镍基高温合金CM247LC定向凝固组织的演化研究  

Microstructure Evolution of Directionally Solidified Ni-based CM247LC Superalloy

作　　者：杨叶 徐维台 赵国平[1] YANG Ye;XU Weitai;ZHAO Guoping(School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212000;Shenzhen Wedge Avia-tion Technology Co.,Ltd.,Shenzhen 518000)

机构地区：[1]江苏大学材料科学与工程学院,镇江212000 [2]深圳市万泽航空科技有限责任公司,深圳518000

出　　处：《特种铸造及有色合金》2024年第8期1119-1126,共8页Special Casting & Nonferrous Alloys

摘　　要：采用Bridgman法以2.5 mm/min的抽拉速度制备高温合金CM247LC定向凝固试样,研究定向凝固高度方向上的组织演变。采用体视显微镜(SM)、金相显微镜(OM)、扫描电镜(SEM)、能谱仪(EDS)及JMatPro热力学计算软件、ProCAST铸造模拟软件等对铸态试样组织和性能进行表征和研究。结果表明,柱状晶粒的竞争生长主要发生于距水冷盘60 mm以下的高度范围内;枝晶臂间距的变化主要依赖于轴向温度梯度与生长速度的变化,随距水冷盘距离提升,枝晶臂间距增加的趋势变缓。CM247LC的铸态组织除γ枝晶外,还包括γ/γ'共晶和MC碳化物,其尺寸变化规律与枝晶臂间距一致。Ni-based CM247LC superalloy specimen was directionally solidified using Bridgman method with pulling speed of 2.5 mm/min to investigate the microstructure evolution along solidification direction.The microstructure and performance of as-cast specimen were characterized by stereomicroscope(SM),metallurgical microscope(OM),scanning electron microscope(SEM),energy spectrometer(EDS),as well as thermodynamic calculation software JMatPro and casting simulation software ProCAST.The results indciate that the competitive growth of columnar grains mainly occurs in the range of height below 60 mm from the water-cooling plate.The variation of dendrite arm spacing mainly depends on the axial temperature gradient and variation of growth rate,which gradually slows down with the distance from water-cooling plate increasing.The as-cast microstructure is composed ofγ/γ'eutectic and MC carbides in addtition toγdendrites,of which the size variation law is similar to that of dendrite arm spacing.

关 键 词：镍基高温合金 定向凝固 竞争生长 显微组织 CM247LC 

分 类 号：TG132.32[一般工业技术—材料科学与工程] TG2443[金属学及工艺—合金]