Excellent Double-Aging Strengthening Effect with the High Density γ’ Phase of 945A Nickel-Based Alloy

Abstract

The double-aging strengthening effect of the γ’ phase in 945A nickel-based alloy was investigated. The double-aging treatment significantly improved the compressive yield stress. The sample after 8 h aging at 725 °C and 96 h at 800 °C exhibited the highest compressive yield stress of 1007 MPa, which greatly exceeded the original state of 229 MPa. The strengthening mechanism is mainly attributed to the Orowan strengthening mechanism. After double-aging treatment, high density γ’ phase precipitate was formed, which effectively improves the strength. The precipitate behavior and the strengthening mechanism of γ’ phase precipitates were clarified in detail.