VERFAHREN ZUM HERSTELLEN EINES VOLUMENBESTAENDIGEN PLASMA-SPRITZAUFTRAGS AUF ZIRKONBASIS

摘要

Spraying of zircon with a plasma flame contg. H+ and OH- ions from a water-stabilised burner results in the formation of a deposit consisting of a mixt. of tetragonal ZrO2 and glassy SiO2. Thus, the transition from the monoclinic ZrO2 to tetragonal ZrO2 occurring on heating (at 1050-1250 degrees C) with a 3% longitudinal shrinkage, and the reverse change on cooling (at 950-750 degrees C) is eliminated (it resulted in cracking of the deposit after a no. of thermal cycles). This method can be used for the formation of protective coatings or refractory articles such as crucibles (by plasma-spray deposition in a mould).