通过单向拉伸试验，研究了新型Al－Li－Cu－Mg合金板材的基本成形性能。针对材料显著的各向异性性能，选取屈服强度、抗拉强度、延伸率以及厚向异性指数等材料性能参数进行对比分析，绘制了7个不同取样方向的单向拉伸曲线，研究了材料各向异性的规律。基于对本构方程、各向异性屈服准则的研究及对比，建立了新型Al－Li－Cu－Mg合金的本构模型，并根据实验曲线计算得到 Hill48、Barlat89屈服准则中的各向异性参数，结合各屈服准则绘制了新型Al－Li－Cu－Mg合金屈服轨迹。对比分析各试件的断口方向，并结合第一、第三强度理论，分析了材料的各向异性。利用SEM观察试样的断口形貌，分析对比试件断口的韧窝特征及带状特征。研究发现：试件的延伸率越大，其韧窝特征越明显；反之，其带状特征越明显。从微观角度印证了Al－Li－Cu－Mg合金板材存在的各向异性。
This study is to investigate the formability of a new generation Al-Li-Cu-Mg alloy sheet through uniaxial tensile tests. The yield strength, tensile strength, elongation rate of seven different orientations of the sheet material were obtained. The tension curves of different orientations were plotted and compared to work out the anisotropic index. The constitutive equation of this new Al-Li-Cu-Mg alloy was established on the basis of the tensile test data. The characteristic parameters in Hill48 and Barlat89 yield criteria were calculated through the experiment curves and the yield locus of this Al-Li-Cu-Mg alloy was also obtained. Then, the characteristics of the anisotropic behavior of this alloy during the forming process were analyzed on the basis of the First Strength Theory and the Third Strength Theory. In the end, the cross section of fractured specimens were observed using Scanning Electron Microscopy ( SEM) and the results indicated that, if the elongation rate increases, the population of dimples increases correspondingly, in the contrary, if the elongation rate decreases, more fracture belt were observed. The different features of the fracture along different orientations confirm the significant anisotropy of the material.
参考文献
| [1] | 尹登峰,郑子樵.铝锂合金研究开发的历史与现状[J].材料导报,2003(02):18-20. |
| [2] | 郑子樵,李劲风,李红英,陈志国,李世晨,谭澄宇.新型铝锂合金的研究进展与应用[C].中国有色金属学会第十四届材料科学与合金加工学术年会论文集,2011:1-9. |
| [3] | 刘兵,彭超群,王日初,王小锋,李婷婷.大飞机用铝合金的研究现状及展望[J].中国有色金属学报,2010(09):1705-1715. |
| [4] | 刘斌,陈铮铮,顾冰芳,陆渝生,姜剑虹.铝锂合金的发展与应用[J].现代机械,2001(04):71-74,39. |
| [5] | Chen, J.;Madi, Y.;Morgeneyer, T.F.;Besson, J. .Plastic flow and ductile rupture of a 2198 Al-Cu-Li aluminum alloy[J].Computational Materials Science,2011(4):1365-1371. |
| [6] | 杨守杰,陆政,苏彬,戴圣龙,刘伯操,颜鸣皋.铝锂合金研究进展[J].材料工程,2001(05):44-47. |
| [7] | 张澐龙 .铝锂合金机身壁板结构激光焊接特性研究[D].哈尔滨工业大学,2013. |
| [8] | CHEN J Q .Ductile tearing of AA2198 aluminum-lithium sheets for aeronautic application[R].InParis Institute of Technology,Paris,2011. |
| [9] | LSTC.LS-DYNA970 Keyword User′s Manual[M].Liv-ermore:Livermore Software Technology Corporation,2003 |
| [10] | HILL R.The Mathematical Theory of Plasticity[M].Oxford:Clarendon Press,1950 |
| [11] | BARLAT F;LIAN J .Plastic behavior and stretchabili-ty of sheet metals.Part I:A yield function for orthotro-pic sheets under plane stress conditions[J].Interna-tional Journal of Plasticity,1989,5(1):51-66. |
| [12] | Barlat F.;Brem JC.;Yoon JW.;Chung K.;Dick RE.;Lege DJ.;Pourgoghrat F.;Choi SH.;Chu E. .Plane stress yield function for aluminum alloy sheets - part 1: theory[J].International Journal of Plasticity,2003(9):1297-1319. |
| [13] | GB/T 228-2002.金属材料室温拉伸试验方法[S].中华人民共和国国家质量监督检验检疫总局,2002. |
| [14] | GB/T 5027-1999.金属薄板和薄带塑性应变比(r值)试验方法[S]. |
| [15] | GB/T 5028-1999.金属薄板和薄带拉伸应变硬化指(n值)试验方法[S]. |
| [16] | BODILY B;HEINIMANN M;BRAY G et al.Advanced aluminum and aluminum-Lithium solutions for derivative and next generation aerospace structures[R].,2012. |
| [17] | 材料力学[S]. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%