A novel method for solidification rate measurement of weld pool surface

A novel method for calculating the solidification rate of laser spot weld pool surface is presented. The surface temperature of weld pool during solidification process is measured by a point infrared sensor. Based on the difference in emissivity of the solid-liquid surface, the output data of infrared sensor, which can accurately reveal the liquid-solid transformation, is demonstrated. Therefore the solidification rate at different locations of the molten pool surface is obtained. Experiment result shows that the solidification rate is related to the weld geometry.