Creep Behavior and Mechanism of a Re/Ru-containing Nickel-based Single Crystal Superalloy
The effect of solution temperature and the relevant microstructure evolution on the creep behavior of a Re/Ru-containing nickel-based single crystal alloy was assessed,aiming to reveal the effect of the addition of high metlting point elements on the performance of the alloy.The results show that the residual eutectic is still persisted in the inter-dendritic region of the alloy after solution treated at 1328℃;after the residual eutectic was eliminated by solution treated at 1332℃,the creep lifetime of alloy may be enhanced from 321 h to 476 h at 1100℃/140 MPa.The γ'phase in the alloy was changed into rafted structure in the primary period of creep.In the late creep period,although the formed dislocation locks in y'rafts may impede the dislocations movement to enhance the creep resistance of the alloy,the alternat-ed gliding of dislocations causes the tortuosity of γ/γ'rafts to form sub-grains,which in turn may reduce the strength and creep resistance of the alloy.Especially,the reversed microstructure evolution of the raft-ed γ'phase transformed into the block-like configuration may accelerate the strain rate of the alloy until fracture,which is thought to be the deformed and damaged features of the alloy in the later creep period.While the cause of the creep lifetime at 1140℃ being decreased to a great extent is attributed to the γ'phase dissolved to diminish its size and volume fraction.
metallic materialssingle crystal Ni-based alloyRe/Rusolution temperaturecreep dam-agereversed evolution of microstructure
万方数据
维普
