Invited Speaker

Assoc. Prof. Zhenya Zhang

Anhui University of Technology

E-mail: zzhenya@ahut.edu.cn

Title: Development of Novel Environmental Barrier Coatings for SiC-based Ceramics to Enable Temperatures above 1450°C

Profile:

Zhang Zhenya, Associate Prof., PhD/postdoctoral, graduated from the Korea Institute of Materials Science and National Changwon University in South Korea. Mainly engaged in research on the design, preparation, and critical service performance evaluation of thermal/environmental barrier coatings and high-temperature protective coating systems in extremely harsh environments. The Ministry of Education has introduced high-level talents from overseas, including Anhui Province's C-class high-end talents and ISO TC 107 registered experts. Hosted/participated in national key research and development programs, National Natural Science Foundation of China, postdoctoral special grants/general grants, provincial and ministerial level funds, major industry university research projects, etc. Published more than 30 papers in academic journals such as Corrosion Science. Authorized and applied for nearly 10 patents, proposed 3 international standards, and won scientific and technological awards such as the Provincial Science and Technology Progress Award.

Abstract:

Environmental barrier coating (EBC) has been developed to protect SiC-based ceramics exposed to harsh environments, such as air and steam conditions. The conventional EBCs are composed of the Si bond coat and rare earth disilicate topcoat layers. However, as the operating temperature of advanced gas turbines typically exceeds 1400 °C, it has been required to replace conventional Si bond coat in EBC with materials possessing higher thermal stability. The HfO2-SiO2 was developed as the novel bond coat deposited on SiC substrate using atmospheric plasma spray in EBC, and the service temperature of EBC was improved to 1475 °C. Furthermore, novel YxYb(2-x)Si2O7 (x = 0.3, 0.5, 0.8, and 1.0) topcoat layer were deposited using atmospheric plasma spray as the topcoat layer in EBC to reduce the thermal conductivity in EBC. The novel EBC of HfO2-SiO2/YxYb(2-x)Si2O7¬ was conducted in air and steam conditions at 1475 °C for various times. The results showed that the novel EBC could effectively reduce the oxidation of EBC-coated SiC and improve the service temperature of EBC in air and steam conditions, which is a promising candidate for the next generation of EBC.

Keywords: Environmental barrier coating; Atmospheric plasma spray; Service temperature; Oxidation.