Effect of corrosion on the fatigue life and fracture mechanisms of 6101 aluminum alloy wires for car manufacturing applications

Abstract

An innovative solution for the automotive industry is to replace the copper used for wiring harnesses with aluminum alloys, such as the aluminum-magnesium-silicon 6101 alloy. Wiring harnesses are composed of thin strand arms obtained by a wire drawing process. These strands are susceptible to exposure to a corrosive environment and fatigue solicitations simultaneously. The fatigue endurance of this alloy was studied using the stress-life approach for three metallurgical states representative of three colddrawing steps. Fatigue tests performed in corrosive media tests highlighted a strong decrease of the 6101 alloy lifetime due to fatigue-corrosion interactions and a modification of failure modes.

Effect of new sealing treatments on corrosion fatigue lifetime of anodized 2024 aluminium alloy

“…Finally, this damage of the hydrothermally sealed anodic film enhanced probably the fast apparition of pits, sufficiently wide to induce crack initiation. This fast crack initiation during the first minutes of immersion under corrosion fatigue was already seen in previous works [32,33]. Moreover, Shahzad and coworkers have revealed for AA 2214 T6 the presence of cavity like defects and crazing in the sealed (in nickel-acetate solution at 98°C for 20 min) anodic film, promoting fatigue crack initiation [17].…”

Observations on the damage behaviors of corrosion fatigue in steel strands based on image analysis

“…This decrease accelerates the crack formation and expansion in the steel wires. For the corrosion fatigue in particular, 24,25 the actions of the alternating stress will catalyze the corrosive processes. The corrosive actions of the media will further exacerbate the expansion of the fatigue cracks.…”

Influence of equal-channel angular pressing on the corrosion fatigue behaviour of an Al-Mg-Si aluminium alloy for automotive conductors

“…On the contrary, very few works focused on the influence of SPD on the corrosion fatigue behaviour of Al-Mg-Si alloys, where multiple works about conventionally processed alloys have shown a decrease in fatigue lifetime due to premature crack initiation on corrosion defects [15][16][17][18][19][20]. The plastic deformation localisation around the corrosion defects and hydrogen embrittlement at defect/crack tip are the common mechanisms mentioned to explain this decrease in fatigue lifetime under corrosion fatigue conditions [21,22].…”

“…As stated above, the influence of SPD, and in particular ECAP, on such mechanisms is still not well documented at this time. Laurino et al studied the corrosion fatigue behaviour and fracture mechanisms of an AA6101-T9 obtained by a two-step cold drawing process [15]. In the T9 metallurgical state, very elongated grains were observed in the wire drawing direction with a 500-nm width in the transverse plane.…”