Patent · US Active

Transparent alumina-based plate and method of making thereof

US12076886B2 · kind B2 · utility

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1References
7Claims
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Key dates

Filing dateDec 15, 2020
Grant dateSep 3, 2024
Priority date
Expiry dateDec 6, 2042

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC04B2235/787
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

The present disclosure provides a transparent alumina-based plate, and a hot-pressing method to make the transparent alumina-based plate from platelet alumina. Alumina powder with a platelet morphology was hot-pressed to transparency with pre-load pressures of about 0-8 MPa, maximum temperatures of about 1750-1825° C., maximum pressures of about 2.5-80 MPa, and isothermal hold times of 1-7 hours. A novel alumina-based plate has been prepared, wherein the plate has a thickness of 2-5 mm, an in-line transmission of at least 60-75% for a light with a wavelength range of 645-2500 nm, an in-line transmission variance of <15% over the wavelength range of 645-2500 nm, and a relative density of 99.00-99.95%.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.