摘要
研究了微量Sc,Zr对Al-Zn-Mg-Cu合金组织性能的影响。结果表明:单独添加0.18%Zr,合金抗拉强度和延伸率明显低于单独添加0.18%Sc,但再结晶抑制效果优于单独添加0.18%Sc。复合添加Sc,Zr较单独添加Sc或Zr具有更好的晶粒细化作用,较强的固溶强化作用和再结晶抑制效果。在Zr含量一定的条件下,合金强度和延伸率随Sc添加量增加而提高。强度和延伸率增加与所析出的LI2结构的Al3Sc,Al3(Sc,Zr)粒子钉扎位错和亚结构,析出粒子数量增加、弥散度增大、分布均匀性提高、析出的η′相所占的体积分数增加有关。当Sc,Zr复合添加量达到0.50%Sc+0.18%Zr时,合金经固溶处理后发生部分再结晶,抗拉强度和延伸率大大降低。合金强度和延伸率降低与晶内、晶界大量析出粗大难熔的DO23结构的Al3(Sc,Zr)粒子有关。
Effects of minor contents of Sc and Zr on the microstructure and mechanical properties of Al-Zn- Mg-Cu alloy were studied. The results show that under respective addition condition the tensile strength and elongation of the alloy with 0.18%Zr were obviously lower but inhibiting recrystallization was better compared to the alloy with 0.18%Sc. Grain refinement effect was much better, and solution strength, recrystallization inhibiting effect were much stronger for the alloy with joint additions of Sc, Zr. At the same content of Zr, the strength and elongation of the alloy increased with increase of Sc addition. Increasing of the strength and elongation of the alloy was related to the following factors, e.g. the pinned dislocations, the substructures of precipitated Al3Sc, Al3（Sc, Zr） particles with the structure of LI2, the increment of the amount precipitated particles, the dispersity, the distribution uniformity, and the volume fraction of the η＇ phase of the precipitated particles. When the content of Sc and Zr was up to 0.50% Sc＋0.18%Zr, it was found that the tensile strength and elongation declined greatly for the alloy after solid solution treatment. The decline of the alloy strength and elongation was related to coarse and high melting point Al3（Sc, Zr） particles with DO23 structure which were precipitated largely in the intracrystalline and at grain boundary.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第4期665-670,共6页
Rare Metal Materials and Engineering
基金
国家重大基础研究项目(2005CB623706)
