压缩载荷下织构对冷轧和退火板力学行为各向异(3)
【作者】网站采编
【关键词】
【摘要】图6所示为考虑{110}〈111〉滑移和/或{112}〈111〉孪生变形机制时和共4 种情况)计算的冷轧和退火织构Cu 板板平面内不同方向的Taylor 因子。需指出的是:随着
图6所示为考虑{110}〈111〉滑移和/或{112}〈111〉孪生变形机制时和共4 种情况)计算的冷轧和退火织构Cu 板板平面内不同方向的Taylor 因子。需指出的是:随着ξ减小,其Taylor 因子均降低,这并不意味着使金属产生塑性变形的外力越来越低。这是因为随着应变率增加,由于Cu为应变速率正敏感性材料,其滑移和孪生的临界分解剪切应力也随之增大,导致其产生塑性变形的外力也相应增大。显然,对于冷轧织构多晶Cu 板,随着ξ减小即塑性变形机制由滑移向滑移和/或孪生塑性变形机制转变,其Taylor 因子的变化规律是相似的,均表现出各向异性,且各向异性程度越来越低。对于退火织构多晶Cu 板,不管其塑性变形机制如何变化,其Taylor 因子变化较平缓,近似为各向同性。将Taylor 因子归一化,也可得到同样结论。
图5 仅考虑{110}〈111〉滑移时冷轧和退火Cu 板Taylor 因子Fig.5 Taylor-factors of cold-rolled and annealed Cu sheet considering{110}〈111〉slip1—退火织构板;2—冷轧织构板;3—随机分布结构。
图6 考虑{110}〈111〉滑移和/或{112}<111〉孪生时 Cu 板的Taylor 因子Fig.6 Taylor-factors of Cu sheets for{110}〈111〉slip and/or{112}〈111〉twinning(a)冷轧Cu 板;(b)退火Cu 板ξ:1—0.50;2—0.75;3—1.00;4—1.20
由上述分析可知:无论是准静态还是动态压缩变形,对于冷轧和退火织构Cu 板,考虑晶体取向分布即织构的影响,其各向异性规律与实验结果定性符合,可见本文分析结果与实际结果基本相符。
4 结论
1)退火织构多晶Cu 板3 个方向上的力学行为差别很小,近似为各向同性;相比较而言,冷轧织构多晶Cu 板准静态和动态压缩力学行为呈现出明显的各向异性,RD-90°方向屈服强度和流变应力最大,RD-45°方向的次之,RD-0°方向的最小。
2)考虑晶体取向分布即织构的影响,计算了板平面内与轧制方向成不同角度样品方向导致压缩塑性变形所需外力强度因子,结果可用于定性解释织构多晶Cu 板压缩力学行为各向异性。退火Cu 板表现出近似各向同性的原因是其再结晶织构和形变织构共同作用即两者之间相互平衡。
[1]HONG C S,TAO N R,LU K,et al.Grain orientation dependence of deformation twinning in pure Cu subjected to dynamic plastic deformation[J].Scripta Materialia,2009,61(3):289-292.
[2]H?RNQVISTA M,MORTAZAVI N,HALVARSSON M,et and texture evolution of OFHC copper during dynamic tensile extrusion[J].Acta Materialia,2015,89:163- 180.
[3]YAO B,HAN Z,LI Y S,et al.Dry sliding tribological properties of nanostructured copper subjected to dynamic plastic deformation[J].Wear,2011,271(9/10):1609-1616.
[4]LIN Fengxiang,ZHANG Yubin,TAO Nairong,et of heterogeneity on recrystallization kinetics of nanocrystalline copper prepared by dynamic plastic deformation[J].Acta Materialia,2014,72:252-261.
[5]STEVENSON M E,JONES S E,BRADT R C.The high strain rate dynamic stress-strain curve for OFHC copper[J].Materials Science Research International,2003,9(3):187-195.
[6]MEYERS M A,ANDRADE U R,CHOKSHI A R.The effect of grain size on the high-strain,high-strain-rate behavior of copper[J].Metallurgical and Materials Transaction A,1995,26(11):2881-2893.
[7]NEMAT-NASSER S,LI Y L.Flow stress of fcc polycrystals with application to OFHC Cu[J].Acta Materialia,1998,46(2):565-577.
[8]ALEXANDER D J,BEYERLEIN I in mechanical properties of high-purity copper processed by equal channel angular extrusion[J].Materials Science and Engineering A,2005,410/411:480-484.
[9]LI Y S,TAO N R,LU evolution and nanostructure formation in copper during dynamic plastic deformation at cryogenic temperatures[J].Acta Materialia,2008,56(2):230-241.
[10]LI Y S,ZHANG Y,TAO N R,et of thermal annealing on mechanical properties of a nanostructured copper prepared by means of dynamic plastic deformation[J].Scripta Materialia,2008,59(4):475-478.
[11]MISHRA A,MARTIN M,THADHANI N N,et response of ultra-fine-grained copper[J].Acta Materialia,2008,56(12):2770-2783.
[12]陈志永,才鸿年,王富耻,等.冷轧Cu板动态压缩力学性能各向异性的研究[J].金属学报,2009,45(2):143-150.
CHEN Zhiyong,CAI Hongnian,WANG Fuchi,et on anisotropy of dynamic compressive mechanical properties of cold-rolled Cu sheet[J].Acta Metallurgica Sinica,2009,45(2):143-150.
[13]TANG Lin,CHEN Zhiyong,ZHAN Congkun,et evolution in adiabatic shear bands of copper at high strain rates:electron backscatter diffraction characterization[J].Materials Characterization,2012,64:21-26.
[14]TANG Lin,CHEN Zhiyong,ZHAN Congkun,et and microtexture evolution of shear localization in dynamic deformation with different strains in annealed copper[J].Metallurgical and Materials Transactions A,2013,44(2):793-805.
[15]MA Zhichao,ZHAO Hongwei,LU Shuai,et of zinc on static and dynamic mechanical properties of copper-zinc alloy[J].Journal of Central South University,2015,22(7):2440- 2445.
文章来源:《固体力学学报》 网址: http://www.gtlxxbzz.cn/qikandaodu/2021/0226/444.html
上一篇:固体力学发展趋势断裂与损伤研讨会在清华大学
下一篇:基于模型的钢本构参数识别及验证