Improving the quality of Al-Fe tube joints manufactured via magnetic pulse welding using an inclined-wall field shaper

Abstract

Due to the mismatched impact parameters between the velocity and the angle, a joint with an unbonded zone in the middle and the microdefects at the interface was fabricated by magnetic pulse welding (MPW). In this study, an oblique angle in the working zone was prefabricated to make an inclined-wall field shaper (FS) for MPW and thereby improve the quality of the joint. The effects of the span and size of the inclined wall on the impact parameters were evaluated by numerical simulations. With increasing span, the location where the maximum impact velocity occurred approached the free end of the joint. With increasing size of angle, the initial impact angle evidently increased. The microstructure indicated that the flat interface was changed into the wavy one, and the thick transition layer with microdefects could be removed using an inclined-wall FS. The double bonding zone was changed into the single one, which formed a continuous range with a length of above 3 mm where the impact parameters matched with each other. The length of the unbonded zone in the initial collision zone decreased from about 1 mm to 0.3 mm via using an inclined-wall FS with the span of 6.4 mm and the size of 5°. Shear test results showed that the zones with high strength were merged in the initial collision region. The maximum shear strength of about 81 MPa could be obtained using an inclined-wall FS with the size of 3° and the span of 6.4 mm, which was increased by 33% higher than that without an inclined wall.