Si对铝热反应法制备的块体纳米晶Fe-Al-Cr，Fe-Al-Mn材料组织和性能的影响  

Effect of Si element on microstructure and mechanical properties of bulk nanocrystalline Fe-Al-Cr,Fe-Al-Mn materials prepared by aluminothermic reaction

作　　者：李翠玲[1] 喇培清[1] 刘辉[1] 魏玉鹏[1] 白亚平[1] 卢学峰[1] 陈经民[1] 

机构地区：[1]f兰州理工大学甘肃省有色金属新材料国家重点实验室,兰州730050

出　　处：《粉末冶金材料科学与工程》2011年第6期892-899,共8页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(50674051)

摘　　要：通过铝热反应法分别制备未加Si和加Si的块体纳米晶Fe-Al-Cr和Fe-Al-Mn材料。利用OM,XRD,EPMA和TEM对制得的材料进行微观组织观察。结果表明:加入质量分数为5%的Si之后,2种材料的平均晶粒尺寸变化不大;含10%Cr的材料晶体结构没有发生变化,均由无序bcc结构组成,而含15%Mn材料的晶体结构由之前的有序DO3结构向B2结构转变;Si元素的加入可降低Cr、Mn元素在Fe3Al中的溶解度,使基体中有Cr、Mn相析出。对材料进行硬度和应力应变曲线的测试,发现加入5%Si后,各材料的硬度均有较大程度的提高,塑性显著降低;含10%Cr的材料屈服强度由790 MPa减小至642 MPa,而含15%Mn的材料屈服强度由708 MPa增大至808 MPa。Bulk nanocrystalline Fe-Al-Cr and Fe-Al-Mn materials with and without Si element were prepared by aluminothermic reaction, respectively. Microstructures of the materials were investigated by optical microscope, electron probe microscope X-ray diffraction and transmission electron microscope. The results show that, after adding 5%Si （mass fraction, the same below）, the average grain size of two materials have no obvious change; the crystal structure of materials with 15%Mn changed from DO3 to B2, while the materials with 10%Cr had no change; the addition of Si element results in the precipitation of phases containing Cr, Mn element in the materials. Hardness and compressive properties of the materials were also tested, which indicates that, after adding 5%Si element, the hardness of both materials increases sharply, and the plasticity of the materials reduced significantly; the yield strength of the material with 10%Cr dropped from 790 to 642 MPa, while the material with 15%Mn increased from 708 to 808 MPa.

关 键 词：纳米晶Fe3Al SI元素 组织 力学性能 

分 类 号：TG113.25[金属学及工艺—物理冶金]