Monitoring of melting and solid state phase transformation induced by pulsed laser action on pure zirconium

Real time temperature monitoring is carried out by high speed high spatial resolution pyrometers. The obtained thermocycles are compared with a 2D transient heat transfer model, which permits calculation of the evolution (depth, volume, shape, etc.) of the molten pool as well as the solid state (β→α) phase transformation induced by the pulsed laser action. As a result, the correlation between surface temperature dynamics measured by pyrometer and parameters of phase transformations are studied. A phenomenological relation between molten pool evolution (obtained by simulation) and duration of solidification (measured by pyrometer) is presented for different values of the density energy flux.