Open-cell Inconel 625 superalloy foams were prepared by suspension impregnation method which involves replication of pure nickel foam ligaments with a mixed powder suspension and subsequent heat treatments.The objecti...Open-cell Inconel 625 superalloy foams were prepared by suspension impregnation method which involves replication of pure nickel foam ligaments with a mixed powder suspension and subsequent heat treatments.The objective of the present study is to find a suitable method ensuring complete densification of the superalloy foam ligaments without using low-melting additives and achieving uniform chemical composition at moderate sintering temperatures.Foams prepared using the above methodology were evaluated for the microstructure and compositional variation across the foam ligaments by scanning electron microscopy(SEM)coupled with electron dispersive spectroscopy(EDS).Quasi-static compressive properties of the foams were evaluated.It is shown that if elemental powders of Cr,Mo and Ni are used as additives to the superalloy powder suspension,high ligament density with uniform chemical composition conforming to the Inconel 625 specification is achieved at moderate sintering temperatures.These results are attributed to the formation of low melting eutectics and to acceleration of the diffusion kinetics due to the non-equilibrium thermodynamic conditions created by large compositional gradients in the presence of elemental powders.展开更多
The Ce/Cr coating was homogenously deposited onto the reticulated open-cell Ni?Cr?Fe alloy foam by the pack cementation process.The mechanical properties of the Ce/Cr coated alloy foams were investigated by the quasi-...The Ce/Cr coating was homogenously deposited onto the reticulated open-cell Ni?Cr?Fe alloy foam by the pack cementation process.The mechanical properties of the Ce/Cr coated alloy foams were investigated by the quasi-static compression test.Simultaneously,the deformation and failure mechanisms of Ce/Cr coated alloy foams were discussed.The results show that the adding amount of CeO2powders influences the mechanical properties of the Ce/Cr coated alloy foams.Despite an increase in density as compared to the uncoated foams,the Ce/Cr coated foams exhibit improvement in both yield strength and energy-absorption performance.Especially,the energy-absorption performance of2%Ce/Cr(mass fraction)coated alloy foam is averagely1.9times as high as that of the bare Ni?Cr?Fe alloy foam.In addition,the mechanical properties of the Ce/Cr coated alloy foams increase with the increase of strain rate.The distortion and cracking are mainly the deformation behavior of the Ce/Cr coated alloy foam,confirmed by SEM images.展开更多
基金financial support from DMRL,India(No.7196-22)Belarusian Republican Foundation for Fundamental Researches(No.T20R-049)Russian Foundation for basic Research(No.20-53-00009-Bel)。
文摘Open-cell Inconel 625 superalloy foams were prepared by suspension impregnation method which involves replication of pure nickel foam ligaments with a mixed powder suspension and subsequent heat treatments.The objective of the present study is to find a suitable method ensuring complete densification of the superalloy foam ligaments without using low-melting additives and achieving uniform chemical composition at moderate sintering temperatures.Foams prepared using the above methodology were evaluated for the microstructure and compositional variation across the foam ligaments by scanning electron microscopy(SEM)coupled with electron dispersive spectroscopy(EDS).Quasi-static compressive properties of the foams were evaluated.It is shown that if elemental powders of Cr,Mo and Ni are used as additives to the superalloy powder suspension,high ligament density with uniform chemical composition conforming to the Inconel 625 specification is achieved at moderate sintering temperatures.These results are attributed to the formation of low melting eutectics and to acceleration of the diffusion kinetics due to the non-equilibrium thermodynamic conditions created by large compositional gradients in the presence of elemental powders.
基金Project(51501133)supported by the National Natural Science Foundation of ChinaProject(T201629)supported by the Universities of Hubei Province Outstanding Young Scientific and Technological Innovation Team Plans,ChinaProject(AWJ-M16-11)supported by the State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,China
文摘The Ce/Cr coating was homogenously deposited onto the reticulated open-cell Ni?Cr?Fe alloy foam by the pack cementation process.The mechanical properties of the Ce/Cr coated alloy foams were investigated by the quasi-static compression test.Simultaneously,the deformation and failure mechanisms of Ce/Cr coated alloy foams were discussed.The results show that the adding amount of CeO2powders influences the mechanical properties of the Ce/Cr coated alloy foams.Despite an increase in density as compared to the uncoated foams,the Ce/Cr coated foams exhibit improvement in both yield strength and energy-absorption performance.Especially,the energy-absorption performance of2%Ce/Cr(mass fraction)coated alloy foam is averagely1.9times as high as that of the bare Ni?Cr?Fe alloy foam.In addition,the mechanical properties of the Ce/Cr coated alloy foams increase with the increase of strain rate.The distortion and cracking are mainly the deformation behavior of the Ce/Cr coated alloy foam,confirmed by SEM images.
