淬火介质对7050铝合金组织及性能的影响

Effect of Quenching Medium on Microstructures and Mechanical Properties of Aluminum Alloy 7050

采用光学显微镜(OM)、扫描电子显微镜(SEM)、力学性能测试及断裂韧性试验研究了不同淬火介质(空气、水、Na Cl溶液和20%PAG溶剂)对7050铝合金组织和力学性能的影响。结果表明四种淬火介质中,盐浴淬火工艺下的淬火过后的铝合金板材中的第二相粒子体积分数最小,其时效过后的力学性能最好,其次是淬火介质为水时及淬火介质为20%PAG溶剂。空冷状态下的淬火过后的铝合金板材中的第二相粒子体积分数最大,其时效过后的力学性能最差。

The effect of the quenching medium(air,water,NaCl solution and 20%PAG(Polyaleneglycol))on the microstructures,tensile properties and fracture toughness of 7050 aluminum alloy were investigated by means of optical microscopy(OM),scanning electron microscopy(SEM),tensile test and plane-strain fracture toughness test.Results show that the minimum volume fraction of second phase particles of aluminum alloy plate was obtained under salt bath quenching process.Thus,its mechanical properties were the best after aging treatment.Then,it was followed by water quenching and 20%PAG solvent quenching process.Under air cooling process,the volume fraction of second phase particles of quenched alloy plate was the largest,thus resulting in the poorest mechanical properties of alloy after aging treatment.