Observe the temperature curve for solidification from high-speed video image

High-speed camera (HSC) is an advanced technology, which can be applied to observe the solid–liquid interface directly during solidification. It has never been reported that the temperature evolutions of solidification that was monitored by using cameras and their images. In this study, a new application of HSC technology was developed for the temperature evolution investigation. With this technology, the effects of the measured position, the thermocouple size and thermocouple sensitivity (delay) can be demonstrated in temperature measurement. It is important that the higher accuracy of temperature profiles can be obtained by the HSC technology. This method can be expected to analyze the temperature profiles of small melt-pool and subsequent rapid solidification process in additive manufacturing. In the end, we discussed the relationship of the recalescence rate and the solidification interface.