Local damage of HT-materials by laser irradiation in the SEM

By using a pulsed Nd:YAG laser the high temperature materials zirconium oxide, fine grain graphite and silicon nitride were rapidly irradiated (heating thermal shock) and their damage behavior was investigated. The laser beam parameters at sample surface were detected by a laser beam analyzing system and correlated with the local damage mechanisms of the materials as erosion, crack formation and solid-solid phase transformation. For the investigations image analysis, localized x-ray analysis, and the ion beam slope cutting technique were applied. The temperature field in the material was simulated by using temperature dependent material parameters for different laser beam parameters. The results illustrate both the strong influence of the temporal and spatial laser energy profile and the materials properties to the material damage.