Investigation of room temperature strengthening mechanism on PM Ni-base superalloys with tantalum addition

In this paper, the mechanical properties of the high-performance powder metallurgy (PM) superalloys with Ta addition fabricated by the Central Iron and Steel Research Institute (CISRI) were evaluated at room temperature (RT). We focus on the reason why the solute element Ta affects RT properties of PM superalloys. To this end, the necessary advanced characterization methods were used to study the plastic deformation and fracture mecha-nisms. The results revealed that the leading cause for the enhancement in RT yield strength with Ta increasing is the antiphase boundary (APB) strengthening of the bimodal gamma' precipitates, the extended stacking fault (ESF) shear and the interaction between ESF and dislocation. Importantly, the microtwin structure was found in the deformed substructure, which is an extraordinary phenomenon in RT plastic deformation for PM superalloys.

Automated summary

This paper evaluates the mechanical properties of high-performance PM superalloys with Ta addition fabricated by CISRI at room temperature. The study focuses on how the solute element Ta affects the properties of the alloys, utilizing advanced characterization methods to investigate plastic deformation and fracture mechanisms. The results highlight the strengthening effects of APB, ESF, and microtwin structures on the RT yield strength of the PM superalloys.