Mechanical properties and interface morphology of magnetic pulse-welded Al–Fe tubes with preset geometric features

A dissimilar metal tube joint fabricated by magnetic pulse welding (MPW) usually has uneven mechanical properties and an uneven morphology along the welding direction due to the small discontinuous matching range of the collision parameters. In this work, inclined, concave, and convex wall features were prefabricated on the target tube to improve the uniformity of the mechanical properties. The effects of the types of features and the prefabricated angle on the collision parameters, the axial distribution of the strength, and the interfacial morphology were investigated by simulations, shear tests, and microscopic observations, respectively. The results show that the collision parameters were increased with the increase of the prefabricated angle under the three types of features. Compared with the case without features, the increment of the collision parameters was found to be the greatest under the convex wall feature, and the smallest under the concave wall feature. With the increase of the prefabricated angle under the three types of features, the average shear strength tended to be reduced. When the prefabricated feature was the concave wall with a prefabricated angle of 5°, the quality of the joint was the best; it had an average shear strength of 46.46 MPa, an increase of 87%, and a low standard deviation of 4.96 MPa, a decrease of by 81%, as compared with that without geometric features. The transition layer was found to be the largest under the concave wall feature, and the maximum thickness decreased with the increase of the prefabricated angle.