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The effect of nano-TiO2 addition on the properties of mullite-zirconia composites prepared by slip casting  [PDF]
Badiee S.H.,Otroj S.,Rahmani M.
Science of Sintering , 2012, DOI: 10.2298/sos1203341b
Abstract: The mullite-zirconia composites were prepared by reaction-sintering of alumina and zircon powder. Besides, the slip casting method was employed for fabrication of these composites. Then, the effect of nano-TiO2 addition on the properties of these composites was investigated and the results were compared with micro-sized TiO2. Hence, the physical properties, phase composition, flexural strength and microstructure of these composites after firing at 1600°C were studied. The results showed that the flexural strength of composite tends to increase with the addition of 0.5 wt.% nano-TiO2. It is attributed to the formation of larger size rod-like ZrO2 and enhanced ceramic bonding between them.
Tunable-slip boundaries for coarse-grained simulations of fluid flow  [PDF]
Jens Smiatek,Michael P. Allen,Friederike Schmid
Physics , 2007, DOI: 10.1140/epje/i2007-10311-4
Abstract: On the micro- and nanoscale, classical hydrodynamic boundary conditions such as the no-slip condition no longer apply. Instead, the flow profiles exhibit ``slip`` at the surface, which is characterized by a finite slip length (partial slip). We present a new, systematic way of implementing partial-slip boundary conditions with arbitrary slip length in coarse-grained computer simulations. The main idea is to represent the complex microscopic interface structure by a spatially varying effective viscous force. An analytical equation for the resulting slip length can be derived for planar and for curved surfaces. The comparison with computer simulations of a DPD (dissipative particle dynamics) fluid shows that this expression is valid from full-slip to no-slip.
Fabrication of YAG Transparent Ceramics using Slip Casting with Ethanol
ZHOUJun,, PAN Yu-Bai, LI Jiang, ZHANG Wen-Xin,,KOU Hua-Min, LIU Wen-Bin, GUO Jing-Kun
无机材料学报 , 2011, DOI: 10.3724/sp.j.1077.2011.00254
Abstract: High―quality YAG transparentceramics were fabricated by vacuum sintering technique using the slip casting with anhydrous ethanol as the dispersion medium. The in―line transmittances of the polished sample with the thickness of 3 mm are about 79% in the visible band and 80% in the infra―red band, respectively, which are close to the the oretical transmittance of 84%. The average grain size of the sample sintered at 1800 is about 30 &mgr;m. There are fewpores and no impurities or secondary phases at inner grains or grain boundaries.It can be expected that the anhydrous ethanol slip casting method is a very promising way for the transparent ceramic forming.
XIA Yuebo WANG Zhongguang State Key Laboratory for Fatigue and Failure of Materials,Institute of Metal Research,Academia Sinica,Shenyang,China
金属学报(英文版) , 1992,
Abstract: Comparing with ordinary ploycrystalline materials sized to μm grade,the slip morphology ofthe coarse grained polycrystalline pure Al is characterized by:(1)several slip domains occurin a grain,and in same domain,several slip systems operate at same time or one after anotherintensely,a beautiful and neat slip pattern is forming on the specimen surface;(2)for highΣ-value coincident and random grain boundaries,the grain boundary affecting zone(GBAZ),bout 50—120μm wide,is favourable site to form intergranular crack at early fa-tigue life easily,and migration or slide of the boundaries were often observed.While lowΣ-value near-coincident grain boundaries show a higher degree of slip continuity and straincompatibility than high Σ-value ones.Intergranular crack is not easily nucleated at lowΣ-value near-coincident boundaries;and(3)due to suppression of grain boundary slip attriple grain boundary node,the high Σ-value and random grain boundary among the threeboundaries of tricrystal crack easily during cyclic deformation.
Slip Casting and Pressureless Sintering of ZrB2-SiC Ceramics  [PDF]
WANG Xin-Gang,LIU Ji-Xuan,KAN Yan-Mei,ZHANG Guo-Jun,WANG Pei-Ling
无机材料学报 , 2009, DOI: 10.3724/sp.j.1077.2009.00831
Abstract: The dispersion of ZrB2 particles in water was investigated using polyethyleneimine (PEI) as a dispersant. Results showed that the ZrB2 slurry had a isoelectric point of pH=5.7. The application of PEI changed the isoelectric point of the ZrB2 slurry to pH=11.5. High solids loading (45vol%) ZrB2-20vol% SiC slurries were prepared at pH=8.0 by adding 1.0wt% PEI. The green body prepared by slip casting had a relative density of 53%. The effects of boron as a sintering aid on the pressureless sintering process of the ZrB2-20vol% SiC ceramics were investigated. Nearly fully dense ZrB2- SiC composites were obtained by sintering at 2100 or 3 h. The sintered ceramics demonstrated a Vickers hardness of (17.5 .5)GPa, a flexure strength of (406 1)MPa,and a fracture toughness of (4.6 .4)MPa ¤m1/2.
A Comparison of Fracture Resistance of Zirconia Copings Made with CAD/CAM Technology and Slip Casting Technique
Torabi K.,Ahangari AH.,Salehi S.,Motamedi M.
