介观尺度磷青铜薄板韧性断裂和变形行为的尺寸效应

摘要/Abstract

摘要： 借助单轴微拉伸试验研究了磷青铜薄板力学性能和韧性断裂的尺寸效应。结果表明，屈服强度与材料厚度t、晶粒尺寸d之间均存在着第Ⅱ类尺寸效应，但与t/d之间却存在着第Ⅰ类尺寸效应。断口形貌显示，随着t的减小，断裂机制由韧窝-微孔聚集断裂向滑移分离过渡；随着d的增大，韧窝逐渐变大变深，但当t/d<1时，拉伸过程过早形成微裂纹，导致试样迅速断裂。最后，基于表面层模型构建了介观尺度磷青铜薄板的混合本构方程。

关键词: 磷青铜, 断口分析；屈服强度, 尺寸效应

Abstract: Size effects of mechanics properties and ductile fractures for ultra thin sheet metal of phosphor bronze sheet were studied by uniaxial micro tensile test. Experimental results show that yield strength has second order size effeets with metal thickness t and grain size d， and has first order size with t/d. Fracture surface shows that the fracture mechanism is composed of transitions from dimple-microvoids accumulation fractures to slip separation with the material thicknesses decrease, and dimple morphology becomes larger and deeper with the increases of grain sizes, but when t/d＜1, initiation of micro cracks is geminated, and fracturs are occurred immediately. At last, a hybrid constitutive equation was established based on surface layer model.

Key words: phosphor bronze, fractography analysis, yield strength, size effect

中图分类号:

王蕾, 胡道春. 介观尺度磷青铜薄板韧性断裂和变形行为的尺寸效应[J]. 中国机械工程.

WANG Lei, HU Daochun. Size Effects of Deformation Behaviour and Ductile Fractures in Meso-scale Thin Sheet Metal of Phosphor Bronze[J]. China Mechanical Engineering.

