In-fire material properties of wire-arc additively manufactured 3D-printed structural aluminum alloys

Abstract

Additive manufacturing, often known as 3D printing, is being increasingly used in the construction sector. This paper reports an experimental investigation on the in-fire material properties of 3D-printed structural aluminum alloys at elevated temperatures. The testing program mainly encompasses 30 in-fire material tests and 6 ambient-temperature material tests on grade 6063 aluminum alloy, which was 3D-printed by means of wire-arc additive manufacturing. Two material thicknesses including 3 mm and 5 mm, and three printing orientations including 0°, 45° and 90°, were considered in the testing program. Six different temperature levels varying from 20 °C to 500 °C were adopted in the material testing, to derive the corresponding material stress–strain responses and key material property retention factors. The retention factors were adopted to analyze the thermal effect on the residual strength and stiffness of wire-arc additively manufactured aluminum alloys at elevated temperatures. The retention factors given in the aluminum fire-design standards in Europe and America were also assessed based on the test data, with design inaccuracy revealed. To overcome this limitation, retention factor predictive models were proposed to accurately predict the in-fire properties of wire-arc additively manufactured aluminum alloys. Then, a new Ramberg–Osgood material constitutive model was proposed, demonstrating a high level of accuracy in predicting the stress–strain behavior of wire-arc additively manufactured aluminum alloys at elevated temperatures.