Abstract
A newly developed ultrasonic high temperature sensor and its application to an m-situ monitoring of a solid/liquid interface during unidirectional solidification of an aluminum alloy (Al-12.6%Si) are presented. The developed sensor mainly consists of a piezoelectric ultrasonic transducer (UT), a cooling system and a clad titanium (Ti) buffer rod. The longitudinal velocity monitoring during melting and solidifying processes of the Al alloy is successfully performed using the developed sensor. Then, attempts to monitor the solid/liquid interface of the alloy have been made at frequency of 2.25 MHz. A reflected echo from a stable solid/liquid interface has been clearly observed. Furthermore, The behavior of the echoes from the growing interface during unidirectional solidification process has been monitored. From the behavior of the echoes, the location and growth rate of the advancing interface can be determined.
