METHOD OF PRODUCING TRANSPARENT HIGH-ALLOY ER:YAG-CERAMICS

摘要

FIELD: manufacturing technology.;SUBSTANCE: invention relates to production of transparent ceramic material with yttrium-aluminum garnet (Er:YAG) structure high-alloyed with erbium ions for use as a laser material in medicine and optical communication. Method involves grinding of ceramic powder obtained by reverse heterophase co-precipitation together with sintering additive, followed by drying, granulation, molding, vacuum sintering, annealing, grinding and polishing, wherein initial components used are powders of oxides of given composition Er_nY_(3-n)Al₅O₁₂, where n is amount of dopant ion and n=0.3–1.8, obtained by reverse heterophase coprecipitation through sputtering; sintering additive tetraethylorthosilicate (TEOS) in amount of 0.8 wt% is added to the initial ceramic powder of amount of ceramic powder and ground in a planetary-type mill at rate of 100–300 rpm in drums of high-purity zirconium dioxide or in teflon drums with balls from high-purity zirconium dioxide for 20–60 minutes in a medium of deionised water at a ratio of: ceramic powder and TEOS to total amount of grinding bodies and deionised water equal to 1:6.5; deionised water is removed by drying the suspension to obtain a powder granule on a spray dryer at temperature of 100–120 °C; after granulation powders are molded by uniaxial semi-dry pressing at pressure of 50–100 MPa, with exposure for 0–5 minutes with subsequent cold isostatic pre-pressing at pressure of 150–300 MPa and holding time of 1–10 minutes; after isostatic pressing vacuum sintering is carried out at 1750-1,800 °C, holding time is 5–30 hours, degree of vacuum 10^-4–10^-6 Pa, or prior to vacuum sintering step, pressed samples are heat treated at temperature of 600–800 °C, holding time 4–8 hours; samples Er:YAG-ceramics after vacuum sintering are annealed at temperature of 1,300-1,500 °C, holding time 5 hours. Invention uses simple technology which is practically feasible not only for Er³⁺ ions, but also for activation by different rare-earth ions – Yb³⁺, But³⁺, Dy³⁺, Eu³⁺, Tm³⁺.;EFFECT: obtained ceramic material Er:YAG has high light transmittance of more than 86 %, high thermomechanical properties and strong intensity of the fluorescence band at 1½ mcm.;4 cl, 3 dwg, 4 ex