Overview of aluminum alloy mechanical properties during and after fires

Abstract

Aluminum alloys are increasingly being used in a broad spectrum of load-bearing applications such as lightweight structures, light rail, bridge decks, marine crafts, and offshore platforms. A major concern in the design of land-based and marine aluminum structures is fire safety, at least in part due to mechanical property reduction at temperatures significantly lower than that for steel. A substantial concern also exists regarding the integrity and stability of an aluminum structure following a fire; however, little research has been reported on this topic. This paper provides a broad overview of the mechanical behavior of aluminum alloys both during and following fire. The two aluminum alloys discussed in this work, 5083-H116 and 6061-T651, were selected due to their prevalence as lightweight structural alloys and their differing strengthening mechanisms (5083strain hardened, 6061precipitation hardened). The high temperature quasi-static mechanical and creep behavior are discussed. A creep model is presented to predict the secondary and tertiary creep strains followed by creep rupture. The residual mechanical behavior following fire (with and without applied stress) is elucidated in terms of the governing kinetically-dependent microstructural mechanisms. A review is provided on modeling techniques for residual mechanical behavior following fire including empirical relations, physically-based constitutive models, and finite element implementations. The principal objective is to provide a comprehensive description of select aluminum alloys, 5083-H116 and 6061-T651, to aid design and analysis of aluminum structures during and after fire.

Revealing the Effect of Local Connectivity of Rigid Phases during Deformation at High Temperature of Cast AlSi12Cu4Ni(2,3)Mg Alloys

“…E m can be approximated to the Young’s Modulus of AA6061 at 300 °C (0.66 wt.% Si, 0.9 wt.% Mg, 0.24 wt.% Cu) [41]:${\mathrm{normalE}}_{\mathrm{normalm}}=50 \mathrm{GPa},$…”

Effect of Pulse Duration on Corrosion and Impression Creep Properties of AA5083‐H111 Al–Mg Alloy Weldments Processed by P‐GTAW

“…It is apparently visible that after a short primary creep stage almost all the curves exhibited an extended secondary‐creep region where depth increased linearly with time. It is not possible to record the tertiary stage of the curve since the impression creep test is compressive in nature, necking and fracture of the specimen do not occur . The Figure a and b showing that at ambient temperature (303 K), no significant difference was observed in impression velocity and steady‐state creep rate and thus, showed the similar value of impression depth (approx.…”

“…The creep resistance of weldments can be determined by obtaining thermal activation parameters, aiding the identification of the rate controlling mechanisms of creep. According to the literature, the creep resistance of any surface is directly related to its hardness. Generally, the hardness of AA5083 alloy weldment is on the lower side due to the loss of strain hardening effects during fusion welding.…”

Seismic Analysis of Low and High Rise Building Frames Incorporating Metallic Yielding Dampers

“…The shear yielding of aluminium had been found to be very ductile and very large inelastic deformations are possible without tearing or buckling [7]. The low yield strength of aluminium in shear allows the use of thicker webs which further reduces the chances of web buckling.…”