Abstract: In order to compare the microstructure and high temperature oxidation resistance of Cr-coated Zr-4 alloy prepared by magnetron sputtering and multi-arc ion plating, Cr-coated Zr-4 alloy were prepared by DC magnetron sputtering and multi-arc ion plating, respectively. And the high temperature oxidation resistance was studied in air atmosphere. The results show that the Cr-coated Zr-4 alloy specimen prepared by magnetron sputtering has smooth surface, and the Cr coating grows preferentially along the (211) crystal plane, while there are a lot of droplets on the surface of the Cr-coated Zr-4 alloy specimen prepared by multi-arc ion plating, and the Cr coating grows preferentially along the (110) crystal plane. The results of high-temperature oxidation experiments show that the oxidation mass gain of the Cr-coated Zr-4 alloy specimen prepared by magnetron sputtering is about half of that of the multi-arc ion plating. The oxidized microstructure shows that the specimen prepared by magnetron sputtering still has a residual Cr coating with a thickness of about 4 μm, and the O atoms only diffuse to a distance of about 8 μm from the surface, while the Cr coating of the specimen prepared by multi-arc ion plating was completely oxidized, and a large number of O atoms diffused into the Zr-4 alloy matrix at a depth of about 1 mm from the surface of the specimen. Therefore, the Cr-coated Zr-4 alloy prepared by magnetron sputtering has better high temperature oxidation resistance.

Key words: Cr-coated Zr-4 alloy, high temperature oxidation resistance, microstructure, magnetron sputtering, multi-arc ion plating