a study in crack appearance in 1050 aluminium alloy rivets

1xxx series Aluminium alloys, are widely used in different industries; because of high formability, suitable strength and physical properties. Rivets are one of these Aluminium group products. In some cases and at the last production step, rivet’s head tear from the contact point with forming hand device and causes product failure, waste of material and imposes more cost. micro/macro structure analysis from the defect point indicated different inclusions, concentrated near the crack. scanning electron microscope(SEM) images and energy dispersive spectroscopy(EDS) analysis verified the existence of iron rich inclusions in the crack wall. There was a V shape macro crack observed in billet vertical section, which separated the primary pipe surface and the second melt sloped in that. The film oxide in this interface, elongated during the extrusion process and makes weak and brittle tail in the final rod and decrease the critical stress to form a crack along the film oxide.

Keywords:

1050 aluminium alloy , macro crack , oxide film