literature study at the SIMR Joining Technology Centre (Fogningscentrum) with the objective to gather information about the most recent developments in magnetic pulse welding, and to evaluate magnetic pulse welding in terms of technology, economy and environmental effects.

Magnetic pulse welding (MPW) is a cold welding process that is accomplished by a magnetic pulse causing a high-velocity impact between two materials, resulting in a true metallurgical bond. The technology is not a recent development; magnetic pulse welding has been around for about 40 years at date. But new developments of inductors and switches raise the commercial implementations of the process. Engineers are discovering a variety of applications for this solid-state, cold-welding process.

The term “welding" in MPW is somewhat misleading; the technology is suitable for a variety of applications, such as crimping, forming, cutting and perforating and is therefore better referred to as a magnetic pulse technology.

In this literature review, applications of the process, control of the welding parameters and suitable testing procedures are discussed. The advantages and disadvantages for the method are commented together with a comparison to other welding processes.

To date the common applications of magnetic pulse welding have been joining of outer tubular components onto inner tubular components. Further developments of the inductors are, however, continuously increasing the methods applications that might come into practical implementations in a near future. Still, the tubular implementations remain as the most important practical application. One of the strong advantages of magnetic pulse technology is the ability to join dissimilar materials, allowing optimisation of the strengthat minimum weight, e.g. using steel and aluminium, and corrosion protective coatings. Perhaps the most important disadvantage is the lack of flexibility on differing geometries, and the possible hazardous high magnetic fields. For large manufacturing series it is mostly the power of the power source that determines what applications the equipment can be adapted to. However, for mass-production, magnetic pulse technology could be an advantageous method with higher productivity, better process tolerances, high quality weldments and high repeatability.