Microstructure and Oxidation Resistance of Cr–Al–Si Alloys for High-Temperature Applications

• Main Authors: Jeong-Min Kim, Chae-Young Kim
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Coatings
• Subjects: high temperature; metal coating; Cr–Al–Si, microstructure
• Online Access: https://www.mdpi.com/2079-6412/10/4/329

Cr–Al alloys are attracting much attention as heat- and corrosion-resistant coating materials due to their excellent high-temperature properties. In order to investigate the effect of aluminum content on the microstructure and oxidation resistance of Cr–Al–Si alloys, cast specimens were prepared by using a vacuum-arc melting furnace, and high-temperature oxidation tests were conducted with the specimens, for 1 h, at 1100 °C, in air. In the case of cast microstructure of Cr–Al–Si alloys, it consists mainly of Cr single phase, up to 5 at.% Al, and AlCr phases were additionally formed in alloys containing 10% Al or more. In the specimen with 20% Al added, CrSi phase was also found in addition to the AlCr phase. The weight change of the specimens heated for 1 h, at 1100 °C, indicated that all had excellent oxidation resistance. However, when the Al content was less than 10%, the weight gain tended to be a little lower than that of 10% or more.