Journal ArticleDOI
Grain Size Dependence of Hardness in Dense Submicrometer Alumina
Andreas Krell,Paul Blank +1 more
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TLDR
In this article, pressureless sintered alumina compacts with a submicrometer microstructure exhibit a hardness that approaches or even exceeds the level of advanced hot-pressed composites of Al{sub 2 O{sub 3} + 35 vol% TiC, whereas the strength of both ceramics is approximately the same.Abstract:
Pressureless sintered alumina compacts with a submicrometer microstructure exhibit a hardness that approaches or even exceeds the level of advanced hot-pressed composites of Al{sub 2}O{sub 3} + 35 vol% TiC, whereas the strength of both ceramics is approximately the same. The combination of reduced dislocation mobility (due to the small grain size), high density, and density homogeneity are the prerequisites for the surprisingly high hardness. Quasi-conventional powder processing is used to produce these outstanding alumina bodies.read more
Citations
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Effect of magnesia on zinc oxide stabilized nano alumina ceramic powder in sintering process and its impact on mechanical properties
T. Alam,K.H.A. Al Mahmud,M.F. Hasan,S.A. Shahir,Haji Hassan Masjuki,M.A. Kalam,Ahamad Imran,H.M. Mobarak +7 more
TL;DR: In this article, the properties of Al 2 O 3 powder were studied through incorporation of MgO Nano powder along with ZnO nano powder and followed by sintering at various temperatures.
Journal ArticleDOI
Preparation of dense nanostructured titania ceramic using two step sintering
TL;DR: In this article, a two-step sintering method was used to suppress grain growth in nanostructured TiO2 ceramics with a grain size of 110 nm and relative density of 97%.
Journal ArticleDOI
Effect of sintering conditions on optical and mechanical properties of MgAl2O4/Al2O3 laminated transparent composite fabricated by spark-plasma-sintering (SPS) processing
TL;DR: In this article , a one-step sparkplasma sintering (SPS) method was used to realize a high hardness in transparent MgAl2O4/Al 2O3 laminated composite.
Journal ArticleDOI
Mechanical properties of submicronic and nanometric boron carbides obtained by Spark Plasma Sintering: Influence of B/C ratio and oxygen content
TL;DR: In this paper, the effect of grain size on mechanical properties of sintered monoliths was investigated at the grain and macroscopic scales, and it was shown that nanostructured material exhibits finer grains than the sub-micronic material.
Journal ArticleDOI
The effects of MgO, ZrO2 and TiO2 as additives on microstructure and mechanical properties of Al2O3-Fap composite
TL;DR: In this paper, the effects of MgO, ZrO 2 and TiO 2 as additives during the densification of the Al 2 O 3 -26.5% Fap composites were investigated and the authors found that titania doping achieved 94% of the theoretical density and provided composites with a mechanical strength, a hardness and Young's modulus of 74 MPa, 684 Hv and 215 GPa, respectively.
References
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Journal ArticleDOI
Fracture Toughness Determinations by Indentation
Anthony G. Evans,E. A. Charles +1 more
Journal ArticleDOI
Plastic Deformation of Aluminum Oxide by Indentation and Abrasion
TL;DR: In this paper, transmission electron microscopy was used to show that high densities of dislocations are produced within the near surface regions by mechanical polishing with a fine diamond compound (0.25 μm).
Journal ArticleDOI
Solute induced hardening near grain boundaries in zone refined metals
TL;DR: In this article, a solute-clustering model is proposed for grain boundary quench-hardening based on preferential solutevacancy interactions and non-ideal thermodynamic behavior of the binary system.
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Synthesis, sintering, microstructure, and mechanical properties of ceramics made by exothermic reactions
TL;DR: Al2O3-TiC, Al2O 3-HfB2 powders were synthesized by the aluminothermic reduction of oxides in the presence of carbon or boron, and reacted powders are milled to reduce the size of agglomerates and subsequently densified without applied pressure to near theoretical density.