| In this study, tensile tests were carried out at room temperature to evaluate the influence of δ precipitates on serration behavior of 2090 Al-Li alloy by using reversion heat treatment for the first time. The heat treatment conditions include solution heat treatment, aging and reversion heat treatment. Three different initial strain rates. 2×10^(-3)/sec, 2×10^(-4)/sec and 5×10^(-5)/sec, were used as experimental variables. For all heat treatment conditions, the serration amplitude increased, but the critical strain for the onset of serration decreased with decreasing strain rate. The aged specimen showed the highest serration amplitude and the lowest critical strain for the onset of serration at a given strain rate. The reversion heat treatment after aging decreased the serration amplitude and increased the critical strain for the onset of serration. The results indicate that serration behavior of 2090 Al-Li alloy is affected by work softening due to shearing of δ precipitates as well as by Portevin-Le Chatelier effect caused by the solute atoms. |
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