收藏本站  |  English  |  上海硅酸盐所  |  中国科学院  
首 页
 
当前位置:首页 >  学术交流
Laser-Induced Pressure-Wave and BarocAloric effect During flash diffusivity measurements
发布时间:2017-10-31 点击浏览:

SEMINAR

The State Key Lab of

High Performance Ceramics and Superfine Microstructure

Shanghai Institute of Ceramics, Chinese Academy of Sciences

中 国 科 学 院 上 海 硅 酸 盐 研 究 所 高 性 能 陶 瓷和 超 微 结 构 国 家 重 点 实 验 室

 

Laser-Induced Pressure-Wave and BarocAloric effect During flash diffusivity measurements


Hsin Wang

Oak Ridge National Laboratory, Oak Ridge, TN USA

 

时间:2017113日(星期五)10:00

地点:嘉定园区F51)会议室

 

欢迎广大科研人员和研究生参与讨论!

联系人:史迅2803

 

报告摘要:

Laser-induced pressure-wave and barocaloric effect was captured by an infrared detector during thermal diffusivity measurements. Very fast (< 1 millisecond) and negative transients during laser flash measurements were captured by the infrared detector on thin, high thermal conductivity samples. Standard thermal diffusivity analysis only focuses on the longer time scale thermal transient measured from the back-surface due to heat conduction. Previously, these negative transients or spikes were filtered out and ignored as noise or anomaly from the instrument. This study confirmed that the initial negative signal was indeed a temperature drop induced by the laser pulse. The laser pulse induced instantaneous volume expansion, and the associated cooling in the specimen can be explained by the barocaloric effect. The initial cooling (< 100 microsecond) is also known as thermoelastic effect in which a negative temperature change is generated when the material is elastically deformed by volume expansion. A subsequent temperature oscillation in the sample was observed and only lasted about one millisecond. The pressure-wave induced thermal signal was systematically studied and analyzed. The underlying physics of photon-mechanical-thermal energy conversions and the potential of using this signal to study barocaloric effects in solids are discussed.

报告人简介:

Dr. Hsin Wang is a distinguished R&D staff member from the Materials Science and Technology Division at ORNL. He received his bachelor’s degree in solid state physics from Tsinghua University in 1989, MS and Ph.D. in ceramic science from New York State College of Ceramics at Alfred University. He has been working at ORNL since 1995 focusing on transport properties measurements, energy conversion materials including thermoelectrics and thermal management and safety of Li-ion batteries.

 

 
 
【打印本页】【关闭本页】
版权所有 © 高性能陶瓷和超微结构国家重点实验室
地址:上海市长宁区定西路1295号 邮政编码:200050