% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @ARTICLE{Schlup:887815, author = {Schlup, Andrew P. and Costakis, William J. and Rheinheimer, Wolfgang and Trice, Rodney W. and Youngblood, Jeffrey P.}, title = {{H}ot‐pressing platelet alumina to transparency}, journal = {Journal of the American Ceramic Society}, volume = {103}, number = {4}, issn = {1551-2916}, address = {Westerville, Ohio}, publisher = {Soc.}, reportid = {FZJ-2020-04441}, pages = {2587 - 2601}, year = {2020}, abstract = {Alumina powder with a platelet morphology was hot‐pressed to transparency with preload pressures of 0‐8 MPa, maximum temperatures of 1750‐1825°C, maximum pressures of 2.5‐80 MPa, and isothermal hold times of 1‐7 hours. Optical transmission (in‐line and total), as well as optical losses (backward/forward scattering and absorption), of the hot‐pressed samples were measured and related to the microstructure. Higher hot‐pressing temperatures increase the in‐line transmission. A gray discoloration of the samples (indicative of high absorption) was minimized by heat treating the powder in air prior to hot pressing and reducing the preload pressure. Maximum pressures above/below 10 MPa increased porosity, which decreased in‐line transmission and increased backward/forward scattering. Lower densities at higher pressures are attributed to a pore‐swelling phenomenon. Increasing isothermal hold time decreased porosity, which increased in‐line transmission and reduced backward/forward scattering. Best optical properties with an in‐line transmission of $65.3\%$ at 645 nm (0.8 mm thick) were achieved by hot‐pressing heat‐treated platelet alumina powder with a preload pressure of 0 MPa, maximum temperature of 1800°C, maximum pressure of 10 MPa, and an isothermal hold time of 7 hours. This high in‐line transmission, despite its large grain size (65 µm), is attributed to crystallographic orientation of the platelets during hot pressing.}, cin = {IEK-1}, ddc = {660}, cid = {I:(DE-Juel1)IEK-1-20101013}, pnm = {899 - ohne Topic (POF3-899)}, pid = {G:(DE-HGF)POF3-899}, typ = {PUB:(DE-HGF)16}, UT = {WOS:000503637600001}, doi = {10.1111/jace.16932}, url = {https://juser.fz-juelich.de/record/887815}, }