摘要
采用铸锭冶金法制备高Zn(质量分数为10.8%)7075铝合金,用金相显微镜、扫描电镜和能谱等分析了提高Zn含量后7075铝合金显微组织的变化,并研究了不同回归热处理对该合金力学性能的影响。结果表明,Zn质量分数提高到10.8%时,合金晶粒细化,在T6状态下,合金抗拉强度达到650 MPa,屈服强度为620 MPa,较常规7075铝合金分别提高了10.2%和13.8%,但伸长率仅为2.8%;含10.8%Zn的7075铝合金经优化回归热处理(120℃×12 h+190℃×10 min+120℃×16 h)后,抗拉强度为714 MPa,屈服强度为690 MPa,伸长率为8.3%,较T6状态分别提高了9.8%、11.3%及196%。
7075 aluminum alloy containing high Zn（ mass fraction 10. 8%） was prepared by ingot metallurgy method. Effects of adding high Zn content and the retrogression and re-aging treatment on microstructure of the alloy were analyzed by optical microscopy,scanning electron microscopy and spectroscopy,and the mechanical properties were also studied to optimize the heat treatment process. The results show that after adding Zn element,grains of the alloy are greatly refined. Under T6 aging treatment,the tensile strength and yield strength of the alloy are 650 MPa and 620 MPa,respectively,and are enhanced by 10. 2% and 13. 8% compared with these of the 7075 alloy,however the elongation is only 2. 8%. The optimized retrogression and re-aging（ RRA） treatment process is composed of 120 ℃ × 12 h ＋ 190 ℃ × 10 min＋ 120 ℃ × 16 h. Tensile strength,yield strength and elongation of the 7075 alloy after RRA treatment are 727 MPa,703 MPa and 8. 3%,and increased by 11. 8%,11. 3% and 196%,respectively,compared with these of the T6 states.
出处
《金属热处理》
CAS
CSCD
北大核心
2016年第2期11-15,共5页
Heat Treatment of Metals
关键词
7075铝合金
锌
回归热处理
显微组织
力学性能
7075 aluminum alloy
Zn
regression and re-aging（RRA）
microstructure
mechanical properties
