沿热轧退火态AZ31镁合金轧制方向进行室温动态塑性变形，采用场发射扫描电子显微镜研究{1012}孪生的变体类型及结构特征。结果表明：在{1012}孪生机制主导塑性变形的初级阶段(ε＜8%)，AZ31镁合金中大部分晶粒内部仅产生一种{1012}孪生变体或变体对，所以孪晶结构呈彼此平行状，将晶粒分割成片层组织；这种片层组织的厚度随着应变量的增加而减小，从5.55μm减小到2.49μm；少数晶粒形核产生不同的{1012}孪生变体，且这种晶粒的数量随着塑性变形量的增大而增加；当ε＞8%，孪生体积分数接近饱和，位错滑移成为镁合金主要的变形机制。
Both variant type and structure characteristic of {10 1 2} twinning in the as-rolled AZ31 magnesium alloy subjected to dynamic plastic deformation at room temperature along the rolling direction were investigated. The results show that at the stage of twinning-dominated deformation (ε<8%), mostly a {10 1 2} twin variant or a twin variant pair is activated in the grain of AZ31 magnesium alloy, leading to a parallel twin lamellar structure. The lamellar thickness decreases significantly from 5.55μm to 2.49μm with increasing the strain. Meanwhile, different {10 1 2} variant pairs also generate in some grains, and the number of these grains increases with increasing the plastic strain. When the plastic strain is greater than 8%, the volume fraction of twins almost saturates and dislocation slips dominate the later deformation.
参考文献
| [1] | BARNETT M R .Twinning and the ductility of magnesium alloys Part Ⅰ:"Tension” twins[J].Materials Science and Engineering A,2007,464(1/2):1-7. |
| [2] | BARNETT M R .Twinning and the ductility of magnesium alloys Part Ⅱ:"Contraction” twins[J].Materials Science and Engineering A,2007,464(1/2):8-16. |
| [3] | 陈振华,夏伟军,程永奇,傅定发.镁合金织构与各向异性[J].中国有色金属学报,2005(01):1-11. |
| [4] | YOO M H .Slip,twinning,and fracture in hexagonal close-packed metals[J].Metallurgical Transactions A,1981,12(03):409-418. |
| [5] | 丁文江,靳丽,吴文祥,董杰.变形镁合金中的织构及其优化设计[J].中国有色金属学报,2011(10):2371-2381. |
| [6] | 郭飞;张丁非;杨绪盛;蒋璐瑶 潘复生 .大应变热轧过程中 AZ31镁合金显微组织及织构变化[J].中国有色金属学报,2015,25(01):14-21. |
| [7] | J. A. del Valle;F. Carreno;O. A. Ruano .Influence of texture and grain size on work hardening and ductility in magnesium-based alloys processed by ECAP and rolling[J].Acta materialia,2006(16):4247-4259. |
| [8] | LOU C;ZHANG X Y;WANG R H;LIU Q .Mechanical behavior and microstructural characteristics of magnesium alloy containing {10 12} twin lamellar structure[J].Journal of Materials Research,2013,28(05):733-739. |
| [9] | 卢立伟,赵俊,刘龙飞,王尧,刘天模.冷锻及再结晶退火对挤压态AZ31镁合金组织的影响[J].中国有色金属学报,2014(12):2969-2977. |
| [10] | LU K;LU L;SURESH S .Strengthening materials by engineering coherent internal boundaries at the nanoscale[J].SCIENCE,2009,324:349-352. |
| [11] | L. Lu;X. Chen;X. Huang;K. Lu .Revealing The Maximum Strength In Nanotwinned Copper[J].Science,2009(5914):607-610. |
| [12] | SONG H Y;LI Y L .Effect of twin boundary spacing on deformation behavior of nanotwinned magnesium[J].Physics Letters A,2012,376(04):529-533. |
| [13] | DUDAMELL N V;ULACIA I;GáLVEZ F;YI S BOHLEN J LETZIG D HURTADO I PEREZ-PRADO M T .Twinning and grain subdivision during dynamic deformation of a Mg AZ31sheet alloy at room temperature[J].Acta Materialia,2011,59(18):6949-6962. |
| [14] | LOU C;ZHANG X Y;DUAN G L;TU J LIU Q .Characteristics of different {10 12} twin variants in magnesium alloy during room temperature dynamic plastic deformation[J].Journal of Materials Research,2013,28(14):1885-1890. |
| [15] | HONG S G;PARK S H;LEE C S .Role of {10 12} twinning characteristics in the deformation behavior of a polycrystalline magnesium alloy[J].Acta Materialia,2010,58:5873-5885. |
| [16] | XIAO G H;TAO N R;LU K .Microstructures and mechanical properties of a Cu-Zn alloy subjected to cryogenic dynamic plastic deformation[J].Materials Science and Engineering A,2009,513/514:13-21. |
| [17] | Leon L. Shaw;Angel L. Ortiz;Juan C. Villegas .Hall-Petch relationship in a nanotwinned nickel alloy[J].Scripta materialia,2008(11):951-954. |
| [18] | LOU C;ZHANG X Y;WANG R H;LIU Q .Characteristics of{10 12} twin lamellar structure in magnesium alloy during room temperature dynamic plastic deformation[J].Journal of Materials Science&Technology,2014,30(01):41-46. |
| [19] | FERNáNDEZ A;JéRUSALEM A;GUTIéRREZ-URRUTIA I;PéREZ-PRADO M T .Three-dimensional investigation of grain boundary-twin interactions in a Mg AZ31alloy by electron backscatter diffraction and continuum modeling[J].Acta Materialia,2013,61:7679-7692. |
| [20] | L. Capolungo;P.E. Marshall;R.J. McCabe .Nucleation and growth of twins in Zr: A statistical study[J].Acta materialia,2009(20):6047-6056. |
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