The effect of constituent particles on the tear resistance of three 6000-series aluminium alloys

Abstract This paper investigates the tear resistance of three cast and homogenized 6000-series alloys, namely AA6061, AA6063 and AA6110, all in temper T6, by means of Kahn tear tests. Of each alloy one commercial version and one tailor-made version were studied. The tailor-made alloys were designed to have approximately three times higher content of constituent particles by increasing the amount of Fe and Si in the chemical composition. The aim was to study in what way a higher constituent-particle content affects the tear resistance and properties of the alloys. The research showed that the unit initiation and propagation energies measured from the Kahn tear tests are markedly reduced when the constituent-particle content is increased, and that the tear resistance is reduced by a higher fraction than the failure strain of the smooth tensile tests. No major differences in the fracture mode and the fracture mechanisms between the alloys with normal and with high constituent-particle content were revealed by the use of computed tomography scanning or scanning electron microscopy imaging. It was concluded for the alloys studied that the increased content of constituent particles had a significant effect on the tear resistance, while the fracture mode and mechanisms remained the same.