CNTs对多道次低温轧制Mg-2Zn合金板材动态再结晶及力学性能的影响  

Effects of CNTs on dynamic recrystallization and mechanical properties of Mg-2Zn alloy sheet produced by multi-pass rolled at low temperature

作　　者：李浩 刘轲[1] 杜文博[1] 李淑波[1] 杜宪[1] 刘辉 LI Hao;LIU Ke;DU Wenbo;LI Shubo;DU Xian;LIU Hui(College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China;Xinjiang Kunyu Iron&Steel Co.,Ltd.,Xinjiang 833200,China)

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]新疆昆玉钢铁有限公司,新疆833200

出　　处：《中国有色金属学报》2024年第10期3294-3307,共14页The Chinese Journal of Nonferrous Metals

摘　　要：采用多道次轧制技术制备了不同碳纳米管(CNTs)含量的Mg-2Zn基复合材料板材,利用EBSD、TEM等技术研究了板材的微观组织演变规律,结合拉伸实验分析了板材的强化机理。结果表明:在轧制过程中晶界处的CNTs能够阻碍位错运动,使位错在晶界处堆积,导致局部应力集中,促进变形孪晶的产生。变形孪晶诱发动态再结晶(DRX)发生,在孪晶内和孪晶界区域发剧烈的动态再结晶(DRX),导致终态高CNTs含量(CNTs含量为0.6%)的板材的基面织构强度趋弱。CNTs主要影响了板材的织构状态,随着CNTs含量的增加,板材的(0001)基面强度逐渐降低,从轧向(RD)向横向(TD)劈裂,降低了基面织构的强度。在CNTs、细晶和织构强化下,0.4%CNTs/Mg-2Zn复合材料的抗拉强度为283 MPa、屈服强度为260 MPa、伸长率为4%。A multi-pass rolling was performed to fabricate the Mg-2Zn matrix composites with different contents of carbon nanotubes(CNTs).The microstructure evolution of these composite sheets was investigated by using electron backscatter diffraction(EBSD),transmission electron microscope(TEM)and other characterization techniques.The results show that the CNTs at grain boundaries can hinder the movement of dislocations during hot rolling process.These dislocations are generally accumulated at grain boundaries,resulting in local stress concentrations which promotes the generation of the deformation twining.The dynamic recrystallization(DRX)is induced by the deformation twins,and severe DRX occurs within the twins and at the twin boundary,resulting in the weak basal textural strength of plates with high CNTs content(0.6%)in the final state.CNTs mainly affect the texture of the plate,with the increase of CNTs content,the(0001)base strength of the plate gradually decreases,and the splitting from rolling(RD)to transverse(TD)decreases the strength of the base texture.The 0.4%CNTs/Mg-2Zn composite exhibits a weaker basal texture and the best mechanical properties.Under the strengthening of CNTs,fine grain and texture,the tensile strength,yield strength and the elongation of 0.4%CNTs/Mg-2Zn composites are 283 MPa,260 MPa and 4%,respectively.

关 键 词：MG基复合材料 CNTS 轧制变形 动态再结晶 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]