保温时间对B2结构FeAl金属间化合物组织及性能的影响  

Effect of Holding Time of Hot Pressing Sintering on Microstructure and Properties of B2 Structure FeAl Intermetallics

作　　者：周瑾 白亚平[1] 成超 李建平[1] 杨忠[1] ZHOU Jin;BAI Yaping;CHENG Chao;LI Jianping;YANG Zhong(School of Materials and Chemical Engineering,Xi’an Technological University,Xi’an 710021,China)

机构地区：[1]西安工业大学材料与化工学院,西安710021

出　　处：《西安工业大学学报》2020年第3期274-281,共8页Journal of Xi’an Technological University

基　　金：国家自然科学基金(51705391);装备预研领域基金重点项目(6140922010301);陕西省创新人才推进计划-科技创新团队项目(2017KCT-05);陕西高校“金属腐蚀防护及表面工程技术”青年创新团队项目。

摘　　要：为了研究保温时间t对FeAl金属间化合物显微组织及力学性能的影响规律,文中通过机械合金化与热压烧结相结合的方法制备FeAl金属间化合物,在25MPa、1 050℃的热压烧结条件下分别保温1h、1.5h、2h、2.5h和3h,研究其显微组织及力学性能的变化规律。采用扫描电镜进行显微组织观察和断口形貌分析,利用能谱仪和X射线衍射仪进行物相分析,并测试不同保温时间下FeAl金属间化合物的硬度、密度以及室温拉伸性能。研究结果表明:制备的FeAl块体中,以B2结构的FeAl金属间化合物为主,同时含有少量的Al2O3和AlFe3C0.5;各物相的分布会随着时间的增加越来越均匀;密度随着保温时间的增加呈现先增加再平稳的趋势,在2h时密度趋于稳定;FeAl的硬度、抗拉强度随保温时间的增加先增后降;当保温时间为2.5h时,FeAl的硬度达到最大值37.4HRC,抗拉强度达到最大值439.2MPa;通过断口形貌分析发现B2结构FeAl金属间化合物的断裂方式为沿晶脆性断裂,断裂机理为解理断裂。In order to study the effect of holding time on the microstructure and mechanical properties of FeAl Intermetallics,FeAl intermetallic compound was prepared by mechanical alloying and hot pressing sintering.The microstructure and mechanical properties of the samples were studied when they were hot pressing sintered at 25 MPa and 1050℃for 1 h,1.5 h,2 h,2.5 h and 3 h.Their microstructure and fracture morphology were observed with an SEM,their phase was analyzed by using an EDX and an XRD,and the hardness,density and room temperature tensile properties of FeAl intermetallics at different holding times were tested.The results are as follows.The main structure of the FeAl block is the FeAl intermetallics of B2 structure,containing a small amount of Al 2O 3,and AlFe 3C 0.5.With the increase of holding time,the distribution of each phase becomes increasingly uniform,and the density increases first and then tends to be and becomes stable in 2 hours.The hardness and tensile strength of FeAl increase first and then decrease with the increasing holding time.When the holding time reaches 2.5 hours,its hardness reaches the maximum value of 37.4 HRC,and its tensile strength reaches the maximum value of 439 MPa.The results show that the fracture mode of B2 structure FeAl intermetallic compound is intergranular brittle fracture,and its fracture mechanism is cleavage fracture.

关 键 词：FEAL金属间化合物 保温时间 显微组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]