【摘要】 采用铸锭冶金法制备了含Yb的Al-Zn-Mg-Cu-Zr合金。通过对硬度、电阻率、强度、应力腐蚀性能的测试和用金相显微镜和透射电镜的观察,分析了Yb微合金化对Al-Zn-Mg-Cu-Zr合金再结晶行为和性能的影响。结果表明,在Al-Zn-Mg-Cu-Zr合金中添加微量Yb能形成含Yb的细小弥散相,因此提高T6态合金的再结晶温度,显著提高合金的应力腐蚀抗力和断裂韧性,并略微提高合金的强度和塑性。这些均匀分布于基体上的弥散相能强烈钉扎位错和亚晶界,抑制了再结晶形核,显著抑制了基体再结晶,保持形变回复组织。更多还原

【Abstract】 Al-Zn-Mg-Cu-Zr alloys containing Yb were prepared by cast metallurgy.Effects of 0.30 wt% Yb additions on the recrystallization behavior and the performances of Al-Zn-Mg-Cu-Zr alloys were investigated by hardness and electric resistance measurement,tensile test,stress corrosion cracking test measurement,optical microscopy and transmission electron microscopy.The results show that the ytterbium additions to Al-Zn-Mg-Cu-Zr aluminum alloys will increase the recrystallization temperature,obviously enhance the resistance to stress corrosion cracking and the fracture toughness property,and slightly increase the strengths and ductility at T6 treatment.It is attributed to the dispersoids with Yb containing.Those dispersoids homogeneously distributed in the Al matrix strongly pin dislocation and subgrain boundaries,which can significantly retard the recrystallization by inhibiting the nucleation of recrystallization.更多还原