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采用Gleeble-1500热模拟试验机在变形温度为573-723K,应变速率为0.005—0.05 s~(-1),最大变形量为30%的条件下对喷射成形Al-22Si-5Fe合金进行热模拟实验,同时利用OM和XRD对其组织稳定性进行了研究.结果表明,过共晶Al-22Si-5Fe合金的热变形行为同样可用包含Zener-Hollomon参数的模型来处理;低温变形时,沉积合金的变形激活能与纯Al的自扩散激活能一致,较高温度下的变形激活能明显高于纯Al的自扩散激活能,说明沉积合金中大量的第二相对变形会产生显著的影响;较低温加热时,沉积合金中的Si颗粒变化不明显,当加热温度在698 K或以上温度时,过共晶Al-22Si-5Fe沉积合金中的Si颗粒将明显长大;在整个实验温度范围内,富Fe的金属间化合物颗粒几乎未发生变化.
The Gleeble-1500 thermal simulator was used to simulate the spray forming of Al-22Si-5Fe alloy under the conditions of deformation temperature of 573-723K, strain rate of 0.005-0.05 s ~ (-1) and maximum deformation of 30% The results show that the thermal deformation behavior of the hypereutectic Al-22Si-5Fe alloy can also be treated by the model containing the Zener-Hollomon parameter. When the temperature is low, the thermal stability of the deposited alloy The deformation activation energy is consistent with the self-diffusion activation energy of pure Al. The deformation activation energy at higher temperature is obviously higher than that of pure Al, which indicates that a large amount of second relative deformation in the deposited alloy will have a significant effect. During the low temperature heating, the Si particles in the deposited alloy did not change obviously. When the heating temperature was 698 K or above, the Si particles in the hypereutectic Al-22Si-5Fe deposited alloy would obviously grow up. During the whole experimental temperature range , Fe-rich intermetallic compound particles hardly changed.