电极感应熔化气雾化粉末特性及液滴尺寸影响因素的研究  

Study on Powder Characteristics and Effect Factors of Droplets Size During Electrode Induction Melting Gas Atomization

作　　者：杨乐彪 任晓娜 夏敏[2] 孙海涛 吕晓安 葛昌纯[2] Yang Lebiao;Ren Xiaona;Xia Min;Sun Haitao;Lv Xiaoan;Ge Changchun(University of Science and Technology Beijing,Beijing 100083,China;Institute of Powder Metallurgy and Advanced Ceramics,School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学材料科学与工程学院,粉末冶金与先进陶瓷研究所,北京100083 [2]北京科技大学,北京100083

出　　处：《稀有金属材料与工程》2020年第6期2017-2023,共7页Rare Metal Materials and Engineering

基　　金：中央高校科研基金(FRF-TP-17-044A1)。

摘　　要：对电极感应熔化气雾化(electrode induction melting gas atomization,EIGA)工艺制备的镍基高温合金粉末的物理特性,凝固组织以及内部元素分布进行研究;理论分析了EIGA制粉一次雾化过程中液滴尺寸的影响因素;根据对流换热原理计算了该工艺中不同尺寸粉末的冷却速率。结果表明:EIGA粉末以近球形为主,霍尔流速为13.4 s/50 g,D90=121.5μm。粉末表面和内部凝固组织显示,随着粉末尺寸的增大,组织均由微晶向胞状晶和树枝晶转变。同时颗粒表面组织之间的间隙不断加深,粉末光滑度下降。在雾化气压为4 MPa条件下,粉末尺寸与冷却速率的关系为:|dtd/dt|=8.98×10^-5/d^2。粉末内部没有明显的成分偏析现象,但晶轴和晶间的元素分布略有差别。晶轴上Ni、Al、Co、C元素含量较晶间高,晶间的Ti、Mo、Cr、Nb元素含量更高。We investigated the physical characteristics,solidification microstructure,and inner element distribution of Ni-based superalloy powders,which were prepared by electrode induction melting gas atomization(EIGA)process.Some effect factors on metal droplet size during primary atomization were also analyzed.The cooling rate of powders with different sizes was calculated through convective heat transfer principle.Results show that the EIGA powders are mainly spherical,the Hall flow rate is 13.4 s/50 g,and the D90 is 121.5μm.The microstructure of powders changes from microcrystals to cell crystals and dendrites with increasing the powder size.At the same time,the smoothness of powders decreases as the gap increases on the surface.The relationship between cooling rate and particle size is |dtd/dt|=8.98×10^-5/d^2,when the atomization gas pressure is 4 MPa.There is slight segregation in crystal axis and among crystals of powders.The content of Ni,Al,Co,and C in crystal axis is higher than that of the intergranular,while the intergranular content of Ti,Mo,Cr,and Nb is much higher.

关 键 词：高温合金粉末 一次雾化 成分偏析 液膜 冷却速率 

分 类 号：TG132.3+2[一般工业技术—材料科学与工程] TF123.1+12[金属学及工艺—合金]