Morphological characteristics of the intermetallic phase of heat resisting nickel alloys

Abstract

The paper discusses the main stages of the automatic quantitative analysis of parameters of the'-dispersed phase in high-temperature polycrystalline nickel alloys and indicates their main difference from the standard methods of analyzing disconnected phases. We present 4 classes of characteristics of dispersed phase particles. These characteristics include the volume fraction, the dimensional parameters of particles and the spatial distribution parameters. For example, we calculated the parameters of the '-phase of a blade made of a heat resisting nickel alloy In792. The volume fraction and the equivalent diameter of the '-phase disperse particles increase in operation while their concentration decreases. These parameters of the '-phase change with changes in the mechanical properties of the alloy. The shape of the particles and the scatter of '-phase concentration change little in the process of operation.

Application of the complex parameter of strength and ductility to assess the state of the blades’ material at different periods of operation

“…It should be noted that the choice of recovery heat treatment modes to achieve the optimal shape, size and distribution of particles of the hardening phase does not always lead to an improvement in mechanical properties. The formation of Me6C carbide particles of an unfavorable lamellar form during homogenization at a temperature of 1210°С and further cooling practically eliminates the improvement of properties by controlling the structure of the γ'-phase [4,5,6].…”