The microstructure characteristics and strengthening mechanism of Inconel738LC(IN-738LC) alloy prepared by using induction-assisted directed energy deposition(IDED) were elucidated through the investigation of samples...The microstructure characteristics and strengthening mechanism of Inconel738LC(IN-738LC) alloy prepared by using induction-assisted directed energy deposition(IDED) were elucidated through the investigation of samples subjected to IDED under 1050℃ preheating with and without hot isostatic pressing(HIP,1190℃,105 MPa,and 3 h).Results show that the as-deposited sample mainly consisted of epitaxial columnar crystals and inhomogeneously distributed γ’ phases in interdendritic and dendritic core regions.After HIP,grain morphology changed negligibly,whereas the size of the γ’ phase became increasingly even.After further heat treatment(HT,1070℃,2 h + 845℃,24 h),the γ’ phase in the as-deposited and HIPed samples presented a bimodal size distribution,whereas that in the as-deposited sample showed a size that remained uneven.The comparison of tensile properties revealed that the tensile strength and uniform elongation of the HIP + HTed sample increased by 5% and 46%,respectively,due to the synergistic deformation of bimodal γ’phases,especially large cubic γ’ phases.Finally,the relationship between phase transformations and plastic deformations in the IDEDed sample was discussed on the basis of generalized stability theory in terms of the trade-off between thermodynamics and kinetics.展开更多
DZ125 directional solidified superalloys show excellent bearing temperature ability and creep resistance and have been widely used to manufacture the advanced aviation engine blades parts.However,the high temperatures...DZ125 directional solidified superalloys show excellent bearing temperature ability and creep resistance and have been widely used to manufacture the advanced aviation engine blades parts.However,the high temperatures and stresses for longtime service would cause a loss of mechanical properties and service life.In this paper,the damaged alloys were repaired using hot isostatic pressing combined with rejuvenation heat treatment technology,where the irregularγ'phases in damaged alloys are recovered to be cubic particles like original state and the creep cavities and casting porosities also reduce obviously compared with those in damaged state.The restorable alloys exhibit apparently higher tensile properties and hardness than the alloys in damaged state,which is close or even more than those of original alloy,and their elongation and rupture life can satisfy criterion completely.This method can be easily extent to repair other damaged superalloys.展开更多
This paper details the latest situation and features of the technology development in terms of China’s oral care products industry and proposes the following development direction in this sector. Meanwhile, the paper...This paper details the latest situation and features of the technology development in terms of China’s oral care products industry and proposes the following development direction in this sector. Meanwhile, the paper analyzes the popular products in the international market of oral care products and also predicts the trend of the product future in China’s market.展开更多
基金financial support of the National Natural Science Foundation of China(Nos.52130110 and U22A20189)the Research Fund of the State Key Laboratory of Solidification Processing(No.2023-TS-10)。
文摘The microstructure characteristics and strengthening mechanism of Inconel738LC(IN-738LC) alloy prepared by using induction-assisted directed energy deposition(IDED) were elucidated through the investigation of samples subjected to IDED under 1050℃ preheating with and without hot isostatic pressing(HIP,1190℃,105 MPa,and 3 h).Results show that the as-deposited sample mainly consisted of epitaxial columnar crystals and inhomogeneously distributed γ’ phases in interdendritic and dendritic core regions.After HIP,grain morphology changed negligibly,whereas the size of the γ’ phase became increasingly even.After further heat treatment(HT,1070℃,2 h + 845℃,24 h),the γ’ phase in the as-deposited and HIPed samples presented a bimodal size distribution,whereas that in the as-deposited sample showed a size that remained uneven.The comparison of tensile properties revealed that the tensile strength and uniform elongation of the HIP + HTed sample increased by 5% and 46%,respectively,due to the synergistic deformation of bimodal γ’phases,especially large cubic γ’ phases.Finally,the relationship between phase transformations and plastic deformations in the IDEDed sample was discussed on the basis of generalized stability theory in terms of the trade-off between thermodynamics and kinetics.
基金financially supported by the National Key Research and Development Project (No.2016YFC0801900)。
文摘DZ125 directional solidified superalloys show excellent bearing temperature ability and creep resistance and have been widely used to manufacture the advanced aviation engine blades parts.However,the high temperatures and stresses for longtime service would cause a loss of mechanical properties and service life.In this paper,the damaged alloys were repaired using hot isostatic pressing combined with rejuvenation heat treatment technology,where the irregularγ'phases in damaged alloys are recovered to be cubic particles like original state and the creep cavities and casting porosities also reduce obviously compared with those in damaged state.The restorable alloys exhibit apparently higher tensile properties and hardness than the alloys in damaged state,which is close or even more than those of original alloy,and their elongation and rupture life can satisfy criterion completely.This method can be easily extent to repair other damaged superalloys.
文摘This paper details the latest situation and features of the technology development in terms of China’s oral care products industry and proposes the following development direction in this sector. Meanwhile, the paper analyzes the popular products in the international market of oral care products and also predicts the trend of the product future in China’s market.
