Electrochemical Corrosion and High-Temperature Oxidation Behaviors of Three-dimensionally Interconnected Hexagonal Boron Nitride Reinforced CuNi composite.

The properties of hexagonal boron nitride (hBN) were explored to improve the chemical and thermal performance of a three-dimensionally interconnected hBN (3Di-hBN)-reinforced Cu0.7–Ni0.3 (3Di-hBN CuNi) composite, prepared via a simple two-step process. The chemical performance was examined by potentiodynamic polarization and electrochemical impedance spectroscopy, whereas the thermal performance was investigated by thermogravimetric analysis and high-temperature oxidation experiments. The 3Di-hBN CuNi composite exhibited a corrosion resistance six times higher than that of a powder metallurgy (PM) CuNi alloy (without hBN). Furthermore, during high-temperature oxidation experiments at 900 °C, the 3Di-hBN CuNi composite gained ~ 36% less mass than the PM CuNi alloy, indicating its superior high-temperature oxidation resistance. The improved chemical and thermal stability of the 3Di-hBN CuNi composite were attributed to the impermeability and thermal stability of hBN, that is, its ability to obstruct the penetration and diffusion of atoms, ions, and molecules at high temperatures. [ABSTRACT FROM AUTHOR]