Transparent ceramics of LiAl5O8 prepared by spark plasma sintering

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F23%3A43926780" target="_blank" >RIV/60461373:22310/23:43926780 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Transparent ceramics of LiAl5O8 prepared by spark plasma sintering

Popis výsledku v původním jazyce

Transparent ceramics are a relatively new material form that serves as an alternative to the traditionally encountered glasses, polymers or highly transparent single crystals. They have found application in a variety of optical and electro-optical devices such as solid state lasers and scintillators, but also in some non-optical applications, e.g. armours. The fabrication of transparent ceramics usually involves a combination of chemical and physical processes, which are used to prepare a ceramic powder and compact the powder into a dense ceramic body. However, the optical properties of finished polycrystalline ceramics are closely related to their microstructure and to the presence of defects in it. Residual pores (located within grains or at grain boundaries), impurities or the actual grain boundaries (especially for optically anisotropic materials) are sources of light scattering, which deteriorates the optical properties of transparent ceramics. Therefore, transparent ceramics are commonly prepared from materials with an optically isotropic cubic structure using high purity powders, which leave porosity as the most significant factor for transparency.In this work, the preparation of LiAl5O8 transparent ceramics is presented using spark plasma sintering (SPS). Powder precursors were prepared using two methods, namely sol-gel method and solid state reaction. Before sintering, the powders were heat treated at 1200 °C and their phase composition was verified by XRD to be pure cubic α-phase of LiAl5O8. The powders were compacted into dense ceramic bodies by SPS using a two-step sintering program. The sintered bodies were further processed by grinding and polishing to achieve a mirror finish and a thickness of approximately 1 mm. Based on the investigation of transmittance in the UV-vis and NIR-MIR spectral regions, transparent ceramics with superior transparency were obtained from powders prepared by solid state reaction and the optimal sintering temperature is 1400 °C.

Název v anglickém jazyce

Transparent ceramics of LiAl5O8 prepared by spark plasma sintering

Popis výsledku anglicky

Transparent ceramics are a relatively new material form that serves as an alternative to the traditionally encountered glasses, polymers or highly transparent single crystals. They have found application in a variety of optical and electro-optical devices such as solid state lasers and scintillators, but also in some non-optical applications, e.g. armours. The fabrication of transparent ceramics usually involves a combination of chemical and physical processes, which are used to prepare a ceramic powder and compact the powder into a dense ceramic body. However, the optical properties of finished polycrystalline ceramics are closely related to their microstructure and to the presence of defects in it. Residual pores (located within grains or at grain boundaries), impurities or the actual grain boundaries (especially for optically anisotropic materials) are sources of light scattering, which deteriorates the optical properties of transparent ceramics. Therefore, transparent ceramics are commonly prepared from materials with an optically isotropic cubic structure using high purity powders, which leave porosity as the most significant factor for transparency.In this work, the preparation of LiAl5O8 transparent ceramics is presented using spark plasma sintering (SPS). Powder precursors were prepared using two methods, namely sol-gel method and solid state reaction. Before sintering, the powders were heat treated at 1200 °C and their phase composition was verified by XRD to be pure cubic α-phase of LiAl5O8. The powders were compacted into dense ceramic bodies by SPS using a two-step sintering program. The sintered bodies were further processed by grinding and polishing to achieve a mirror finish and a thickness of approximately 1 mm. Based on the investigation of transmittance in the UV-vis and NIR-MIR spectral regions, transparent ceramics with superior transparency were obtained from powders prepared by solid state reaction and the optimal sintering temperature is 1400 °C.

Druh

O - Ostatní výsledky

CEP obor

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OECD FORD obor

20504 - Ceramics

Projekt

<a href="/cs/project/VI20192022152" target="_blank" >VI20192022152: Vývoj nových materiálů pro detekci a účinné varování před ionizujícím zářením</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů