Microstructural evolution and sintering kinetics during spark plasma sintering of Fe and Al blended powder  

放电等离子烧结Fe-Al混合粉的显微组织演化及烧结动力学（英文）

作　　者：Rui-di LI Tie-chui YUAN Xiao-jun LIU Ji-wei WANG Hong WU Fan-hao ZENG Xiang ZHOU 李瑞迪;袁铁锤;刘晓军;王基维;吴宏;曾凡浩;周祥(中南大学粉末冶金国家重点实验室,长沙410083;深圳信息职业技术学院,深圳518172)

机构地区：[1]State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China [2]Shenzhen Institute of Information Technology, Shenzhen 518172, China

出　　处：《Transactions of Nonferrous Metals Society of China》2017年第7期1594-1601,共8页中国有色金属学报（英文版）

基　　金：Projects(51474245,51571214)supported by the National Natural Science Foundation of China;Projects(2015GK3004,2015JC3006)supported by the Science and Technology Project of Hunan Province,China;Project(2016YFB1100101)supported by the National Key Research and Development Program,China;Project(K1502003-11)supported by the Changsha Municipal Major Science and Technology Program,China;Project(CSUZC2015030)supported by the Open-End Fund for the Valuable and Precision Instruments of CSU,China;Projects(2015CX004,2016CX003)supported by the Project of Innovation-driven Plan in CSU,China

摘　　要：The reaction diffusion between Fe and Al during spark plasma sintering(SPS)was studied.Microstructural evolution wasinvestigated by X-ray diffraction(XRD)and scanning electron microscopy(SEM)and the sintering kinetics was disclosed.The maininterphase of the SPS sample was Fe2Al5at773-873K.Ball-milling enabled a large number of lattice defects and grain boundariesthus the reaction kinetics was accelerated,although the direct current can also promote those defects.After milling,the phasetransformation kinetics was improved from0.207before mill to4.56×10-3.Besides,this work provided more details for thegeneration of Joule heating.The resistance offered to the electric path was considered to be the source of Joule heating,andparticularly the resistance offered by the different contact interfaces of die,punch,graphite foil and the sample played a leading rolefor the generation of Joule heating during spark plasma sintering.研究了Fe与Al混合粉在放电等离子烧结(SPS)作用下的反应扩散行为。采用X射线衍射及扫描电镜对显微组织演化进行了分析,并揭示了烧结动力学行为。结果表明在SPS温度773~873 K下,Fe2Al5为反应中间相。尽管电流可以提高材料扩散速度,球磨处理可在粉体中产生大量点阵缺陷及晶粒边界,使反应动力学速度得到提高。球磨后,相变动力学速度从球磨前的4.56×10^(-3)提高到0.207。而且,本研究揭示了焦耳热产生行为。作为电流通道,阻抗是重要的焦耳热源。SPS过程中粉末颗粒、模具、冲头、石墨纸之间界面阻抗是焦耳热产生的重要来源。

关 键 词：Fe-Al blended powder spark plasma sintering sintering kinetics DIFFUSION reaction Joule heating 

分 类 号：TF124.5[冶金工程—粉末冶金]