Ultrafast solution treatment to improve the comprehensive mechanical properties of superalloy by pulsed electric current

The traditional solution (1120 degrees C/4 h) and aging (845-1080 degrees C/24 h) processes are the keys for K417G superalloy to obtain the expected microstructure and ensure excellent mechanical properties. It is found here that the investigated microstructure can be achieved by electropulsing solution treatment at 1000 degrees C, and the processing time is 10 minutes. Meanwhile, the morphology of the harmful gamma/gamma' eutectic phase can be quickly modified during the pulsed process, thereby the crack propagation near the eutectic phase changes from a direct pass to a zig-zag pass, which is beneficial to performance improvement. The theoretical analysis and calculation results show that high current density area existed between the heterogeneous phases and the system thermodynamic barrier reduction are the fundamental reasons for the primary gamma' dissolution and the gamma/gamma' eutectic morphology evolution. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

The traditional solution and aging processes are key for achieving expected microstructure and excellent mechanical properties in K417G superalloy. Electropulsing solution treatment at 1000 degrees C for 10 minutes can achieve the desired microstructure and modify the harmful gamma/gamma' eutectic phase morphology, improving performance. The primary reasons for these changes are high current density areas between heterogeneous phases and a reduction in system thermodynamic barrier.