作　　者： ; ; ; ;

机构地区： 洛阳理工学院

出　　处： 《真空科学与技术学报》 2011年第2期201-207,共7页

摘　　要： 使用X射线衍射分析仪、扫描电镜、电子拉伸试验机、高温金相显微镜研究了在模壳内壁表面的涂层中添加孕育剂铝酸钴和在真空熔铸过程中施加工频旋转电磁搅拌对K417高温合金真空精密铸件凝固组织和性能的影响。结果表明:采用将在真空熔铸过程中施加150 A的工频旋转电磁搅拌和在模壳内壁表面的涂层中添加孕育剂铝酸钴相复合的方法,可以得到晶粒细化至95μm、断面等轴晶比例达到99%的K417高温合金真空精密铸件。当在电磁搅拌和孕育剂作用下将K417高温合金真空精密铸件的晶粒尺寸从3.45 mm细化至95μm,可以使其粗大等轴晶向细小粒状晶转变,(γ+γ')共晶的尺寸减小,室温和650℃中温的拉伸性能得到明显改善。 Here,we addressed the grain refinement in vacuum of the K417 super-alloy in vacuum investment casting by a combination of rotary electromagnetic stirring and adding the inoculants,CoAl2O4,into the surface coating on the solidification mold.The impacts of the electromagnetic stirring and the inoculants on the microstructures and properties of the super-alloy were characterized with X-ray diffraction,scanning electron microscopy,and high temperature metallurgical microscope.The results show that the electromagnetic stirring and the inoculants effectively improve the surface morphologies of the super-alloy.For example,driven at power frequency and a current of 150 A,the stirring and the inoculants resulted in reducing the averaged grain size of the K417 super-alloy to 95 μm,and an increase of the fraction of equiaxed grains of the K417 super-alloy up to 99%.The coarse dendrite structure changed into fine granular grains.The sizes of the（γ＋γ′） eutectic were also reduced,and consequently the tensile property of the K147 super-alloy,at room temperature and 650℃,significantly improved.

关 键 词： 旋转电磁搅拌 孕育剂 高温合金 真空精密铸件 晶粒细化

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]