电极感应熔炼气雾化法制备Ti-48Al-2Cr-2Nb金属间化合物粉末的特性表征  

Characterization of Ti-48Al-2Cr-2Nb Intermetallic Powders by Electrode Induction Melting Gas Atomization

作　　者：王虎 彭云[1] 赵琳[1] 田志凌[1] Wang Hu;Peng Yun;Zhao Lin;Tian Zhiling(Welding Research Institute,Central Iron&Steel Research Institute,Beijing 100081,China;College of Materials Engineering,North China Institute of Aerospace Engineering,Langfang 065000,China)

机构地区：[1]钢铁研究总院焊接研究所,北京100081 [2]北华航天工业学院材料工程学院,河北廊坊065000

出　　处：《稀有金属》2024年第12期1702-1712,共11页Chinese Journal of Rare Metals

基　　金：国家重点研发计划项目(2017YFB1103300);中央引导地方科技发展资金项目(246Z1816G);北华航天工业学院科研基金项目(CXPT202402,ZD202301)资助。

摘　　要：采用电极感应熔炼气雾化(EIGA)法制备出Ti-48Al-2Cr-2Nb金属间化合物粉末,利用激光粒度分析仪、电感耦合等离子体发射光谱仪(ICP-AES)、氧氮氢分析仪、扫描电子显微镜(SEM)、金相显微镜(OM)、X射线衍射仪(XRD)和纳米压痕仪对粉末特性进行表征。结果表明,粉末粒径主要分布在15~105μm之间,并呈现正态分布特征,D_(10),D_(50)和D_(90)(D_(10),D_(50)和D_(90)分别为粉末累积分布达到10%,50%和90%时对应的粒径值)分别为16.50,45.51和108.95μm;粉末形状以球形或近球形为主,但同时也出现少量形状异常粉末,如卫星粉、椭球形粉末、包裹式粉末、孪生式粉末。粉末中O,N和H的平均含量分别为0.092%,0.0058%和0.002%,其中O含量随着粉末粒径的增加而减少,N和H含量随粉末粒径的变化不大。随着粉末粒径增加,粉末表面逐渐由光滑转变为凹凸不平的冷凝收缩痕迹,截面组织按照“微晶—胞状树枝晶—树枝晶”的顺序演变,粉末空心率逐渐增大。当粉末粒径(d)≤75μm时,粉末物相主要由α_(2)相以及少量γ相组成,随着粉末粒径增加,α_(2)相含量逐渐减少,γ相含量逐渐增多,当d≥75μm时,粉末主相转变为γ相。此外随着粉末粒径增加,纳米硬度和弹性模量逐渐减小。As a novel light-weight and high-temperature structural material,the TiAl intermetallics have the characteristics of low density,high specific strength and specific modulus,excellent high-temperature mechanical properties,and so on.The TiAl intermetallics show broad application potential in aerospace,automotive industry,and other fields,which are expected to partially replace nickel-based superalloys,titanium alloys and heat-resistant steels.However,TiAl intermetallics have high brittleness and poor ductility,so it is difficult to form by traditional forming processes,such as forging,rolling.TiAl intermetallics are mostlyfabricated by nearnet shape forming technologies,such as precision casting,powder metallurgy,additive manufacturing.Additive manufacturing has the advantages of low cost,short cycle and good flexibility,so it is especially suitable for the forming of TiAl intermetallics,which has gradually attracted extensive attention of scientific researchers in recent years.Additive manufacturing requires powders with high sphericity,good fluidity,low impurity element content,and suitable particle size.However,the preparation of special powders for additive manufacturing is difficult,because the cost is high,and the content of spherical powders is low,and the batch stability of powders is poor.Therefore,the preparation of special powders for additive manufacturing has become one of the key topics in the development and application of additive manufacturing.The TiAl intermetallic powders prepared by traditional gas atomization(GA)have high impurity element content,owing to the high reactivity between TiAl intermetallics and crucible(Al_(2)O_(3)).Therefore,TiAl intermetallic powders by crucible-less gas atomization technology are gradually favored by researchers at home and abroad.At present,crucible-less gas atomization technology mainly includes plasma rotating electrode processing(PREP)and electrode induction melting gas atomization(EIGA).The powders prepared by PREP have high sphericity,good surface morpholo

关 键 词：电极感应熔炼气雾化(EIGA)法 TiAl金属间化合物粉末 杂质元素含量 微观形貌 空心率 物相结构 纳米压痕 

分 类 号：TG146.2[一般工业技术—材料科学与工程]