学术报告1：Mechanical Reliability Assessment of Brittle Ceramic Components
时间：2015年5月24日（周日）上午（09:00-11:00）
地点：科学园C3栋特陶所417
Brittle ceramics have been widely used in various forms of components that can be found in commercial devices/products of our daily uses. These ceramic components are often found in applications related to energy, electronics, chemical, and environmental industries. In these applications the brittle ceramics need to perform certain functionalities such as transport of electricity, chemical ionic species, heat, and also support of mechanical and thermal stresses during the operations. Tremendous research efforts have placed on the identification and optimization of specific engineering ceramics to achieve those stated functional properties. However, as other material constituents are incorporated into the system targeting a specific purpose, it is necessary to evaluate the mechanical properties of these brittle ceramics and its design to achieve the desired long-term reliability and durability. Many researches carried out often focused only on optimizing and improving their functional properties, while neglecting some key issues related to the mechanical reliability. The mechanical reliability of ceramic components is often dictated by the stress states generated during operations, and the magnitudes of stress are strongly dependent upon material’s physical and mechanical properties, design geometry, and application conditions. In some cases stress could also be generated due to the presence of a chemical gradient in the ceramics, which could lead to large stresses being generated in the component. In addition, ceramics due to its intrinsic brittle nature are typically susceptible to slow crack growth initiated from processing and/or machining defects, potentially resulting in catastrophic failure under the service conditions. In this lecture the mechanical reliability of brittle ceramics used in hot-section structural components and power electronics will be reviewed. Issues encountered during system design and application, and strategies employed to mitigate the stress states and thus enhance the reliability of components will be presented and discussed.
学术报告2：Development of Environmental Barrier Coatings for Hot Section Si-based Ceramic Components
时间：2015年5月25日（周一）上午 （9:00-11:00）
地点：材料楼322室
Advanced silicon-based ceramics as well as oxide-based composites are currently employed for hot-section component applications in gas turbine engines due to their superior high-temperature mechanical performance and oxidation resistance. However, these Si-based and alumina-based ceramic composite components experienced substantial material recession after field service in gas turbines. The material recession resulted from the volatilization of the normally protective silica layer formed due to oxidation reaction or the silica constituent in the oxide-based system. The progressive material recession would eventually lead to dimensional instability and mechanical property degradation, and thus limit the long-term reliability and performance of engines. Hence, an environmental barrier coating (EBC) system, which can effectively protect Si-based and oxide-based ceramic components from gas turbine environments, is critically needed to warrant the projected lifetime durability. Also, the EBC system employed sometime can serve as the thermal management layer to substantially reduce the substrate temperature and maintain the material stability. Environmental barrier coating systems based on rare-earth disilicates as well as oxide-based systems have been developed and engineered to protect Si-based as well as alumina-based ceramic substrate in combustion environments. This lecture reviews the concepts behind the engineering approaches of EBC systems developed. The findings and stability issue of these EBC systems evaluated by a steam-jet technique will be presented and discussed.
学术报告3：Advanced Ceramics for Clean and Efficient Energy Technologies
时间：2015年5月26日（周二）上午（09:00-11:00）
地点：科学园C3栋特陶所417
It is forecasted that the total global energy consumption will increase 49% from 2007 to 2035 based on the data published by Energy Information Administration of US Department of Energy. The key driving forces pushing the increase in worldwide demand are mainly due to 1) industrialization in emerging markets, 2) strong economic growth in emerging market, especially in China and India, 3) globalization, and 4) concerns over energy security. It is realized that the use of natural gas and coal will continue to grow, but there is an imminent need for alternative energy resources to meet the fastest growing demand such as renewable energy as well as other potential resources. This need has now created tremendous new markets. Technologies developed for solar panels, wind turbine, and energy storage are now well established, but others, such as energy harvesting, remain niche while the technology is still being developed. All offer significant business opportunities: energy harvesting, for example, is forecast to be worth $4.4 billion by 2020. However, most renewable energy technologies cannot compete economically with fossil fuels. This lecture will review how emerging ceramic technologies would help to improve manufacturing and energy generation efficiency and bring renewable energy production closer to reality. In addition, the employment of advanced ceramics to improve the gas turbine efficiency as well as for next generation nuclear reactors will be reviewed and discussed in this lecture as well.
附：报告人简介