氧化镁坩埚与镍基高温合金界面反应机理  

Interaction Mechanism Between MgO Crucible and Ni-Based Superalloy

作　　者：陈光耀 廖厚劲 邓少文 冯齐胜 高鹏越 王恩会 赵云松[4] 侯新梅[3] 李重河 CHEN Guangyao;LIAO Houjin;DENG Shaowen;FENG Qisheng;GAO Pengyue;WANG Enhui;ZHAO Yunsong;HOU Xinmei;LI Chonghe(State Key Laboratory of Advanced Special Steel&Shanghai Key Laboratory of Advanced Ferrometallurgy,School of Materials Science and Engineering,Shanghai University,Shanghai 200072,China;Shanghai Special Casting Engineering Technology Research Center,Shanghai 201605,China;Institute for Carbon Neutrality,University of Science and Technology Beijing,Beijing 100083,China;Science and Technology on Advanced High Temperature Structural Materials laboratory,Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]上海大学材料科学与工程学院,省部共建高品质特殊钢冶金与制备国家重点实验室,上海市钢铁冶金新技术开发应用重点实验室,上海200072 [2]上海市特种铸造工程技术研究中心,上海201605 [3]北京科技大学碳中和研究院,北京100083 [4]北京航空材料研究院先进高温结构材料重点实验室,北京100095

出　　处：《硅酸盐学报》2024年第12期3832-3840,共9页Journal of The Chinese Ceramic Society

基　　金：国家重点研发计划(2022YFB3404501);国家自然科学基金(52374360,U2341267,52104305)。

摘　　要：坩埚式感应熔炼镍基高温合金的纯净度与合金–坩埚界面反应程度密不可分,明确两者界面反应机理对实现高纯净度合金制备具有重要意义。采用MgO坩埚分别感应熔炼纯Ni和镍基高温合金,通过X射线衍射仪、扫描电子显微镜及氧/氮分析仪研究了坩埚与金属熔体接触前后相组成、显微形貌及金属中氧含量的变化规律,进而研究了2种金属与MgO坩埚间界面反应,明晰了界面反应机理。研究表明:使用Mg O坩埚熔炼纯Ni时,纯Ni熔体对坩埚内壁润湿,但并未见明显界面反应发生。而高温合金熔体与MgO坩埚存在界面反应,该反应以MgO在合金熔体中熔解–分解为主,分解O与熔体中Al反应形成Al_(2)O_(3),其中:一部分Al_(2)O_(3)会上浮至合金表面;另一部分Al_(2)O_(3)会与MgO坩埚基体反应生成MgAl_(2)O_(4),同时,该生成物一部分附着在坩埚内壁;另一部分也受电磁搅拌进入合金表面,最终在合金表面形成由Al_(2)O_(3),MgAl_(2)O_(4)和一部分合金混合而成的厚度约80μm的浮渣层。Introduction The purity of the Ni-based superalloy is directly related to the alloy-crucible interaction during induction melting.It is thus of great significance to clarify the interaction mechanism for the achievement of preparing the high-purity superalloys.In this study,pure Ni and Ni-based superalloys were melted in MgO crucibles,respectively.The phase composition,microstructure of the crucible and the oxygen concentration of the metals were analyzed by scanning electron microscopy,X-ray diffractometry and O/N analyzer.The interaction between the metals and the crucibles were investigated,and the interaction mechanism was elucidated.The results indicate that after melting pure Ni in MgO crucible,pure Ni melt exhibits a good wettability to the crucible,but little interaction occurs.However,a significant interaction between the superalloy melt and MgO crucible occurs.This reaction primarily involves the dissolution and decomposition of MgO in the alloy melt.The decomposed element O reacts with element Al to form Al_(2)O_(3)products,which can float to the surface of the superalloy.Also,some Al_(2)O_(3)can further react with MgO crucible matrix to generate MgAl_(2)O_(4)product,which can attach to the inner surface of the crucible,and float into the slag,respectively.A slag layer with the thickness of approximately 80μm composed of Al_(2)O_(3),MgAl_(2)O_(4),and a portion of the alloy can be formed on the surface of the alloy.Methods In this study,an industrial grade MgO(purity>99.5%)was used as a raw material.The MgO powder was mixed and ground in ethanol in a concrete mixer with yttria stabilized zirconia(YSZ)balls at a speed of 300 r/min.The mass ratio of powders,YSZ balls and ethanol were 3.0:5.0:0.8.The ground powder was then dried in an oven for 12 h.The MgO crucible green body was fabricated via cold isostatic pressing at 150 MPa for 3 min.Subsequently,the green body was sintered in a high-temperature silicon molybdenum rod sintering furnace at 1750℃for 6 h.The outer diameter,inner diameter,and height of

关 键 词：坩埚 感应熔炼 镍基高温合金 界面反应 浮渣 

分 类 号：TQ17[化学工程—硅酸盐工业]