6005铝合金型材等温转变曲线绘制及其应用

检测6005铝合金型材不同等温工艺后的硬度和电导率,绘制了等温转变TTT曲线和TTP曲线。利用XRD,TEM等设备对合金经不同等温处理后的物相和微观组织进行了研究,结果表明:6005铝合金的TTT曲线和TTP曲线的鼻尖温度均为340℃,淬火敏感温度区间为280～420℃;等温过程中过饱和固溶体中分解析出β″相,随等温时间的延长,逐步转变为β’相及β相;6005铝合金在不同温度下进行等温处理的相变动力学方程也不同。6005铝合金的相变动力学及其淬火敏感特性研究结果表明,在制订6005铝合金现场在线挤压淬火工艺时,有必要在淬火敏感区间加大冷却速率,而在低于或高于敏感区间时可适当减小冷却速率,这样型材在获得较高的力学性能同时又能减少合金内部残余应力。

Plotting of Isothermal Transformation Curves of 6005 Aluminum Alloy Profiles and Their Application

The time-temperature-transformation(TTT) and time-temperature-property(TTP) curves of 6005 aluminum alloy were determined by isothermal transformation research.And the microstructure transformation during isothermal treatment was studied by XRD,TEM and Avrami equation.The results show that the sensitive temperature range of 6005 aluminum alloy is 280-420℃ with the nose temperature of 340℃.Microstructure observation indicates that the supersaturated solid solution decomposes and β″precipitates during initial stage of isothermal holding.With the prolonging of isothermal time,β′and β form in the alloy.6005 alloy has different transformation kinetics equations when treated at different isothermal treatment temperatures.According to the results,speeding up the cooling rate in the quench sensitive section to reduce the precipitation of equilibrium phase is meaningful,and at higher and lower temperature,decreasing the cooling rate is helpful to decrease the residual stress.