Microstructure and corrosion properties of FeCoNiCrMn high entropy alloy coatings prepared by high speed laser cladding and ultrasonic surface mechanical rolling treatment

• Published in: Materials letters Vol. 259; p. 126769
• Main Authors: Cui, Zeqin, Qin, Zhen, Dong, Peng, Mi, Yunjun, Gong, Dianqing, Li, Weiguo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.01.2020; Elsevier BV
• Subjects: Columnar structure; Compressive properties; Corrosion; Corrosion mechanisms; Corrosion prevention; Corrosion resistance; Corrosion resistant alloys; Crystal structure; Grain boundaries; Grain refinement; High entropy alloys; High-entropy alloy coating; High-speed laser cladding; Laser beam cladding; Materials science; Microstructure; Phase transitions; Protective coatings; Residual stress; Ultrasonic surface mechanical rolling treatment; Wetting; High-entropy alloy coating; Ultrasonic surface mechanical rolling treatment; High-speed laser cladding; Corrosion; Microstructure
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2019.126769

•FeCoNiCrMn coating was prepared by combining HSLC and SMRT techniques.•The changes in the microstructure and composition of the coating were analyzed.•Surface gradient structure was formed in the high-entropy alloy by SMRT.•Role of surface gradient structure in improving corrosion resistance was discussed. The FeCoNiCrMn high-entropy alloy (HEA) coatings were prepared by high-speed laser cladding (HSLC) technology, and the surface was subjected to ultrasonic surface mechanical rolling treatment (SMRT). After SMRT, the surface of the coatings show a gradient structure. The coatings consist of planar crystal, columnar dendrites and equiaxed crystals from inside to outside. Corrosion behavior in a 3.5% NaCl solution indicates that SMRTed coatings exhibit higher corrosion resistance than the coatings without SMRT. Anti-corrosion mechanism was discussed based on grain refinement, grain boundary wetting phase transitions and compressive residual stress.