Microstructure of Laser Re-Melted AlCoCrCuFeNi High Entropy Alloy Coatings Produced by Plasma Spraying

Entropy

Tai M. Yue²  Hui Xie²  Xin Lin¹  Haiou Yang¹ 

[1] State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China; E-Mails:;Advanced Manufacturing Technology Research Centre, Department of Industrial and Systems Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong; E-Mails:

关键词: high entropy alloy;    plasma spray;    laser melting;    epitaxial growth;    columnar-to-equiaxed transition;   

DOI  :  10.3390/e15072833

来源: mdpi

【 摘 要 】

An AlCoCrCuFeNi high-entropy alloy (HEA) coating was fabricated on a pure magnesium substrate using a two-step method, involving plasma spray processing and laser re-melting. After laser re-melting, the microporosity present in the as-sprayed coating was eliminated, and a dense surface layer was obtained. The microstructure of the laser-remelted layer exhibits an epitaxial growth of columnar dendrites, which originate from the crystals of the spray coating. The presence of a continuous epitaxial growth of columnar HEA dendrites in the laser re-melted layer was analyzed based on the critical stability condition of a planar interface. The solidification of a columnar dendrite structure of the HEA alloy in the laser-remelted layer was analyzed based on the Kurz–Giovanola–Trivedi model and Hunt’s criterion, with modifications for a multi-component alloy.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.