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MMMB Research Seminar
March 21, 2019 @ 11:00 am - 12:30 pm
Hard yet tough nitride-based coatings with anti-bacterial and crack self-healing behaviors
Professor Liping Wang
Key Laboratory of Marine Materials and Related Technologies, Chinese Academy of Sciences
The motivation of this study is to develop and evaluate ceramic coatings, which appear to be the promising solid lubrication and excellent wear resistance at wide temperature range from room temperature to 800 °C. At the same time, the coatings have a long effect anti-bacterial and crack self-healing action. The nitride ceramic coatings incorporated with Ag were prepared by arc ion plating at 400 °C. The hard yes tough coatings with a unique shell-like structure have composed of the discontinuous Ag layer and super hard nitride layer alternately. The ceramic coatings have a thickness of 2-3 m and hardness of about 40 GPa. The uniaxial micropillar compression tests were carried out to identify the fracture strength, and the result shows the coatings have high fracture strength of 14 GPa. The friction coefﬁcient of the coatings is relatively low, and it is about 0.15 at room temperature and 0.2 at 650 °C, respectively. It is found the coatings have a good crack self-healing properties by annealing treatment. The mechanism of silver assisted healing of the coatings was revealed by TEM analysis and simulation method. The Ag nanoparticles (AgNPs) would release from the coating by ‘micro-channel’ and the release rate is determined by the microstructure of the coating. The coatings can release AgNPs at a low concentration and have an excellent anti-bacterial activity.
Prof. Liping Wang is now the director of Key Laboratory of Marine Materials and Related Technologies, in Chinese Academy of Sciences, and group leader of advanced marine materials and environmental behaviors. He devoted in the research of surface engineering with designed functions, particularly for anti-corrosion and anti-wear purpose. During his academic career period, he received Ten-Thousand Talents Program, The National Science Fund for Distinguished Young Scholars,Excellent Training Program for Youth Scientists from Chinese Academy of Sciences, Talented Youth Program and Distinguished Young Scholars from the National Natural Science Foundation of China. Dr. Wang published 150 SCI papers with 5000 total citations in materials surface and interfaces research fields and hold over 40 patents in low-frictions films and anti-corrosion coatings. His research achievement won the 2016 National Technology Invention Award (Rank 1) for his outstanding research work low friction films, working collaboratively with number of high-tech companies and defence departments.