1. Microstructure dependence of electrochemical corrosion resistance for rapidly solidified Ti50Al48Mo2 alloy.
- Author
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Sun, Chonghao, Xiao, Ruilin, Liu, Kelun, Ruan, Ying, and Wei, Bingbo
- Subjects
CORROSION resistance ,MICROSTRUCTURE ,PITTING corrosion ,ELECTROLYTIC corrosion ,ALLOYS ,CORROSION in alloys ,LIQUID alloys - Abstract
• Microstructure and solutes distribution of rapidly solidified Ti 50 Al 48 Mo 2 alloy was investigated. • Passivation film characteristics and forming mechanism of Ti 50 Al 48 Mo 2 alloy at different undercoolings were discussed. • Homogeneous solute distribution improved corrosion resistance of rapidly solidified Ti 50 Al 48 Mo 2 alloy. The rapid solidification of undercooled liquid Ti 50 Al 48 Mo 2 alloy was achieved by the electromagnetic levitation (EML) technique. At small and medium undercoolings, primary (βTi) dendrite reacted with surrounding liquid to drive a peritectic transformation into the (α Ti) phase. The solutal Mo and Al segregations were located within the dendrite center and the grain boundary during peritectic transformation, consequently B2 phase in the dendrite center and γ phase at the grain boundary formed. Once undercooling exceeded 253 K, the peritectic transformation was completely inhibited, and the formation of the B2 phase and γ phase was completely suppressed. The ultrafine eutectoid structure was formed and a complete solute trapping effect was realized. Homogeneous solute distribution facilitated the formation of thicker passivation film with lower defect density and higher film resistance on the alloy surface. Moreover, this weakened micro-galvanic effect reduced the susceptibility to pitting corrosion, and consequently the corrosion resistance of the alloy was improved. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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