Effect of Si on the Solidification Segregation Behavior of a New Ni–Co‐Based Superalloy

Abstract

Herein, the effects of Si addition on the microstructure and solidification behavior of a new Ni–Co‐based superalloy are investigated. The microstructure of the as‐cast alloys is mainly composed of γ, γ′, (γ–γ′) eutectics, and MC‐type carbides. The results demonstrate that Si addition significantly decreases the size and volume fraction of (γ–γ′) eutectics, while promoting the formation of Si‐rich phase precipitated in front of the (γ–γ′) eutectics. The formation of a Si‐rich phase is induced by the rejection of Ti and Si into the residual liquid during the γ matrix formation. With the increase in Si content, the size distribution of (γ–γ′) eutectics decreases due to the formation of the Si‐rich phase consuming the forming element of (γ–γ′) eutectics. The solidus and liquidus temperatures of the alloy decrease with the increase in Si. However, the range of melting temperature increases. The Si addition promotes the segregation of alloying elements, and Si tends to segregate in the interdendritic region.

Effect of Co Content and Temperature on Shear Mechanical Properties of Nano‐Polycrystalline Ni–Co Alloy

“…It is widely used in aerospace, energy, petrochemical industry or special electronics, optoelectronics, and other fields. It is also called “super‐alloy“ [ 1,2 ] because of its good fatigue performance, fracture toughness, and other comprehensive properties. To study the macroscopic deformation mechanism and mechanical properties of nickel–cobalt alloys, many scholars have carried out a series of experiments in the form of experiments.…”