Thermal properties of Inconel 625-NbC metal matrix composites (MMC)

[Display omitted] •Good homogenization, dense microstructure, and proper distribution of NbC were achieved in Inconel 625-NbC due to the Spark Plasma Sintering.•Composites up to the 15 wt% of NbC maintained similar Coefficient of Thermal Expansion, Thermal Conductivity and Thermal Diffusivity.•The hot rolling, previously used during the Inconel 625-NbC manufacturing, was discovered not to significantly affect the abovementioned finding.•Only specific heat was reduced in comparison to the referenced Inconel 625 superalloy. Inconel 625-NbC Metal Matrix Composite (MMC) is an emergent material of Inconel 625-carbide composites. It is characterized by dense microstructure, improved hardness, and preserved passive Cr-rich layer formation during oxidation. In this study, its thermal properties were investigated. Inconel 625-NbC composites and Inconel 625 reference alloy were consolidated by Spark Plasma Sintering (SPS). Their microstructure, phase composition, Coefficient of Thermal Expansion (CTE), thermal diffusivity (α), thermal conductivity (λ), and specific heat (cp) were studied. The addition of NbC into Inconel 625 matrix did not significantly affect the CTE or λ of the final composite. Thermal conductivity of Inconel 625-NbC was initially lower than 625 superalloy but was increasing faster in function of temperature. cp functions of SPS-ed 625 alloy and composites had different slopes in comparison to literature. The influence of hot rolling, part of Inconel 625-NbC obtaining SPS technology, was also studied. It affected composites cp.