레이저 유도초음파(LBU)를 이용한 고온에서 물성측정에 관한 연구

A Study on the Material Properties in High Temperature by Using Laser Based Ultrasonic

In this research, using laser-guided ultrasonic inspection system to measure the properties at high temperatures was on purpose. One of propose laser-based ultrasonic technology is a non-contacted, remote measurements. It is possible to measure an ultrasound at high temperatures using laser-based ultrasonic because the benefits of laser-based ultrasonic was a remote and non-contact measurement, but convention methods was not possible at high-temperatures. For the detection of ultrasound at high temperatures were a variety of researches in progress. This study is divided into two parts. First, according to the direction of the progress of the ultrasound, properties at normal temperature were detected. Depending on the progress of the ultrasound direction, the velocity of ultrasound was measured and compared respectively. Secondly, the specimen into the high temperature-electric furnace, changes in temperature, and the measurement of the ultrasound signal. Temperature of the furnace was changed 0 ℃ to 1000℃. In conclusion, depending on the temperature rise has reduced the speed of ultrasound. And Young s modulus was also reduced. However, the Poisson s ratio was increased. In particular, the velocity of ultrasound and Young s modulus is the increasing decline in the near a 400℃. Through this research in high-temperature laser-based ultrasonic to prove that the ultrasound was ideal for transmitting and receiving. Additional research is needed to overcome the environmental restrictions.