Environmental-Assisted Fatigue Crack Propagation in 3003-0 Aluminum

Abstract

Brazed aluminum heat exchangers have found wide applications in the production of cryogens. Their use has ranged from very benign service (i.e., inert environment and static pressure) to applications where moist air and its components are encountered over a range of temperatures, +24°C (+75°F) to −101°C (−150°F), along with cyclic pressures. The general performance of the brazed aluminum heat exchangers under these varying conditions has been good. Failures can usually be attributed to fatigue, corrosion, erosion, or static over-pressurization, with fatigue and corrosion the most troublesome, according to service data [¹]. At present, there are no data available on the effect of environment, temperature, frequency, or other conditions on the fatigue life of the 3003-0 aluminum alloy, which is the primary component of brazed aluminum heat exchangers. The purpose of this study was to provide an initial investigation of the effects of test temperature, frequency, and environment on the fatigue crack growth rate in 3003-0 aluminum, so that more intelligent design and applications of 3003-0 aluminum in brazed aluminum heat exchangers will be possible. Initiation phenomena were ignored.