Influence of RRA on Fatigue Behavior of Al 7075 Alloy

Abstract

In this exercise, I submitted an AL 7075 alloy to a two-step heat treatment procedure known as RRA to look at fatigue behaviour. This procedure combines annealing, high-temperature pre-precipitation, artificial ageing (T6), retrogression, and re-aging, among other heat treatments. The samples are heated to 473o first, then quenched in water medium. The samples are heated further to 18 hours, 22 hours, and 26 hours, respectively. After this, the specimens are heated to 230°, 250°, 270°, and 290° for various lengths of time—7 & 14 minutes, respectively—to increase the material's strength. This process is known as retrogression and re-aging. Following this trial discovered that the RRA approach allows us to maximise the material's strength.