参考文献

[1]孙军,刘刚,丁向东.介观尺度铜膜力学行为尺度效应研究进展[J].中国材料进展, 2009, 28(1):49-53.
SUN Jun, LIU Gang, DING Xiangdong. Progress in the Size-dependent Mechanical Properties of Cu Films at Mesoscale[J]. Materials China, 2009, 28(1):49-53.
[2]LEOPOLD J. Foundations of Micro Forming[C]// Proceedings of the 6th ICTP. Nuremberg, 1999:889-894.
[3]彭林法,李成锋,来新民,等.介观尺度下的微冲压工艺特点分析[J].塑性工程学报,2007,14(4):54-59.
PENG Linfa, LI Chengfeng, LAI Xinming, et al. Characteristic Analysis of Stamping Process in Miceo/Meso Scale[J]. Journal of Plasticity Engineering, 2007, 14(4):54-59.
[4]FU M W, CHAN W L. Flow-induced Defects in Mesoforming Processes[M]. London:Springer, 2014:131-149.
[5]VOLLERTSEN F, NIEHOFF H S, HU Z. State of the Art in Micro Forming[J]. International Journal of Machine Tools & Manufacture, 2006, 46(11):1172-1179.
[6]HOFFMANN H, HONG S. Tensile Test of Very Thin Sheet Metal and Determination of Flow Stress Considering the Scaling Effect[J]. Annals of the CIRP, 2006, 55(1):417-423.
[7]ENGEL U, ECKSTEIN R. Microforming—from Basic Research to Its Realization[J]. Journal of Materials Processing Technology, 2002, 125/126(2):35-44.
[8]KALS R, VOLLERTSEN F, GEIGER M. Scaling Effects in Sheet Metal Forming[C]//Proceedings of the 4th International Conference of Sheet Metal. Enschede, 1996:65-75.
[9]KALS T A, ECKSTEIN R. Miniaturization in Sheet Metal Working[J]. Journal of Materials Processing Technology, 2000, 103(1):95-101.
[10]RAULEA L V, GOIJAERTS A M, GOVAERT L E, et al. Size Effects in the Processing of Thin Metal Sheet[J]. Journal of Materials Processing Technology, 2001, 115:44-48.
[11]GEIGER M, ECKSTEIN R. Microforming:Advanced Technology of Plasticity[C]//Proceedings of the 7th ICTP. Yokohama, 2002:327-338.
[12]PERNIN N, CHEMBERT J, PICART P. Modeling of Micro-forming by Plasticity Gradient and Surface Layer Methods[C]//8th International Conference on Material Forming. Cluj-Napoca, 2005:109-112.
[13]刘平, 任凤章, 贾淑果. 铜合金及其应用[M]. 北京:化学工业出版社, 2007.
LIU Ping, REN Fengzhang, JIA Shuguo. Copper Alloy and Its Application[M]. Beijing:Chemical Industry Press, 2007.
[14]陈少华, 冯彪. 单轴拉伸下剪切带的应变梯度理论预测[C]//塑性力学新进展——2011年全国塑性力学会议. 北京, 2011:99-105.
CHEN Shaohua, FENG Biao. Theoretical Prediction of Strain Gradient of Shear Zone under Uniaxial Tension[C]//New Progress of Plastic Mechanics—2011 National Conference on Plastic Mechanics. Beijing, 2011:99-105.
[15]周健. 铜箔力学性能的尺寸效应及微拉深成形研究[D]. 哈尔滨:哈尔滨工业大学, 2010.
ZHOU Jian. Research on Size Effects of Mechanical Property and Micro Deep Drawing of Copper Foil[D]. Harbin:Harbin Institute of Technology, 2010.
[16]黄晓旭. 金属强度的尺寸效应[J]. 金属学报, 2014, 50(2):137-140.
HUANG Xiaoxu. Size Effects on the Strength of Metals[J]. Acta Metallurgica Sinica, 2014, 50(2):137-140.
[17]ARMSTRONG R W. Theory of the Tensile Ductile-brittle Behavior of Poly-crystalline h.c.p. Materials, with Application to Beryllium[J]. Acta Metallurgica, 1968, 16(3):347-355.
[18]郭斌, 周健, 单德彬, 等. 黄铜箔拉伸屈服强度的尺度效应[J]. 金属学报, 2008, 44(4):419-422.
GUO Bin, ZHOU Jian, SHAN Debin, et al. Size Effects of Yield Strength of Brass Foil in Tensile Test[J]. Acta Materialia, 2008, 44(4):419-422.
[19]刘芳, 魏子云, 李跃凯. 微细黄铜板料尺寸效应[J]. 塑性工程学报, 2010, 17(6):18-22.
LIU Fang, WEI Ziyun, LI Yuekai. Size Effects Research on the Micro Sheet Metal H62 Brass[J]. Journal of Plasticity Engineering, 2010, 17(6):18-22.
[20]GEIGER M, VOLLERTSEN F, KALS R. Fundamentals on the Manufacturing of Sheet Metal Microparts[J]. Annals of the CIRP, 1996, 45(2):227-282.
[21]KIM G Y, KOC M, MAYOR R, et al. Modeling of the Semi-solid Material Behavior and Analysis of Micro/Meso-scale Feature Forming[J]. Journal of Manufacturing Science & Engineering, 2007, 129(2):237-245.
[22]LAI X M, PENG L F, HU P, et al. Material Behavior Modeling in Micro/Meso-scale Forming Process with Considering Size/Scale Effects[J]. Computational Materials Science, 2008, 43(4):1003-1009.
[23]JANSSEN P J M, KEIJSER T H D, GEERS M G D. An Experimental Assessment of Grain Size Effects in the Uniaxial Straining of Thin Al Sheet with a Few Grains Across the Thickness[J]. Materials Science & Engineering A, 2006, 419(1/2):238-248.
[24]董培龙. 微塑性成形本构关系及超薄板微弯曲成形研究[D].镇江:江苏大学, 2009.
DONG Peilong. Study on the Constitutive Behavior in Micro Forming and Micro Bending of Ultra-thin Sheet[D]. Zhenjiang:Jiangsu University, 2009.
[25]李明星. SUS304不锈钢箔微冲裁尺寸效应研究[D]. 哈尔滨:哈尔滨工业大学, 2011.
LI Mingxing. Research on Size Effect in Micro Blanking of SUS304 Stainless Steel Foil[D]. Harbin:Harbin Institute of Technology, 2011.
[26]孟庆当, 李河宗, 董湘怀,等. 304不锈钢薄板微塑性成形尺寸效应的研究[J]. 中国机械工程, 2013, 24(2):280-283.
MENG Qingdang, LI Hezong, DONG Xianghuai, et al. Investigation of Size Effects of 304 Stainless Steel Foils in Microforming Process[J]. China Mechanical Engineering, 2013, 24(2):280-283.