Precipitation Behavior of Spherical γ′ Phase in Eutectic Area of Ni₃Al‐Based Alloy

Abstract

Understanding and mastering initial status in eutectic area (γ′–γ) of Ni3Al‐based alloy under solution treatment conditions are beneficial to its aging treatment and applications. In this work, optimal solution treatment process parameters of JG4246A Ni3Al‐based alloy are investigated based on microstructure observation, chemical composition analysis, and micro‐hardness test. Results show that the alloy with solution temperature of 1270 °C for 6 h possess smoother eutectic area (γ′–γ) boundaries, more stable carbides, and relatively higher micro‐hardness. More importantly, to clarify the evolution behavior of Ni3Al (γ′) phase in eutectic area (γ′–γ) under solution treatment conditions, short‐time (3 h) and long‐time (18 h) solution treatments at 1270 °C are applied and the evolution behavior is analyzed by TEM. Results show that plenty of spherical Ni3Al (γ′) phase appears in eutectic area (γ′–γ), with its dimensions changing little with solution time increasing. Vacancies, lattice distortion, and thermo‐stress mainly contribut to the precipitation and growth of spherical Ni3Al (γ′) phase.

Effect of Holding Time on Microstructure and Mechanical Properties of Dissimilar γ'‐Strengthened Superalloys TLP Joint

“…ATI 718Plus and polycrystalline Ni 3 Al-based superalloys are both γ' precipitation-strengthened Ni-based superalloys, which are ideal materials for turbine disks and blades in aeroengines, respectively. [4][5][6][7] In practical applications, complex thermal structural components in turbine disks are generally formed by precision investment casting technology and then bonded. Different parts are composed of various high-temperature materials, which can effectively improve engine performance.…”