Laser powder deposition (LPD) is a very promising repair technique for gas turbine components,which injects the melted powder into the surface of the part and forms the clad with designed geometry.In this paper Fe-Ni-...Laser powder deposition (LPD) is a very promising repair technique for gas turbine components,which injects the melted powder into the surface of the part and forms the clad with designed geometry.In this paper Fe-Ni-Cr powder is deposited by LPD,and heat treatment is subsequently employed for optimizing the microstructure and improving the mechanical properties of the as-deposited clad.The microstructure of the as-deposited clad consists of Nb bearing Laves phase and γ austenite matrix.Strengthening phase γ'' can be precipitated by post heat treatment for increasing the mechanical properties.But the existence of Laves phase weakens the mechanical properties of the clad,even inducing the hot cracking.Unfortunately,DTA results show liquation reaction of Laves phase is as high as 1141 ℃.The solution treatment under 980 ℃ hardly dissolves the Laves phase.It is needed to control the precipitation of Laves phase by further work.展开更多
文摘Laser powder deposition (LPD) is a very promising repair technique for gas turbine components,which injects the melted powder into the surface of the part and forms the clad with designed geometry.In this paper Fe-Ni-Cr powder is deposited by LPD,and heat treatment is subsequently employed for optimizing the microstructure and improving the mechanical properties of the as-deposited clad.The microstructure of the as-deposited clad consists of Nb bearing Laves phase and γ austenite matrix.Strengthening phase γ'' can be precipitated by post heat treatment for increasing the mechanical properties.But the existence of Laves phase weakens the mechanical properties of the clad,even inducing the hot cracking.Unfortunately,DTA results show liquation reaction of Laves phase is as high as 1141 ℃.The solution treatment under 980 ℃ hardly dissolves the Laves phase.It is needed to control the precipitation of Laves phase by further work.
