摘要
研究了1600℃温度下Al_(2)O_(3)、CaO、MgO、Y_(2)O_(3)稳定ZrO_(2)、CaO稳定ZrO_(2)和Y_(2)O_(3)共6种材料坩埚与镍基高温合金K417G熔体的界面反应。结果表明:熔体对Al_(2)O_(3)坩埚以物理侵蚀为主,但坩埚易剥落导致合金中含有Al_(2)O_(3)夹杂物;CaO坩埚与合金界面处生成了液相Ca_(3)Al_(2)O_(6),促进熔体与CaO之间的润湿性,导致界面处粘连严重;MgO坩埚与熔体中Al反应生成MgAl_(2)O_(4)并进入合金生成夹杂物;Y_(2)O_(3)稳定ZrO_(2)坩埚与合金界面处生成Al_(2)O_(3)反应层,但是Al_(2)O_(3)层未对坩埚发生侵蚀,可见这种坩埚具有较强的抗Al_(2)O_(3)渣的能力;CaO稳定ZrO_(2)坩埚与合金界面处生成液相CaAl_(2)O_(4),导致坩埚失稳,向合金内剥落溶解;Y_(2)O_(3)坩埚与合金界面处主要生成Al_(2)Y_(4)O_(9)反应层,并且Y_(2)O_(3)向合金内溶解较为严重。坩埚和熔体交互作用对K417G熔体杂质O含量有显著影响,CaO、Y_(2)O_(3)和Y_(2)O_(3)稳定ZrO_(2)坩埚熔炼合金中O含量没有增加,而CaO稳定ZrO_(2)坩埚熔炼后O含量由0.0007%(质量分数)增加至0.0011%,MgO和Al_(2)O_(3)坩埚熔炼后,合金O含量增加明显,由0.0007%分别增加至0.0034%和0.0135%。
High-performance nickel-based superalloys are highly desired in the aerospace industry.A drawback of vacuum induction melting for processing nickel-based superalloys is that oxide refractories contaminate the molten alloy through crucible-melt interaction.Therefore,crucibles used for producing nickel-based superalloys should be carefully selected to avoid melt contamination.In this study,the interfacial reaction between a molten nickel-based superalloy(K417G)and various oxide refractories,including Al_(2)O_(3),CaO,MgO,ZrO_(2)+12%Y_(2)O_(3)(mass fraction)(Y-PSZ),ZrO_(2)+20%CaO(CSZ),and Y_(2)O_(3),formed by cold isostatic pressing was investigated at 1600℃ by XRD,SEM,and EDS.The effects of the oxide crucibles on the impurity contents of K417G were also evaluated.The results show that physical erosion is the primary mechanism of the interaction between Al_(2)O_(3) crucibles and alloy melt.The readily detached Al_(2)O_(3) particles formed inclusions in the alloy.The Ca_(3)Al_(2)O_(6) liquid phase generated at the melt-crucible interface promoted wettability between the alloy and CaO crucible,resulting in a high adhesion at the interface.The reaction of the MgO crucible with Al in the alloy resulted in the formation of MgAl_(2)O_(4) at the meltcrucible interface,which subsequently entered the alloy to form inclusions.Al_(2)O_(3) was generated at the YPSZ-crucible-alloy interface.However,there was no corrosion of Al_(2)O_(3) in the Y-PSZ crucible,indicating the crucible exhibits excellent corrosion resistance to Al_(2)O_(3) slags.The interaction between the CSZ crucible and alloy melt generated a CaAl_(2)O_(4) liquid phase,making the crucible unstable to dissolve into the alloy.An Al_(2)Y_(4)O_(9) reaction layer is mainly formed at the Y_(2)O_(3)-crucible-alloy interface.The dissolution of Y_(2)O_(3) into the alloy melt was high compared to that of other oxide refractories.The melt-crucible interaction also significantly affected the oxygen content of K417G.The oxygen concentration of the alloy fused by CaO,Y_(2)O_(3
作者
宋庆忠
潜坤
舒磊
陈波
马颖澈
刘奎
SONG Qingzhong;QIAN Kun;SHU Lei;CHEN Bo;MAYingche;LIU Kui(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Metallurgy,Northeastern University,Shenyang 110819,China;Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第7期868-882,共15页
Acta Metallurgica Sinica
