在Geeble-1500热模拟机上对7055铝合金进行热压缩试验,基于热压缩试验数据,建立流变应力的反向传播(BP)神经网络预测模型和加工图.结果表明:用人工神经网络能更精确地预测热压缩过程中的流变应力,预测精度明显高于线性经验公式的;通过预测模型可以获得样本数据值范围内的非样本数据变形条件下的流变应力,其预测结果充分反映该合金的高温变形特征;在本实验条件下,7055铝合金在高温变形时存在一个失稳区,即变形温度在实验温度范围内应变速率为0.025 s-1以上的区域;在375～425 ℃的范围内,应变速率小于0.001 s-1的区域,最大功率耗散系数为0.45;EBSD技术分析表明在安全区发生部分动态再结晶.利用加工图确定了热变形时的流变失稳区, 并且获得了试验参数范围内热变形的最佳工艺参数, 其热加工温度为350-430 ℃低应变速率区.
参考文献
| [1] | R. Kaibyshev;T. Sakai;F. Musin .Superplastic behavior of a 7055 aluminum alloy[J].Scripta materialia,2001(12):1373-1380. |
| [2] | MONDAL C;MUKHOPADHYAY A K;RAGHU T .Tensile properties of peak aged 7055 aluminum alloy extrusions[J].Materials Science and Engineering A:Structural Materials Properties Microstructure and Processing,2007,455:673-679. |
| [3] | LI Wenbin,PAN Qinglin,Zou Liang,LIANG Wenjie,HE Yunbin,LIU Junsheng.Effects of minor Sc on the microstructure and mechanical properties of Al-Zn-Mg-Cu-Zr based alloys[J].稀有金属（英文版）,2009(01):102-106. |
| [4] | S.D. Liu;X.M. Zhang;M.A. Chen .Influence of aging on quench sensitivity effect of 7055 aluminum alloy[J].Materials Characterization,2008(1):53-60. |
| [5] | Zhihui Li,Baiqing Xiong,Yongan Zhang,Baohong Zhu,Feng Wang,Hongwei Liu.Ageing behavior of an Al-Zn-Mg-Cu alloy pre-stretched thick plate[J].北京科技大学学报（英文版）,2007(03):246-250. |
| [6] | Kanghua Chen;Hongwei Liu;Zhuo Zhang .The improvement of constituent dissolution and mechanical properties of 7055 aluminum alloy by stepped heat treatments[J].Journal of Materials Processing Technology,2003(1):190-196. |
| [7] | Y. C. Lin;Ming-Song Chen;Jue Zhong .Effect of temperature and strain rate on the compressive deformation behavior of 42CrMo steel[J].Journal of Materials Processing Technology,2008(1/3):308-315. |
| [8] | 鞠泉,李殿国,刘国权.15Cr-25Ni-Fe基合金高温塑性变形行为的加工图[J].金属学报,2006(02):218-224. |
| [9] | 汪凌云,范永革,黄光杰,黄光胜.镁合金AZ31B的高温塑性变形及加工图[J].中国有色金属学报,2004(07):1068-1072. |
| [10] | 沈键 .2091铝锂合金高温塑性变形行为研究[D].中南工业大学,1996. |
| [11] | YAN L M;JIAN S;LI J P;LI Z B .Deformation behavior and microstructure of Al-Zn-Mg-Cu-Zr alloy during hot deformation[J].International Journal of Minerals Metallurgy and Materials,2010,17(01):46-51. |
| [12] | 周开利;康耀红.神经网络模型及其Matlab仿真程序设计[M].北京:清华大学出版社,2005:69-89. |
| [13] | 王春水,彭志方,于洋洋.人工神经网络预测变形高温合金的持久强度[J].金属学报,2003(12):1251-1254. |
| [14] | 王清,吴涛,孙东立.采用RBF网络预测含氢TC4合金的高温流变应力[J].材料科学与工艺,2007(04):507-510,514. |
| [15] | Nho-Kwang Park;Jong-Taek Yeom;Young-Sang Na .Characterization of deformation stability in hot forging of conventional Ti-6Al-4V using processing maps[J].Journal of Materials Processing Technology,2002(0):540-545. |
| [16] | P. S. Robi;U. S. Dixit .Application of neural networks in generating processing map for hot working[J].Journal of Materials Processing Technology,2003(1):289-294. |
| [17] | Prasad YVRK;Rao KP .Processing maps and rate controlling mechanisms of hot deformation of electrolytic tough pitch copper in the temperature range 300-950 degrees C[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2005(1/2):141-150. |
| [18] | Bozzini B.;Cerri E. .Numerical reliability of hot working processing maps[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2002(1/2):344-347. |
| [19] | S.V.S. Narayana Murty;B. Nageswara Rao .On the flow localization concepts in the processing maps of IN718[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,1999(1):159-161. |
| [20] | 曾卫东,周义刚,周军,俞汉清,张学敏,徐斌.加工图理论研究进展[J].稀有金属材料与工程,2006(05):673-677. |
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