为研究金属微塑性成形特点,对厚度不同及粗细两种晶粒尺寸的黄铜箔试样进行了单向拉伸和微弯曲实验,并采用经典塑性理论和应变梯度理论对弯曲回弹角进行了预测.粗晶粒板料试样单向拉伸实验表明,CuZn37黄铜的硬化曲线存在一种明显的尺寸效应,即板料厚度越小,屈服强度越高.弯曲回弹实验结果也存在另一种明显的尺寸效应现象,即板料厚度越小,回弹角越大.对这两种尺寸效应产生的原因进行了分析,指出应变梯度硬化对微成形工艺过程有重要影响.
Uniaxial tensile tests and microbending experiments of brass foil specimens are performed to investigate size effects of metal foils in microforming process.The specimens are annealed at two different temperatures to obtain fine and coarse grain structure.In the paper,the springback angle in microbending process is predicted based on the classical plasticity theory and strain gradient theory.In uniaxial tensile tests,the increasing of material strength with decreasing foil thickness is observed,which indicates obvious presence of size effects for CuZn37 brass foils,especially for coarse grain specimens.In microbending experiments,obvious size-dependences of springback angle are observed,in which the springback angle of metal foils is increasing with foil thickness decreasing.The reasons for these size effects are discussed and the strain gradient hardening is important to microforming process.
参考文献
| [1] | U. Engel;R. Eckstein .Microforming-from basic research to its realization[J].Journal of Materials Processing Technology,2002(0):35-44. |
| [2] | 李经天,董湘怀,黄菊花.微细塑性成形研究进展[J].塑性工程学报,2004(04):1-8. |
| [3] | Katsuya Suzuki;Yuhei Matsuki;Koichi Masaki;Masumi Sato;Mitsutoshi Kuroda.Tensile and microbend tests of pure aluminum foils withdifferent thicknesses[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2009:77-82. |
| [4] | Jenn-Terng Gau;Chris Principe;Miao Yu .Springback behavior of brass in micro sheet forming[J].Journal of Materials Processing Technology,2007(1/3):7-10. |
| [5] | 冯秀艳,郭香华,方岱宁,王自强.微薄梁三点弯曲的尺度效应研究[J].力学学报,2007(04):479-485. |
| [6] | 王春举,汪鑫伟,郭斌,单德彬.C2680黄铜箔微弯曲回弹规律研究[J].材料科学与工艺,2009(01):5-7. |
| [7] | N.A. Fleck;J.W. Hutchinson .A reformulation of strain gradient plasticity[J].Journal of the Mechanics and Physics of Solids,2001(10):2245-2271. |
| [8] | Zhu HX;Karlhaloo BL .Size-dependent bending of thin metallic films[J].International Journal of Plasticity,2008(6):991-1007. |
| [9] | Nix WD.;Gao HJ. .Indentation size effects in crystalline materials: A law for strain gradient plasticity[J].Journal of the Mechanics and Physics of Solids,1998(3):411-425. |
| [10] | Abu Al-Rub RK;Voyiadjis GZ .A direct finite element implementation of the gradient-dependent theory[J].International Journal for Numerical Methods in Engineering,2005(4):603-629. |
| [11] | Li, H.;Dong, X.;Shen, Y.;Diehl, A.;Hagenah, H.;Engel, U.;Merklein, M. .Size effect on springback behavior due to plastic strain gradient hardening in microbending process of pure aluminum foils[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2010(16/17):4497-4504. |
| [12] | 郭斌,周健,单德彬,王慧敏.黄铜箔拉伸屈服强度的尺寸效应[J].金属学报,2008(04):419-422. |
| [13] | 于宝义,安振之,齐克敏.铜-钢-铜三层复合板室温轧制成形工艺及结合机制的研究[J].热加工工艺,2001(03):34-36. |
| [14] | A.G. Evans;J.W. Hutchinson .A critical assessment of theories of strain gradient plasticity[J].Acta materialia,2009(5):1675-1688. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%