Cu-Zr-Cr合金热变形行为及微观组织研究  

Hot Deformation Behavior and Microstructure of Cu-Zr-Cr Alloy

作　　者：李承润 雷嘉龙 孙雯雯 李政遨 周孟 景柯 LI Chengrun;LEI Jialong;SUN Wenwen;LI Zheng'ao;ZHOU Meng;JING Ke(School of Materials Science and Engineering,Henan University of Science and Technology,Henan Luoyang 471023,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023

出　　处：《精密成形工程》2024年第9期84-94,共11页Journal of Netshape Forming Engineering

基　　金：河南省自然科学基金(232300420089);中国博士后科学基金(2023TQ0107)。

摘　　要：目的探究应变速率、变形温度及Cr含量对Cu-Zr-Cr合金组织与性能的影响。方法采用真空熔炼法制备了Cu-0.3Zr-0.05Cr和Cu-0.3Zr-0.15Cr合金。热锻后,使用Gleeble-1500型热模拟试验机分别对2种合金在温度为750~900℃、反应速率为0.003~1 s^(−1)的条件下进行热压缩实验。绘制了2种合金在不同热变形条件下的真应力-真应变曲线,建立了本构方程,绘制了Cu-0.3Zr-0.15Cr合金的热加工图,观察并分析了合金的微观组织。对温度850℃、应变速率1 s^(−1)条件下热压缩Cu-0.3Zr-0.15Cr合金进行了TEM观察。结果流变应力随变形温度的升高而降低,随应变速率的增大而增大。Cu-0.3Zr-0.05Cr和Cu-0.3Zr-0.15Cr合金的热激活能分别为488.9 kJ/mol和491.3 kJ/mol,确定了Cu-0.3Zr-0.15Cr合金的最佳加工区域。当Cu-0.3Zr-0.05Cr和Cu-0.3Zr-0.15Cr合金在850℃、应变速率1 s^(−1)下进行热压缩实验时,垂直于压缩方向的晶粒尺寸分别为25μm和21.4μm。Cu-0.3Zr-0.15Cr合金中存在2种析出相,分别为细小Cr析出相和粗大未溶解的Cu5Zr相,尺寸分别约为10 nm和840 nm。结论Cu-Zr-Cr合金在850℃、应变速率为1 s^(−1)的条件下进行热变形时具有较好的晶粒细化效果,Cr元素的增加会细化晶粒并且提高合金的热激活能,改善合金的热加工性能。The work aims to investigate the effects of strain rate,deformation temperature and Cr content on the microstructure and properties of Cu-Zr-Cr alloy.Cu-0.3Zr-0.05Cr and Cu-0.3Zr-0.15Cr alloys were prepared by vacuum melting.After hot forging,the hot compression experiments of the two alloys were carried out at 750-900℃under the reaction rate of 0.003-1 s^(−1) by Gleeble-1500 thermal simulation testing machine.True stress-strain curves of the two alloys under different hot deformation conditions were plotted experimentally,and a constitutive equation was established,and a hot processing map of Cu-0.3Zr-0.15Cr alloy was drawn.The microstructure of the alloys was observed and analyzed.The TEM observation of the hot-compressed Cu-0.3Zr-0.15Cr alloy at 850℃under the strain rate of 1 s^(−1) was carried out.It was found that the flow stress decreased with the increase of deformation temperature and increased with the increase of strain rate.The thermally activated energies of Cu-0.3Zr-0.05Cr alloy and Cu-0.3Zr-0.15Cr alloy were 488.9 kJ/mol and 491.3 kJ/mol,respectively.The optimal machining area of Cu-0.3Zr-0.15Cr alloy was determined.The study found that the grain sizes perpendicular to the compression direction of Cu-0.3Zr-0.05Cr and Cu-0.3Zr-0.15Cr alloys were 25μm and 21.4μm,respectively,when the hot compression test was performed at 850℃under the strain rate of 1 s^(−1).There were two precipitated phases in Cu-0.3Zr-0.15Cr alloy,which were fine Cr precipitated phases and coarse undissolved Cu5Zr phases,with sizes of about 10 nm and 840 nm,respectively.In conclusion,Cu-Zr-Cr alloy has a good grain refinement effect when it is thermally deformed at 850℃under a strain rate of 1 s^(−1),and the increase of Cr element will refine the grains,increase the heat activation energy of the alloy,and improve the hot processing performance of the alloy.

关 键 词：Cu-Zr-Cr合金 热变形 微观组织 流变应力 本构方程 

分 类 号：TG146.1[一般工业技术—材料科学与工程]