A DIC-Based Study on Fatigue Damage Evolution in Pre-Corroded Aluminum Alloy 2024-T4

Abstract

This paper investigates the fatigue damage and cracking behavior of aluminum alloy 2024-T4 with different levels of prior corrosion. Damage evolution, crack initiation and propagation were experimentally analyzed by digital image correlation, scanning electron microscopy and damage curves. Prior corrosion is shown to cause accelerated damage accumulation, inducing premature fatigue crack initiation, and affecting crack nucleation location, crack orientation and fracture path. For the pre-corrosion condition, although multiple cracks were observed, only one corrosion-initiated primary crack dominates the failure process, in contrast to the plain fatigue cases, where multiple cracks propagated simultaneously leading to final coalescence and fracture. Based on the experimental observations, a mixed-mode fracture model is proposed and shown to successfully predict fatigue crack growth and failure from the single dominant localized corrosion region.

Effectiveness of Nanotechnology Treatments in Composite Aircraft Applications

“…At present, we can state that the initial cracks were noted to originate from pitting damage at numerous locations, as highlighted also in [20], where a detailed narrative of the entire damage evolution process in corrosion-nucleated fatigue was provided. A similar conclusion was derived in [21], where all the precorroded Al 2024-T4 specimens under investigation fractured from cracks associated with pitting. Results indicated that quantities such as pit surface area and surrounding pit proximity were as important as pit depth in determining when and where a crack would form.…”

“…A significant presence of slip bands could also be noted in all specimens with a general direction of development of the phenomenon orthogonal to the application of the load [20,21].…”

Fracture Behaviour of Aluminium Alloys under Coastal Environmental Conditions: A Review

“…Oxide layers frequently and naturally occur on metals exposed to air conditions [112]. As seen in Figure 11, these layers serve as protective barriers that prevent the metal surface from touching corrosive substances like moisture and salts available in corrosive areas.…”

Suitability of DIC and ESPI optical methods for monitoring fatigue damage development in X10CrMoVNb9-1 power engineering steel

“…However, the high sensitivity to vibration of ESPI setup practically narrows its application to the laboratory scale. On the other hand, the DIC was successfully used to determine the fatigue life of different materials, for example: aluminium alloys [25], nickel-based alloys [26], glass fibre-reinforced polymer composites [27], woven organic matrix composites [28] or even asphalt concrete [29].…”