Phase formation processes in the zone of directional laser irradiation of compacted Al_2O_3- TiO_2- Y_2O_3 mixtures have been investigated. It has been established that phase formation was carried out within the framework of binary systems Al_2O_3- Y_2O_3 and Y_2O_3- TiO_2. The texture of the surface of tracks and the microstructure of the obtained crystalline body depend on the ratio of the phases formed during rapid cooling of the melt and temperature distribution of the material in longitudinal and transverse directions in heating.