Homogeneous coprecipitation of precursor for preparation of yttrium aluminum garnet

Pure yttrium aluminium garnet powders were prepared by homogeneous coprecipitation of the precursor. Urea was added to an aeqeous solution of yttrium sulphate and aluminium sulphate. Heating between 80 - 100 °C leads to a precipitate, conststing of ultra fine microspheres . After washing, drying and heating yttrium aluminium garnet powder was obtained

Sol gel synthesis for preparation of yttrium aluminium garnet

Sol-gel—synthesis for preparation of pure yttrium aluminium garnet powder with small grain size is subject of this ongoing study. Starting materials were sulfates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3A1SO1Z) pH during hydrolysis as well as temperature during calcination and conversion into YAG must be carefully chosen. Presence of water has an adverse effect on the degree of agglomeration. To avoid this the influence of dispersion liquids was studied and this led to optimized conditions for precipitation. Sintering behaviour is discussed

Coprecipitation of yttrium and aluminium hydroxide for preparation of yttrium aluminium garnet

Coprecipitation of yttrium and aluminium hydroxide for the preparation of pure yttrium aluminium garnet (YAG) powder with small grain size is the subject of this study. Starting materials are sulphates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3Al5O12), the pH during flocculation of the precursor must be chosen carefully. The presence of water increases the degree of agglomeration. To minimize agglomeration, the influence of dispersion liquids has been studied, leading to optimized conditions for precipitation

Sol gel synthesis for preparation of yttrium aluminium garnet

Sol-gel—synthesis for preparation of pure yttrium aluminium garnet powder with small grain size is subject of this ongoing study. Starting materials were sulfates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3A1SO1Z) pH during hydrolysis as well as temperature during calcination and conversion into YAG must be carefully chosen. Presence of water has an adverse effect on the degree of agglomeration. To avoid this the influence of dispersion liquids was studied and this led to optimized conditions for precipitation. Sintering behaviour is discussed

A practical solution for the diffusion equations in binary and multicomponent systems with constant intrinsic diffusion coefficients

A practical solution for the diffusion equations in binary and ternary systems is presented which leads to a prediction of the concentration-penetration curves, diffusion paths, and the values for the intrinsic and interdiffusion fluxes. The model is very simple and gives insight into a variety of diffusion phenomena and zero-flux planes. The model has been applied to systems in which the intrinsic diffusion coefficients are constant and which, as far as ternary systems are concerned, are thermodynamically ideal. Although not mathematically exact, the results agree within the expected experimental accuracy with exact solutions presented in the literature. Even if the intrinsic diffusion coefficients are not constant, or if the ternary system is not thermodynamically ideal, the results agree semi-quantitatively with experimental results found in the literature. With some adaptations the agreement will be still better

Optimalisering van poeder compactie

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Optimalisering van poeder compactie

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