Chip-type Sensors for Die-casting Process Monitoring

The demand for light metals has been increasing in an effort to achieve a decarbonized society. Die casting is widely used for processing light metals; however, it has the problem of low yield. In this study, we propose a chip-type sensor that can be attached to a die to diagnose defective products during the die casting process. Unlike buffer-rod type sensors, the chip-type sensor can be mounted in a minimally invasive manner without couplant. In this experiment, a chip-type sensor attached to a temporary mold was heated to 400 °C, the highest temperature attainable on the mold surface, by die-casting a light metal, and then cooled to room temperature. The results showed that the chip-type sensor received larger reflected waves from the mold bottom at 400 °C and room temperature after cooling, and that the ultrasonic transmission increased at the interface with the mold. This study shows that the chip sensor is an innovative sensor with excellent high-temperature characteristics.