Improving Mechanical Properties of GH4169 Alloys by Reversing the Deformation and Aging Sequence

Abstract

Herein, the microstructure evolution and mechanical properties of GH4169 alloys obtained by solution treatment-deformation-two-stage aging (SDA) and solution treatment-two-stage aging-deformation (SAD) are investigated. The results show that the density of average geometrically necessary dislocations and the size of γ" precipitates in the SAD sample are larger than that in the SDA sample. The ultimate tensile strength (UTS) of the SAD sample is 1651 AE 24 MPa, which is 171 MPa higher than that of the SDA sample, whereas the fracture elongation of the SAD sample decreases only 3.4%. The significant increment of the UTS in the SAD samples is attributed to the contributions of the dislocation strengthening and precipitation strengthening. SAD processing could be considered as a more effective approach to enhance the mechanical properties of GH4169 alloys.

Effect of Aging Temperature on Precipitates Evolution and Mechanical Properties of GH4169 Superalloy

“…Qin et al [13] found that when the volume fraction was similar, the strength displayed a rising trend with the increase of γ phase size. A similar phenomenon was reported in the study by Ran et al [14]. They quantitatively calculated the contribution of the precipitated phase to the strength and found that the strength change is sensitive to the size of the γ phase.…”

A Theoretical Model for Predicting the Ultimate Strength of Superalloys in a Wide Temperature Range

“…As the modern industry paves the way, many materials are subject to different temperatures in the service environment. [1][2][3] Since their production, nickel-based superalloys have been used mainly in high-temperature environments that can withstand harsh mechanical conditions. [4][5][6][7][8][9] Examples include pressure vessels, nuclear reactors, etc.…”