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采用光学显微镜(OM)、扫描电镜(SEM)和透射电镜(TEM)等研究了在70 MPa的拉应力下90、120和150℃时Sc微合金化对8xxx系铝合金导线的蠕变性能及其组织形貌的影响。结果表明:在蠕变试验中,Al-0.7Fe-0.2Sc合金的稳态蠕变速率在90~150℃/70 MPa范围内为1.203×10~(-8)s~(-1)~4.346×10~(-7)s~(-1),在150℃/70 MPa下,Al-0.7Fe的稳态蠕变速率为2.027×10~(-6)s~(-1),是Al-0.5Fe-0.2Sc合金的4.6倍。Sc的添加能抑制Al_3Fe相的形核及析出。另外,在70 MPa时,低温蠕变下,Al_3Fe和Al_3Sc相的形状和尺寸没有显着变化。TEM图像显示Al_3Fe相不均匀地分布在亚晶界而不是内部晶粒中,位错环由Al_3Sc沉淀相钉扎,阻碍位错移动。
The effects of Sc microalloying on the creep properties of 8xxx series aluminum alloy wires at 90, 120 and 150 ℃ under tensile stress of 70 MPa were investigated by optical microscope (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) The effect of its morphology. The results show that the steady creep rate of Al-0.7Fe-0.2Sc alloy in the creep test is 1.203 × 10 -8 -8 s -1 (4.346) in the range of 90-150 ℃ / 70 MPa × 10 ~ (-7) s ~ (-1). The steady state creep rate of Al-0.7Fe is 2.027 × 10 ~ (-6) s ~ (-1) at 150 ℃ / -0.5Fe-0.2Sc alloy 4.6 times. The addition of Sc can inhibit the nucleation and precipitation of Al 3 Fe phase. In addition, at 70 MPa, the shape and size of the Al 3 Fe and Al 3 Sc phases did not change significantly at low temperature creep. The TEM images show that the Al 3 Fe phase is distributed unevenly in the subgrains instead of the internal grains. The dislocation loops are pinned by the Al 3 Sc precipitation and impede the dislocation movement.