Novel Piezoelectric Ultrasonic Transducer for Die-Casting Process

In recent years, die casting of light metals such as magnesium and aluminum is required to realize a carbon-free society. However, there are yield rate issues due to defective products. In this study, we propose a chip-type sensor for monitoring during die casting and for detecting defective products. This chip-type sensor has a Bi<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf>Ti<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</inf>/TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>+SrCO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> sol-gel composite material attached to the top of the chip, which can operate for long periods at 500°C. The sensor was installed in a test mold, and the ultrasonic reflected wave was observed at 400°C, the maximum temperature of the surface of the die-casting mold for light metals. The transmittance of the interface between the chip and the mold increased as the temperature rose, and the transmittance remained high at room temperature after 400°C. From this, it was found that the chip-type sensor was suitable for use at high temperatures.