Measurement and estimation of thermophysical properties of nickel based superalloys

TLDR

The authors measured heat capacity, enthalpy, thermal expansion, density, thermal diffusivity, viscosity, and surface tension of several Ni‑based superalloys, then derived composition‑based relations to calculate these properties and developed additional models to estimate viscosities and surface tensions. Measured thermophysical properties of CMSX‑4, CMSX‑10, CM186LC, IN 738, and Rene 80 revealed that the γ′ (Ni₃Al) phase influences Cp, enthalpy, electrical resistivity, thermal diffusivity, and conductivity, and the authors identified relationships between γ′ content and these properties, with predictions agreeing well with the measurements.

Abstract

Thermophysical properties for the solid and liquid phases of several Ni based superalloys (CMSX-4, CMSX-10, CM186LC, IN 738 and Rene 80) have been measured. The following properties were measured: heat capacity and enthalpy, thermal expansion coefficient and density, thermal diffusivity, viscosity and surface tension. Analysis of these measurements showed that that γ′ phase (Ni 3 Al) affected the values for the following properties; C p , enthalpy, electrical resistivity, thermal diffusivity and conductivity. Relationships have been identified between properties and the γ′ phase content (which can be represented by mass% Al in the alloy). These relations were then used to calculate property values of the alloys from chemical composition. Other relations were developed to estimate the viscosities and surface tensions of Ni based superalloys. The predicted property values were found to be in good agreement with the measured values.