混合熵对定向凝固锰铜基阻尼合金组织与性能的影响  

Effect of Mixed Entropy on the Microstructure and Performance of Directional Solidified Mn-Cu-based Damping Alloys

作　　者：牛红康 梅玲 吴蕾 王迪玮 田青超 NIU Hongkang;MEI Ling;WU Lei;WANG Diwei;TIAN Qingchao(State Key Laboratory of Advanced Special Steels,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444

出　　处：《有色金属工程》2023年第11期8-15,共8页Nonferrous Metals Engineering

摘　　要：使用动态热机械分析仪、光学显微镜(OM)、X射线衍射仪(XRD)和扫描电子显微镜(SEM)研究了不同成分梯度的定向凝固锰铜基合金的微观组织、阻尼行为以及力学性能特征。结果表明,在定向凝固过程中,随着合金元素的添加,枝晶间距逐渐减小,成分偏析程度增加,物相组成变为单一的母相,熵增引起的成分过冷使得枝晶易于断裂。添加镍与铁元素可以提高低温端孪晶的内耗值,而在加入锌元素后,MnCuNiFeZn合金在673 K下的内耗升高至0.023。随着混合熵的增加,三种不同成分梯度的定向凝固锰铜基合金的抗拉强度与伸长率均线性增加,合金应变硬化率的平稳保持段的斜率与混合熵呈正相关。The microstructure,damping behavior and mechanical properties of directionally solidified MnCu-based alloys with different chemical composition gradients were studied via using dynamic thermomechanical analyzer,Optical Microscope,X-Ray Diffractometer and Scanning Electron Microscope.The results show that during directional solidification,the dendrite spacing gradually decreases,the degree of component segregation increases,and the phase constituent becomes a single parent phase with the addition of alloying elements.The composition supercooling caused by entropy increase makes the dendrites prone to fracture.The addition of nickel and iron increases the internal friction value of the low-temperature twin,after adding Zn,the internal friction value of the MnCuNiFeZn alloy at 673 K rises to 0.023.With the increase of mixed entropy,the tensile strength and elongation of the three alloys increase linearly,and the slope of the stable holding section of the alloy strain hardening rate is positively correlated with the entropy of mixing.

关 键 词：锰铜基阻尼合金 定向凝固 混合熵 反铁磁转变 

分 类 号：TG146[一般工业技术—材料科学与工程]