title: A model of blind zone for in situ monitoring the solid/liquid interface using ultrasonic wave.
abstract: To in situ monitor a solid/liquid interface to control metal qualities, the paper analysis blind models of the ultrasonic propagation in the solidifying molten metal with a solid/liquid interface in the Bridgman type furnace, and a mathematical calculation model of blind zone with different source locations and surface concavities is built. The study points out that the blind zone I is caused by ray bending in the interface edge, and the blind zone II is caused by totally reflection which is related with initial ray angle, critical refraction angle of solid/liquid media. A serial of simulation experiments are operated on the base of the model, and numerical computation results coincide with model calculated results very well. Therefore, receiver should locate beyond these blind zones in the right boundary to obtain time of flight data which is used to reconstruct the solid/liquid interface.
authors.affiliation: Department of Metallurgical Engineering, Chongqing University, Chongqing 400044, China.
authors.forename: Song
authors.initials: S
authors.lastname: Peng
authors.affiliation: College of Automation, Chongqing University, Chongqing 400044, China. Electronic address: yangqi@cqu.edu.cn.
authors.forename: Qi
authors.initials: Q
authors.lastname: Ouyang
authors.affiliation: Department of Metallurgical Engineering, Chongqing University, Chongqing 400044, China.
authors.forename: Z Z
authors.initials: ZZ
authors.lastname: Zhu
authors.affiliation: College of Computer Science and Engineering, Chongqing University of Technology, Chongqing 400050, China.
authors.forename: X L
authors.initials: XL
authors.lastname: Zhang
keywords: Blind zone; In situ monitor; Solid/liquid interface; Ultrasonic propagation