Invited Speaker
Assoc. Prof. Wenquan Lv
Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences
E-mail: wqlv@licp.cas.cn
Title: “High-end Equipment, Green Manufacturing” Advanced Materials and Modern Surface Engineering
Profile:
Dr. Lv Wenquan is an Associate Researcher at the Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, and a Postdoctoral Researcher at the Institute of Modern Physics, Chinese Academy of Sciences. His research expertise lies in material surface modification, functional ceramic thin films, friction/wear-resistant coatings, corrosion/anti-fouling coatings, and the preparation of micro/nano functional powder materials. With extensive experience in multi-scale toughening design of thin films, microstructure regulation methods, and the development of coating longevity enhancement technologies for harsh environments, Dr. Lv has made significant contributions to both theoretical studies and engineering applications. He has led or participated in over 10 national-level and ministerial/provincial-level projects, including defense industry collaborative projects and technological R&D initiatives. His research addresses critical technical challenges and industrial applications across various sectors, such as nuclear power, defense, wind energy, and precision machining. Dr. Lv has published over 10 peer-reviewed papers in high-impact journals, including Ceramics International and Advanced Materials Interfaces, and holds multiple granted Chinese invention patents for advanced material technologies. His expertise spans from fundamental research to the industrial implementation of advanced coating systems under extreme operational conditions.
Abstract:
For structural metallic materials aiming for high temperature applications, their Cr and Al contents have to be maintained at low levels so as to obtain excellent mechanical properties. As a result, they are incapable to achieve selective oxidation, i.e. thermally grow protective chromia or alumina scales, and the resistance to high temperature oxidation is unsatisfactory. According to theoretical analysis based on classical Wagner’s oxidation theory, the critical Cr content ( ) required for transition of Cr2O3 from internal precipitation to external scaling is lower than that ( ) for sustaining the steady growth of an external Cr2O3 layer. This implies that the alloys with the Cr content lying between and have a marginal capability to from a protective Cr2O3 layer. Based on this finding, we propose a novel concept to “catalyze” the selective oxidation of low Cr alloys relying on their relatively low Cr content, by preparing a Cr precursor film (below 1 μm thick) which can assist the initial establishment of an Cr2O3 layer on the alloy surface. Therefore, the high Cr content threshold required by is overcome, and subsequent steady growth of the formed Cr2O3 layer can be sustained relying the alloys’ relatively low Cr content. Eventually, selective oxidation of Cr can be achieved in low Cr alloys.