Modelling microstructural evolution of porous polycrystalline materials and a numerical study of anisotropic sintering

Ch'ng, H. N.; Pan, Jia-Yu

doi:10.1016/j.jcp.2004.10.015

Cited by 36 publications

(27 citation statements)

References 45 publications

(66 reference statements)

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“…These models clearly show that oriented elongated pores lead to anisotropic shrinkage. In Ch'ng and Pan 73 model calculations for Al 2 O 3 showed that an elongated pore shrinks faster in width than in length direction which coincides with our experimental findings of larger shrinkage in ZD direction compared with in‐plane shrinkage. The numerical results also show that the shrinkage anisotropy rate is controlled by kinetic factors like surface diffusion, grain‐boundary diffusion, and grain‐boundary migration in addition to pore shape and orientation.…”

Section: Ceramic Formationsupporting

confidence: 87%

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Preceramic Paper‐Derived Ceramics

Travitzky

Windsheimer

Fey

et al. 2008

Journal of the American Ceramic Society

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A novel class of preceramic paper may serve as a preform to manufacture lightweight as well as multilayer ceramic products. In this article, we discuss the formation, microstructure, and properties of preceramic papers and their conversion into ceramic materials. Oxide as well nonoxide ceramics were processed into single‐sheet, corrugated structures, and multilayer ceramics. A high filler loading and uniform distribution of ceramic fillers involves control of colloidal surface interaction including electrostatic, electrosteric, and mechanical retention. Sintering of an oxide‐loaded preceramic paper in air results in highly porous products, with the porosity shape and distribution templated by the pulp fiber used in papermaking. In the case of carbide‐loaded paper, dense composite materials are obtained by reactive infiltration processing. Anisotropic properties of machine‐fabricated preceramic paper and bonding interfaces in multilayer stacks give rise to anisotropic mechanical properties of the resulting ceramic composites. Noncatastrophic failure was observed when tensile loading stress was applied parallel to the interfaces (in‐plane loading). Applying well‐established paper processing technologies, including laminated object manufacturing, ceramic structures of complex shape and size can easily be processed, offering a high potential for economical manufacturing.

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Section: Ceramic Formationsupporting

confidence: 87%

“…The primary cause of anisotropic shrinkage in these systems is the preferential orientation of anisotropic pores. The sintering shrinkage of a compact with elliptical pores has been modeled 65,72,73 . These models clearly show that oriented elongated pores lead to anisotropic shrinkage.…”

Section: Ceramic Formationmentioning

confidence: 99%

Preceramic Paper‐Derived Ceramics

Travitzky

Windsheimer

Fey

et al. 2008

Journal of the American Ceramic Society

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“…Substitution of pulp fibers by rigid ZrO 2 -fibers caused a reduced in-plane-shrinkage of 19% while out-of-plane shrinkage perpendicular to the paper plane increased slightly to 34% (D). Micromechanical model calculations [24] for Al 2 O 3 showed that an elongated pore shrinks faster in width than in length direction which coincides with our experimental findings of larger shrinkage in ZD direction compared to in-plane shrinkage. The numerical results also show that the shrinkage anisotropy can be controlled by manipulating the ratios between the kinetic mobilities of surface diffusion, grain-boundary diffusion, and grain-boundary migration.…”

Section: B Gutbrod Et Al/preceramic Paper Derived Alumina/zirconia supporting

confidence: 90%

Preceramic Paper Derived Alumina/Zirconia Ceramics

et al. 2011

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Preceramic paper offers a novel approach for manufacturing of lightweight ceramic structures applying versatile paper shaping technologies. Substitution of bioorganic pulp fibers in alumina loaded preceramic paper by inorganic short zirconia fibers was investigated. A retention of more than 90 wt% was achieved by a combination of cationic and anionic retention aids. Powder packing density in the paper sheet decreased with increasing amount of non‐deformable zirconia fibers used to substitute highly deformable pulp fibers. Applying post‐pressing, however, resulted in a pronounced improvement of packing density while retaining excellent flexibility and strength of the preceramic paper preform. Thus, preceramic paper containing a zirconia fiber volume fraction of 19% sintered at 1 600 °C attained a rupture strength measured by ball‐on‐three‐balls loading of 120 ± 17 MPa (porosity 44%) which after pressure consolidation of the paper increased to 180 ± 49 MPa (porosity 28%).

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“…18,19 In all these cases a higher shrinkage in the z-direction was observed; the primary cause of anisotropic shrinkage in these systems is attributed to the orientation of anisotropic particles. 11,16,[19][20][21][22][23][24][25] Wakai et al simulated the shrinkage behavior of spherical particles, which are not oriented but which also exhibit anisotropic shrinkage behavior caused by particle rearrangement during sintering due to an inhomogeneous distribution of contact points. 26 http://dx.doi.org/10.1016/j.jeurceramsoc.2015.01.032 0955-2219/© 2015 Elsevier Ltd. All rights reserved.…”

Section: Introductionmentioning

confidence: 99%