Effect of bias voltage on the microstructure and high‐temperature steam oxidation behavior of Cr coatings prepared by multi‐arc plating on Zircaloy‐4 alloy

Abstract Cr coatings were deposited on the Zircaloy‐4 alloy by multi‐arc ion plating under different bias voltages from −50 to −110 V, and the microstructure, mechanical properties, and high‐temperature steam oxidation behavior of these coatings were systematically investigated. The results indicate that the bias voltage significantly affects the crystal orientation, surface morphology, deposition rate, nanohardness, and bonding strength of Cr coating on the Zircaloy‐4 alloy. The high‐temperature oxidation behavior of the Cr coating is closely related to its crystallographic orientation. Compared with the Cr coating with relatively random grain orientations, the Cr coating with (211) preferred orientation has a dense and uniform oxide scale and has the best oxidation resistance in the steam environment at 1200°C.