Keynote Speaker

Prof. Qibin Liu

Guizhou University

E-mail: qbliu2@263.net

Title:

Composition Design, Laser Preparation and Application of High Entropy Alloy Coating with Strong Acid Erosion Resistance

Profile:

Liu Qibin, male, a member of the Dong ethnic group, holds a Ph.D., and serves as a professor and doctoral supervisor. He is recognized as a core expert in Guizhou Province and is entitled to the special allowance from the State Council. Currently, he is the Dean of the School of Materials and Metallurgy at Guizhou University, a member of the China Democratic League, and a standing committee member of the 10th Guizhou Provincial Committee of the Chinese People's Political Consultative Conference. Dr. Liu obtained his Ph.D. from Dalian University of Technology in June 2005 and completed his postdoctoral research at the National Engineering Research Center for Biomedical Materials at Sichuan University in November 2008. To date, he has published over 200 papers in prestigious academic journals both domestically and internationally, with 80 indexed by "SCI" and more than 120 by "EI." Additionally, he has authored three academic monographs and one national-level planning textbook. Dr. Liu has led more than 60 vertical and horizontal projects, including those funded by the National Natural Science Foundation of China. His research focuses on high-entropy alloy coating materials, laser additive manufacturing, electronic functional ceramics, biomedical ceramics, metal matrix composites, new energy materials, and phosphogypsum.

Abstract:

Agitator blades made of 904 L stainless steel frequently underwent wear and erosion behavior in the phosphoric acid reactor. To improve the erosion resistance of 904 L steel, the composition of [Cr–Fe4Co4Ni4]Cr2.6-xAlxMo0.4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0, at.%) high entropy alloy (HEA) was designed by a cluster-plus-glue-atom model. The HEA coating was fabricated by laser cladding. The experimental results show that the HEA coating has good metallurgical bonding with the substrate. The phase of HEA coatings is mainly composed of FCC solid solution. The microstructure of HEA coatings is a typical dendrite structure. With the addition of Al, the hardness and wear

resistance of HEA coatings are improved gradually. When x = 1.0, the microhardness of the coating can reach 332.6 HV0.2, which is 1.75 times than that of 904 L steel substrate. The wear volume (1.48 mm3 ) of the coating is almost half that of the substrate (2.62 mm3 ). When x = 0.8, the self-corrosion current density of the coating is about one-third of the substrate, and the impedance is increased by 3 times. Under the condition of solid particle erosion, the erosion mechanism of HEA coatings is the mixing of cutting-plowing and crater. Al0.8 coating has good erosion performance with the lowest erosion rate (0.028 mm3 /h).