探讨了添加微量Ag对高Zn超高强Al-Zn-Mg-Cu合金微观组织和力学性能的影响.采用力学拉伸实验、能谱分析、扫描电镜和透射电镜等手段对不同热处理方式的合金进行了分析.结果表明:向合金中添加微量Ag会促进粗大相的形成,消耗合金元素Zn、Mg,对合金力学性能不利.在采用相同的固溶时效工艺时,加Ag合金的抗拉强度降低了近40 MPa.但另一方面,Ag可以提高合金的固溶处理温度,使残留的粗大相在更高的固溶温度下较充分固溶,降低Ag对合金力学性能的不利影响.采用高温固溶处理后,加Ag合金T6态抗拉强度与不加Ag合金相当,但塑性有所下降.在时效过程中,微量Ag会促进过渡相的形成,并提高GP区和过渡相的稳定性,但使合金到达峰值的时间延长.
参考文献
| [1] | Lee S M .A critical evaluation of the stress-corrosion cracking mechanism in high-strength aluminum alloys[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1991,22(10):2407-2414. |
| [2] | 刘继华,李荻,郭宝兰.7xxx系列Al合金应力腐蚀开裂的研究[J].腐蚀科学与防护技术,2001(04):218-222. |
| [3] | NAJJAR D .Influence of critical surface defects and localized competition between anodic dissolution and hydrogen effects during stress corrosion cracking of a 7050aluminum alloy[J].Materials Science and Engineering A,1997,A238:293-302. |
| [4] | Sieradzki K .Notes on the surface mobility mechanism of stress-corrosion cracking[J].Corrosion Science,1994,36(04):669-675. |
| [5] | Polmear I J .A trace element effect in alloys based on the aluminum-zinc-magnesium system[J].NATURE,1960,186:303-304. |
| [6] | Baba Y .Ageing phenomena and lattice defects in AlZn and Al-Zn-Mg alloys[J].Transactions of the Japan Institute of Materials,1968,7:224-234. |
| [7] | Maloney S K .The chemistry of precipitates in an aged Al-2.1Zn-1.7Mg at% alloy[J].Scripta Materialia,1999,41:1031-1038. |
| [8] | Maloney S K .The effects of a trace addition of silver upon elevated temperature ageing of an Al-Zn-Mg alloy[J].MICRON,2001,32:741-747. |
| [9] | Lee C W .The effect of silver addition on 7055 Al alloy[J].Materials & Design,1997,18(4/6):327-332. |
| [10] | 田荣璋;王祝堂.铝合金及其加工手册[M].长沙:中南工业大学出版社,1988:16. |
| [11] | Y.V.Milman;A.I.Sirko;D.V.Lotsko .Microstructure and Mechanical Properties of Cast and Wrought Al-Zn-Mg-Cu Alloys Modified with Zr and Sc[J].Materials Science Forum,2002(Pt.2):1217-1222. |
| [12] | 蒙多尔福;王祝堂.铝合金组织与性能[M].北京:冶金工业出版社,1988:564. |
| [13] | Macchi C E .Influence of small addition of Ag on the ageing kinetics of an Al-Zn-Mg alloy: a positron annihilation study[J].Materials Science Forum,2002,396-402:833-838. |
| [14] | ZHANG Kun;LIU Zhi-yi;YE Cheng-wu .Evolution of undissolved phases in high-zinc content super-high strength aluminum alloy during ageing[J].Transactions of Nonferrous Metals Society of China,2004(2):356-361. |
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