|
|
|
| Effect of Li on Microstructures and Properties of Al-3.5Cu-1.5Mg Alloy |
| YANG Jin-long1,2, LI Si-yu1,2, YE Ling-ying1,2, DENG Yun-lai1,2 |
1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Materials Science and Engineering (Ministry of Education), Central South University, Changsha 410012, China |
|
|
|
|
Abstract The effect of Li on microstructures and properties of Al-3.5Cu-1.5Mg alloy was studied by optical microscopy(OM),transmission electron microscopy(TEM),scanning electron microscopy (SEM),Vickers hardness(HV)and electronic tensile test respectively. The results show that the addition of 1% Li (mass fraction) translates the main precipitation phase S'(Al2CuMg) to S' (Al2CuMg) + δ'(Al3Li) in the alloy, which Cu/Mg atom ratio is about 1. Precipitate free zones (PFZs) are narrowed. Elastic modulus increases by 8GPa. The tensile strength is improved by 21MPa. However, the elongation of the alloy decreases from 20.3% to 15.8%. The form of fracture morphology is changed from ductile fracture to ductile/brittle mixed fracture.
|
|
Received: 12 November 2012
Published: 20 May 2013
|
|
|
|
|
|
| [1] POLMEAR I J. Light Alloys: Metallurgy of the Light Metals[M]. New York: John Wiley & Sons,1995.[2] JAMES C W, EDGAR A S Jr. Progress in structural materials for aerospace systems[J].Acta Materialia,2003,51(19):5775-5799.[3] SHA G, MARCEAU R K W, GAO X,et al. Nanostructure of aluminium alloy 2024: segregation, clustering and precipitation processes[J].Acta Materialia,2011,59(4):1659-1670.[4] WANG S C, STARINK M J, GAO N. Precipitation hardening in Al-Cu-Mg alloys revisited[J]. Script Materalia,2006,54(2):287-291.[5] STARINK M J, GAO N, KAMP N,et al. Relations between microstructure, precipitation, age-formability and damage tolerance of Al-Cu-Mg-Li (Mn,Zr,Sc) alloys for age forming[J]. Materials Science and Engineering A,2006,418(1):241-249.[6] BANERJEE S, ROBI P S,SRINIVASAN A,et al. Effect of trace additions of Sn on microstructure and mechanical properties of Al-Cu-Mg alloys [J].Materials and Design, 2010,31(8):4007-4015.[7] BAKAVORS D,PRANGNELL P B, BES B, et al.The effect of silver on microstructural evolution in two 2xxx series Al-alloys with a high Cu:Mg ratio during ageing to a T8 temper[J].Materials Science and Engineering A,2008,491(1):214-223.[8] LAVERNIA E J,GRANT N J. Review aluminium-lithium alloys [J].Journal of Materials Science,1987,22(5):1521-1529.[9] HUANG B P, ZHENG Z Q. Precipitation kinetics of an Al-4.01Cu-1.11Li-0.39Mg-0.19Zr-0.11Ti alloy[J].Scripta Materialia,1998,38(4):611-616.[10] MA Y, ZHOU X, THOMPSON G E, et al. Distribution of intermetallics in an AA 2099-T8 aluminium alloy extrusion [J]. Materials Chemistry and Physics,2011,126(1):46-53.[11] LEQUEN Ph,SMITH K P, DANIELOU A. Aluminum-copper-lithium alloy 2050 developedfor medium to thick plate[J]. Journal of Materials Engineering and Performance,2010,19(6):841-847.[12] KOVARIK L, COURT S A,FRASER H L,et al. GPB zones and composite GPB/GPBII zones in Al-Cu-Mg alloys[J].Acta Materialia,2008,56(17):4804-4815.[13] HUANG B P, ZHENG Z Q. Independent and combine roles of trace Mg and Ag additions in properties precipitation process and precipitation kinetics of Al-Cu-Li-(Mg)-(Ag)-Zr -Ti alloys[J]. Acta Metallurgica, 1998,46(12):4381-4393.[14] ZHU A W, STRAKE E A. Strengthening effect of unshearable particles of finite site:a computer experimental study[J]. Acta Materialia,1999,47(11):3263-3269.[15] 赵建华,陈泽宇,李思宇,等.2124铝合金蠕变时效行为与力学性能的影响[J].材料工程,2012,(10):67-72. ZHAO Jian-hua, CHEN Ze-yu, LI Si-yu, et al. Effect of initial state on creep aging behavior and mechanical properties of 2124 aluminum alloy [J]. Journal of Materials Engineering, 2012,(10):67-72.[16] GANDIN CH A, JACOT A. Modeling of precipitate-free zone formed upon homogenization in a multi-component alloy[J]. Acta Materialia,2007,55(7):2539-2553.[17] STARINK M J. Reduced fracturing of inter metallic particles during crack propagation in age hardening Al-based alloys due to PFZs[J]. Materials Science and Engineering A,2005,390(1-2):260-264. |
|
|
|
2013, Vol. 0 
