(中國航空工業(yè)集團公司 北京航空材料研究院，北京100095)
摘 要: 采用室溫拉伸力學(xué)性能測試和透射電鏡觀察等研究熱暴露對7A12-T7352自由鍛件微觀組織和力學(xué)性能的影響。結(jié)果表明，熱暴露溫度顯著影響合金的力學(xué)性能；當熱暴露溫度不高于125 ℃時，合金的強度略有且升高，且可以在較長時間內(nèi)保持穩(wěn)定；當熱暴露溫度高于150 ℃時，合金的強度隨著熱暴露時間的延長持續(xù)下降，熱暴露溫度越高，強度下降幅度越大。在高于150 ℃熱暴露過程中，h′相和h相的快速粗化是導(dǎo)致7A12自由鍛件強度下降的內(nèi)在原因。
關(guān)鍵字: 7A12鋁合金；熱暴露；微觀組織；力學(xué)性能
（Beijing Institute of Aeronautical Materials, Aviation Industry Corporation of China, Beijing 100095, China）
Abstract:The microstructure and mechanical properties of 7A12-T7352 forging under different thermal exposure conditions were studied by TEM analysis and tensile test. The results show that thermal exposure temperature affects the mechanical properties of the forging significantly. When the alloy is exposed at 125 ℃ or lower, the strength will increase and then keep stable for a long time. When the thermal exposure temperature is higher than 150 ℃, the strength decreases obviously with increasing the thermal exposure time. Higher exposure temperature leads to greater decrease of the strength. The strength decreases due to the coarsening of h′ and h phases when the alloy exposed at temperature higher than 150 ℃.
Key words: 7A12 Al alloy; thermal exposure; microstructure; mechanical property
