脉冲磁场对TC4钛合金析出行为及力学性能的影响  

Effect of Pulsed Magnetic Field on Precipitation Behavior and Mechanical Properties of TC4 Titanium Alloy

作　　者：孙中豪 邢淑清[1] 程桥 苏怡卉 贺骁勇 麻永林[1] Sun Zhonghao;Xing Shuqing;Cheng Qiao;Su Yihui;He Xiaoyong;Ma Yonglin(College of Material and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010

出　　处：《稀有金属材料与工程》2022年第9期3336-3344,共9页Rare Metal Materials and Engineering

基　　金：内蒙古自治区自然科学基金(2018MS05008,2020MS05046)。

摘　　要：为了探讨脉冲磁场对TC4钛合金析出行为的影响,在其时效过程中施加了脉冲磁场,分别在形核阶段和长大阶段进行观察与分析,利用扫描电镜、透射电镜、拉伸试验机研究脉冲磁场在TC4时效过程中对显微组织、强度和塑性的的影响,并通过经典形核理论及扩散理论分析了脉冲磁场在时效过程中的作用机制。结果表明,由于脉冲磁场的加入,TC4析出速度明显提高,相同时间下析出相的体积分数增加,在保证力学性能的前提下,降低了时效所需的时间。施加脉冲磁场时效2 h相较于未施加脉冲磁场4 h延伸率塑性提高了21.68%,抗拉强度基本一致。在脉冲磁场和温度场耦合作用下时效,可使TC4提前(2h)进入过时效阶段;在拉伸断口方面,施加脉冲磁场在2h前断口形貌为韧窝断口,但当时间增加至2 h后,断口逐渐转变为准解理断口形貌,表明脉冲磁场可以加速时效进程。分析认为,脉冲磁场通过磁吉布斯自由能促进了TC4在时效过程中次生相的析出及长大,是由于降低临界形核功和促进原子扩散的协同效应所致。In order to investigate the effect of pulsed magnetic field on precipitation behavior of as-rolled TC4 titanium alloy,a pulsed magnetic field was applied during aging.The effects of electromagnetic energy on microstructure,strength and plasticity of TC4 during aging were studied by SEM,TEM and tensile testing machine.Observation and analysis were carried out at nucleation stage and growth stage.The mechanism of electromagnetic energy in aging process was analyzed by classical nucleation theory and the first law of diffusion.The results show that the precipitation rate of TC4 is significantly increased due to the addition of electromagnetic energy.The aging time is reduced on the premise of ensuring the mechanical properties.Compared with 4 h without pulse magnetic field,the elongation of 2 h with pulse magnetic field is increased by 21.68%,and the tensile strength is approximately the same.The aging process under the coupling of pulse magnetic field and temperature field can lead TC4 to over aging stage(2 h).In the aspect of tensile fracture,the fracture morphology of fracture is dimple fracture before applying pulse magnetic field 2 h ago,but when the time increases to 2 h,the fracture surface gradually changes to the fracture morphology in quasi solution.The results reveal that the secondary phase precipitation and growth of TC4 can be promoted by pulsed magnetic field through electromagnetic energy,which is due to the synergistic effect of reducing critical nucleation work and promoting atomic diffusion.Overall,electromagnetic energy can promote the precipitation of secondary phase and reduce the aging time.

关 键 词：TC4钛合金 脉冲磁场 力学性能 析出行为 

分 类 号：TG146.23[一般工业技术—材料科学与工程]