Al-Zn-Mg-Cu合金组织与性能的影响
(中南大学 材料科学与工程学院， 长沙 410083)
摘 要: 采用光学显微镜和透射电镜等分析手段研究了复合添加微量Cr、 Mn、 Ti、 Zr对Al-Zn-Mg-Cu合金板材组织性能的影响。 结果表明： 复合添加微量Cr、 Mn、 Ti、 Zr的Al-Zn-Mg-Cu合金具有最佳的再结晶抑制作用。 添加0.04%Ti+0.18%Zr、 0.20%Cr+0.20%Mn+0.04%Ti、0.04%Cr+0.05%Mn+0.04%Ti+0.18%Zr、0.20%Cr+0.20%Mn+0.03%Ti+0.17%Zr 4组微量元素， 合金的抗拉强度和延伸率依次提高；强度依次增加与所析出的共格、 半共格析出相种类增加、 弥散度增大、 粒径增粗、 分布均匀性提高、 所占的体积分数增加有关， 合金延伸率增加与晶内形成的微区无析出区均匀变形有关。
关键字: Al-Zn-Mg-Cu合金； 微量元素； 微观组织； 强度； 延伸率
microstructure and mechanical properties of
Al-Zn-Mg-Cu based alloy
（School of Materials Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: The effect of trace elements on the microstructure and testing properties of Al-Zn-Mg-Cu alloys were studied by optical microscopy and transmitting electron microscopy. The results show that with addition of 0.04%Ti+0.18%Zr, 0.20%Cr+0.20%Mn+0.04%Ti, 0.04%Cr+0.05%Mn+0.04% Ti+0.18%Zr, 0.20%Cr+0.20%Mn+0.03%Ti+0.17%Zr, respectively, the strength of the along increases, from 552.8 MPa to 711.3 MPa, and its elongation increases from 5.5% to 13.8%.The increase of the strength is related to the rising of the kinds of the phase which is coherent or semi-coherent to the matrix, the size of the particles, distribution heterogeneous and the percentage of the second phase volume. The increase of the elongation is related to the improvement of the alloy plasticity by precipitate free zone caused by quenching (Q-PFZ).The alloys with addition of Cr, Mn, Ti, Zr have the strongest effect on the recrystallization of the Al-Zn-Mg-Cu alloys.
Key words: Al-Zn-Mg-Cu alloy; trace element; microstructure; strength; elongation
