Predicting the <i>J</i> integral fracture toughness of Al 6061 using the small punch test

Abstract

ABSTRACT The 6000 series aluminium alloys (Al–Mg–Si systems) are commonly used as medium‐strength structural materials; in particular, the 6061 (Al–1Mg–0.6Si) alloy is widely utilized as a general‐purpose structural material due to its excellent formability and corrosion‐resisting capabilities. The objective of this study was to obtain a correlation between the small punch (SP) test estimated equivalent fracture strain (ɛ qf ) and fracture toughness ( J 1C ) property for 6061 aluminium, and determine its viability as a non‐destructive fracture toughness test technique for remaining life assessment of in‐service components. Samples of 6061‐T6 aluminium were cut from bulk plate, in both the longitudinal and transverse directions, for the as‐received condition as well as subjected to three different over‐ageing heat‐treatment schedules. A strong linear correlation between valid J 1C and SP estimated biaxial fracture strain ɛ qf is presented for aluminium 6061 at room temperature.