Krell, A.A.KrellSeidel, J.J.Seidel2022-03-092022-03-091994https://publica.fraunhofer.de/handle/publica/322604Technological principles are discussed to develop pressureless sintered, single and polyphase non- nanocrystalline microstructures of isometric grain shape on the basis of Al2O3 with a strength of about 700 MPa avoiding dissipation mechanisms like transformation-, microcrack- or whisker-toughening and grain bridging. Two essentials are (i) the use of technologies which produce sintered parts with small flaw sizes and - to minimize subcritical crack growth - (ii) extremely perfect grain boundary structures.deFestigkeitFormgebungstechnologiefracture toughnessgrain boundarygrain sizeKorngrenzenbruchzähigkeitKorngrenzenstrukturKorngrößemicrostructurepowder processingsintered aluminaSinterkorundstrengthsubcritical crack growthsubkritisches Rißwachstumsubmicron microstructureSubmikrometer-Gefüge666620conference paper