学术报告通知

应哈工大特陶所王玉金教授的邀请，美国密苏里罗拉理工大学William G. Fahrenholtz教授将于2016年5月23日来我校访问并作学术报告，欢迎全校师生参加。

报告人：William G. Fahrenholtz(Curators' Professor of Ceramic Engineering）

Department of Materials Science and Engineering，

Missouri University of Science and Technology

报告题目：Design of ZrB₂ Based Ultra-High Temperature Ceramics for Improved Properties at Ultra-High Temperatures

报告地点：哈工大科学园C3栋特陶所4楼学术报告厅（417房间）

报告时间：2016年5月23日(周一）下午2：00

报告摘要:

This presentation will focus on the elevated temperature mechanical behavior of ZrB₂, ZrB₂-SiC, and ZrB₂-ZrC ceramics.  Ultra-high temperature ceramics (UHTCs) including ZrB₂ have been proposed for use in extreme environments associated with applications such as sharp leading edges of hypersonic flight vehicles, flow path components in scramjet propulsion, plasma-facing walls in nuclear fusion reactors, and ceramic inserts in lightweight armor systems.  These applications expose UHTCs to heat fluxes, temperatures, radiation levels, or strain rates that are beyond the capabilities of current structural materials.  However, previous studies of the elevated temperature mechanical properties of these materials have typically only reported data for one material, been limited to temperatures of ~1500°C, and have not provided insight into the mechanisms that limit strength at elevated temperatures.  In this presentation, the ultra-high temperature flexure strength, fracture toughness, and elastic modulus were measured from room temperature up to at least 2200°C with further analysis performed to identify strength-limiting flaws and failure mechanisms at elevated temperatures.  After analyzing the properties of the conventional ZrB₂ and ZrB₂-SiC ceramics, insights into the mechanical behavior at ultra-high temperatures were used to design ZrB₂-ZrC ceramics with improved strength at temperatures above 2000°C.  The desired attributes were determined to be high relative density, increased eutectic temperature compared to ZrB₂-SiC, and a final grain size of more than 5 µm.  The resulting ceramics had a room temperature strength of ~700 MPa, but retained strengths of nearly 300 MPa up to 2300°C.  Additional speculation will be provided about the characteristics desired for materials with the highest possible strength and fracture toughness at temperatures above 2000°C.

报告人简介

William G. (Bill) Fahrenholtz is a Curators' Professor of Ceramic Engineering in the Department of Materials Science and Engineering at the Missouri University of Science and Technology (formerly University of Missouri-Rolla).  He earned B.S. and M.S. degrees in Ceramic Engineering at the University of Illinois at Urbana-Champaign in 1987 and 1989, respectively.  He completed his Ph.D. in Chemical Engineering at the University of New Mexico (UNM) in 1992.  From 1993 to 1999, Bill was a research assistant professor in the department of Chemical and Nuclear Engineering at UNM.  Since starting at Missouri S&T in 1999, Bill has received several awards including seven campus-wide faculty excellence awards, two teaching awards, and a prestigious CAREER award from the National Science Foundation.  He was elected a Fellow of the American Ceramic Society in 2007.  Bill teaches undergraduate and graduate courses on thermodynamics.  His current research focuses on the processing, characterization, and mechanical testing of advanced structural ceramics for use in environments with extreme thermal loads, mechanical forces, and/or chemical reactivities.  He has published over 120 papers in peer-reviewed journals and given over 50 invited presentations on his research.  He has been Principal Investigator or Co-Principal Investigator on over 50 grants from sources including industry, the National Science Foundation, and the Air Force Office of Scientific Research.

个人主页http://mse.mst.edu/facultystaffandfacilities/fahrenholtz/

3777金沙娱场城

2016年5月22日