Surface Structure Evolution of Nickel-Based Alloys in Harsh Marine Environment: Theoretical Calculation and Experimental Verification

Keke Chang
Key Laboratory of Marine Materials and Related Technologies, Ningbo Institute of Material
Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 

EXTENDED ABSTRACT: Nickel-based alloys exhibit excellent mechanical properties, oxidation resistance and corrosion resistance, and are therefore widely used in aerospace equipment. However, when the alloys represented by NiCrAlY are in service in harsh marine environments, the continuous oxide protective film on the surface is destroyed, leading to a serious reduction in engine life. Therefore, the development of new nickel-based alloy systems and the evolution of their surface structures are of great significance. Based on the phase diagram, new NiSiAlY system was designed for nickel-based alloys in harsh marine environments. Through multi-scale theoretical calculations and key experiments, the evolution of the surface structure of the alloys was revealed before and after oxidation or corrosion. The oxidation results indicated that the higher the Si content in the alloy, the thinner the outer layer of NiO and the inner layer of oxidation; the corrosion results showed that: The introduction of Si caused the formation of SiO2 on the corrosion alloy surface and reduced the potential difference between γ'γ and Ni5Y. Therefore, through the addition of appropriate elements and composition optimization, the surface structure control of nickel-based alloys for harsh marine service can be regulated, thus further enhancing the oxidation resistance and corrosion resistance of the alloys.

Keywords: Nickel-based alloy; NiSiAlY; Oxidation and Corrosion; Multi-scale Theoretical Calculations

[1] K Xu, K Chang, Y Du, L Wang, J. Mater. Sci. Technol. 88 (2021) 66-78.
[2] K. Xu, K. Chang, M. Yu, D. Zhou, Y. Du, L. Wang, J. Mater. Sci. Technol. 89 (2021)186-198.

Brief Introduction of Speaker
Keke Chang

Keke Chang, Professor at Ningbo Institute of Materials Technology and Engineering(NIMTE), Chinese Academy of Sciences (CAS). He obtained his Bachelor and Master Degree at Central South University, China in 2008 and 2010, respectively; and Doctor Degree from RWTH Aachen University, Germany, in 2013. He is committed to coupling damage, theoretical design and application verification of materials serving in harsh environments such as aviation, marine, nuclear power, etc He has published> 80 papers in SCI journals (such as Sci. Adv., Acta Mater., Adv. Sci.), which were cited> 2200 times. He hosts national-level projects such as Outstanding Young Scholars Fund of National Natural Science Foundation of China and Gem记n National Science Foundation (DFG). His research paper won the "Spriggs Phase Equilibrium Award" of the American Ceramic Society in 2021 (only one in the world). He has won the "Larry Kaufmann Scholarship" of the CALPHAD Committee, "DFG Nachwuchsakademie" of the DFG, and the 10th "Wen Shizhu Maple Leaf Award - Outstanding Young Scholar Award".