預(yù)拉伸對2124鋁合金蠕變時效形性同步的影響預(yù)拉伸對2124鋁合金蠕變時效形性同步的影響Effect of pre-stretching on synchronization of shape and property in creep age forming of 2124 aluminum alloy 基于四點(diǎn)彎曲變形裝置，采用光學(xué)金相顯微鏡(OM)、透射電子顯微鏡(TEM)等顯微表征技術(shù)，結(jié)合回彈率和室溫力學(xué)性能測試，研究預(yù)拉伸量對2124鋁合金蠕變時效成形中回彈與性能同步的影響。結(jié)果表明：蠕變時效成形條件下的預(yù)拉伸量適用范圍與人工時效不同，選擇恰當(dāng)?shù)念A(yù)拉伸量可實(shí)現(xiàn)蠕變時效成形過程中成形目標(biāo)與材料性能的耦合調(diào)控。隨著預(yù)拉伸量的增加，彎曲板材試樣蠕變時效后的回彈率先快速下降后緩慢回升，且在預(yù)拉伸3%處，出現(xiàn)回彈最小值；合金的強(qiáng)度呈現(xiàn)出“雙峰形”的增長特征，分別在預(yù)拉伸2%和5%處達(dá)到峰值，在預(yù)拉伸3%處，出現(xiàn)極小值；綜合考慮2124鋁合金板材蠕變成形后的強(qiáng)度、塑性和回彈等條件，推薦的預(yù)拉伸量范圍為1.5%~2.5%。 Based on a four-point-bend forming tools, the effect of pre-stretching on the synchronization of springback and mechanical property in creep age forming of 2124 aluminum alloy was investigated by optical microscopy (OM), transmission electron microscopy (TEM), and tests of springback and mechanical property. The results show that choosing a proper pre-deformation can achieve coupling control of the forming target and the material property in creep age forming process. As the pre-stretching degree increasing, the springback decreases firstly, reaches the minimum value at the pre-stretching degree of 3%, and then rises again slowly. And the strength property curves of the 2124 aluminum alloy present a bimodal variation characteristic, the corresponding pre-stretching at the two peak points are 2% and 5%, respectively, and the minimum point exists at pre-streching of 3%. With comprehensive consideration of the mechanical property and the springback, the recommendatory pre-stretching range of the creep age forming of 2124 aluminum alloy sheets is 1.5%-2.5%.
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