Environmental Failure Behavior Analysis of 7085 High Strength Aluminum Alloy under High Temperature and High Humidity

Abstract

High-strength aluminum alloys are exposed to more and more environmentally-induced cracking failure behaviors during service. However, due to the hard to detect nature of hydrogen, and the special working conditions, failure research has obvious hysteresis and complexity, and it is impossible to truly reflect the material failure phenomenon and mechanism. In this paper, 7085 high-strength aluminum alloy is selected as the research material to simulate and reproduce the environmental failure phenomenon of aircraft under extreme working conditions (temperature 70 °C, humidity 85%). The results proved that high-strength aluminum alloy has environmental cracking failure behavior under extreme working conditions. The failure mode that was determined was due to environment-induced hydrogen and hydrogen-induced cracking, which is the result of the combined action of hydrogen and stress. Meanwhile, we demonstrate that high-strength aluminum alloy’s environmental failure behavior in an environment of high temperature and high humidity is different from traditional stress corrosion cracking behavior.

Keywords

• 7085 high strength aluminum alloys
• hydrogen
• environmental induced failure
• stress corrosion cracking
• brittleness