EFFECTS OF THE FLASHJET~(~R) PAINT REMOVAL PROCESS ON THE FATIGUE PROPERTIES OF Al 7075-T6 AND Al 2024-T3

摘要

Due to increasingly stringent environmental constraints, alternate methods for paint removal of military hardware, such as aircraft, are being investigated and developed. DOD studies have shown that 20% of the hazardous waste produced by DOD are due to paint removal operations. FLASHJET~(~R) is a particularly promising alternative that has been shown to not only give significant reductions in generated hazardous waste, but also reductions in cost and improvements in process control. However, the most important issue for these alternative processes is that there is no degradation of the material, such as mechanical properties in any way. The FLASHJET" process inputs heat into a material through high but short duration energy pulses. In this study, the influence of FLASHJET~(~R) processing on the fatigue behavior of two aluminum alloys; (1) Al 2024-T3 and (2) Al 7075-T6 was determined. No degradation in fatigue behavior based on fatigue lifetimes was observed under the conditions tested, and this is in concurrence with a small number of other studies using similar testing methods. More importantly, it was also shown in the present study that almost half of testing conditions gave statistically significant improvement in fatigue lifetimes, and this may be due to the thermal energy affecting stresses at the crack tip of a fatigue crack while being insufficient in magnitude to degrade the strength-related microstructural features of the alloys.