温热条件对7B04铝合金性能的影响

Effect of Thermal Conditions on Properties of 7B04 Aluminum Alloy

针对高强铝合金航空复杂构件室温成形难问题,通过电阻炉加热及冲压成形试验探究了温热条件对7B04铝合金硬度及成形性能的影响规律,通过差示扫描量热仪及透射电镜探讨其性能变化机理。研究结果表明:7B04铝合金加热后,升温速率越快,材料硬度下降越快;在400℃以上炉温条件下加热较长时间,硬度会先降后升;在200~450℃温度范围内,7B04板材冲压成形性能随出炉温度提高而提高,加热至400℃以上出炉冲压成形效果较好,升温速率的提高可以使7B04铝合金在硬度降幅相同的情况下,达到更高的成形温度,获得更好的成形性能。

To address the forming difficulty of high-strength aluminum alloy aviation complex components,the effect of thermal conditions on the hardness and formability of 7B04 aluminum alloy was explored through resistance furnace heating and stamping and forming experiments.The mechanism was investigated using differential scanning calorimetry(DSC)and transmission electron microscopy(TEM).The results showed that:the faster the heating rate,the faster the hardness of 7B04 aluminum alloy decreases;when heating at the furnace temperature 400~600℃,within several minutes,the hardness first decreased and then increased;in the range of 200~450℃of material temperature,the formability of 7B04 aluminum alloy improved with the increasing temperature;when the material temperature reached 400~450℃,the 7B04 aluminum alloy had the best forming effect.Therefore,a faster heating rate can make the 7B04 aluminum alloy reach a higher forming temperature with the same hardness drop,achieving better formability.