The morphology and chemical composition evolution of mullite based refractory inclusions in FGH96 PM superalloy with powder state, hot isostatic pressing (HIP) and hot deformation (HF) were studied by means of artificial implantation of inclusions, optical microscopy (OM), scanning electron microscopy (SEM) and electrolytic etching. The mechanism of interfacial reaction between mullite based refractory inclusions and alloy matrix was revealed. The results show that in the powder state, the artificial mullite based inclusions are irregular particles, and there is no obvious change of morphology and composition in the inclusions after HIP process at high temperature and high pressure. A complex reaction layer is formed at the interface between inclusions and alloy matrix. The reaction layer is consisted of Al and Ti oxides. After thermal deformation of 1080 ℃/0.0004 s-1 under the condition of 25% deformation rate, the main morphology and composition of the inclusions are not changed obviously. The reaction layer coated on the inclusion began to peel and elongate from the inclusion with the deformation of the superalloy matrix, and aggregated on the side close to the elongation direction with the flow deformation of the matrix. When the deformation degree is 50%, mullite inclusions and the externally coated reaction layer are broken and deformed to form an inclusion fragments and reaction layer. The inclusions in the composite form are distributed linearly, and the long axis is perpendicular to the compression direction. When the reaction layer coated outside the inclusion is stripped and the mullite inclusion is broken to form a new surface exposed to the superalloy matrix, the reaction continues to form a new reaction layer. The crushed mullite inclusion is still dominated by O, Al and Si, but it also contains a small amount of element in the superalloy such as Ni, Cr, Ti, Co and Mo.
Interfacial reaction between mullite-based inclusions and PM superalloy FGH96
2022
Article (Journal)
Electronic Resource
Unknown
Metadata by DOAJ is licensed under CC BY-SA 1.0
Effect of Hot Deformation on PPB Precipitations and Microstructure in P/M Superalloy FGH96
DOAJ | 2018
|Effect of Deforming Temperature and Strain on Abnormal Grain Growth of Extruded FGH96 Superalloy
DOAJ | 2016
|Microstructures and Properties of FGH96/DD6 Joints Brazed at Vacuum Pressure State
DOAJ | 2017
|