Journal of Dentistry , 2011,
Abstract: Statement of Problem: Zirconia has been introduced as an appropriate structure for fabricating metal free copings. A major advantage of such restorations is esthetic concerns; however, due to its high strength, zirconia can also be used in posterior areas. One of the recent methods of making these restorations is CAD/CAM machines.Purpose: This study aimed to evaluate the fracture resistance of zirconia copings fabricated by two methods, CAD/CAM and slip castingMaterials and Method: 32 brass dies were fabricated for this study and divided into two groups of 16 dies each. Zirconia copings were made by CAD/CAM machine for one group and by slip casting method for the other. The copings were cemented to dies by a resin-modified glass ionomer (GC plus). A hardened steel ball with a diameter of 5 mm was used to apply the load to the copings in the long axis of the dies at a crosshead speed of 0.5 mm/min. Then the amount of force needed to fracture each coping was recorded. Independent Sample T-test was used to compare the two groups. Results: The average of fracture resistance for the CAD/CAM group was 1411± 424 N and for the slip cast group it was 1542±412 N, having no significant difference ( p > 0.05).Conclusion: Zirconia copings made by CAD/CAM and slip casting methods have no significant difference in fracture resistance.
Effect of solid content variations on PZT slip for tape casting  [PDF]
Gang Jian,Qingxian Hu,Sheng Lu,Dongxiang Zhou
Processing and Application of Ceramics , 2012,
Abstract: Lead zirconate titanate (PZT) particles with pure tetragonal structure were synthesized by solid-state reaction method and used for preparation of slurries with different solid contents (34–80 wt.%). Then, PZT thick films were fabricated by the nonaqueous tape casting method. It was shown that the slurry prepared from ball-milled particles exhibited better rheology properties than slurry from particles which were not ball-milled. Measurement of sedimentation volumes and zeta potentials indicated particle aggregation, resulting in weak stability of the slurries with high solid contents. The microstructure, piezoelectric and ferroelectric properties of PZT sintered films were investigated in terms of solid contents. Ceramic films prepared from the slurry with solid contents of 73 wt.% had the optimal structure and properties. After poling at 200 °C with an applied field of 1.2 kV/cm, a d33 of 294 pC/N was achieved; typical ferroelectric properties were also observed with a Ps of 38 μC/cm2.
The Influence of Slip Characteristics and Casting Parameters on the Thickness of Thin Films Obtained by Tape Casting
Ivanchenko S.E.,Dulina I.O.,Nikulin A.G.,Kyrpal R.O.
Proceedings of the International Conference Nanomaterials : Applications and Properties , 2013,
Abstract: Tape casting slips with different composition have been prepared using BaTiO3 nanopowder with a particle size in range of 20-25 nm. Ethanol, low polar organic solvent and menton were used as the solvents. Polyvinylbutyral and Butvar were used as binders. Dibutyl phthalate and polyethylene gly-col where used as plasticizers. Rheological properties of BaTiO3 suspensions were carried out on a rotary rheometer. Casted tapes have been characterized by optical microscopy and optical profilome-try. Suspensions for tape casting characterized by pseudoplastic and pseudoplastic-dilatancy nature of the flow. The thickness of thin ceramic tapes depended on the height of doctor blade gap, the speed of the carrier and the viscosity of the suspension along with it’s rheological characteristics. Thickness of ceramic green tape in a greater extent determinated by the casting parameters, composition of the suspension and its viscosity. The average tape thickness was 2.5 μm for low viscosity slips and near 5 μm for high viscosity slips with same blade gap in 50 μm. Roughness of tape depended on type of used solvent and its polarity and varies between approximately 500 nm for low polar solvent up to 1 μm for polar one.
Electrical Porcelain Production From Selected Kaolin Deposit in South Western Nigeria Using Slip Casting
International Journal of Materials and Chemistry , 2012, DOI: 10.5923/j.ijmc.20120203.01
Abstract: The production of Electrical porcelain by slip casting using Ikere-Ekiti Kaolin and clay from South Western Nigeria was the focus of this work. Atomic Absorbtion Spectrometric(AAS) analyses of samples of Ikere-Ekiti Kaolin and clay, Ile-Ife clay and Iwo Kaolin was done. AAS analyses showed Iwo Kaolin and Ile-ife clay having low alumina and high impurity contents making them low refractory. Initial tests confirmed its low refractoriness as Iwo Kaolin could not withstand the bisque firing at 900℃ cracking extensively. Thus Ile-ife clay and Iwo Kaolin were disqualified as candidate materials for electrical porcelain production. Ikere-Ekiti kaolin and clay found to be high in alumina content and having low impurity contents were used in the experimental production. Results showed Ikere –Ekiti kaolin and clay suitable for porcelain production. Values of standard refractory tests fell within standard values for porcelain production.
Characterization of PVDF/HAP composites for medical applications
Braga, Francisco José Correa;Rogero, Sizue Ota;Couto, Ant?nio Augusto;Marques, Rodrigo Fernando Costa;Ribeiro, Alexandre Antunes;Campos, Jo?o Sinézio de Carvalho;
Materials Research , 2007, DOI: 10.1590/S1516-14392007000300005
Abstract: biomaterials (composites and blends) play a major role in the health of modern society. this paper reports on the preparation and characterization of polyvinylidene fluoride (pvdf) and hydroxyapatite (hap) composites, analyzing the incorporation of hap in pvdf and investigating their mechanical properties and cytotoxicity (biocompatibility) for use in bone restoration and filling. the material was prepared in film form by the casting method. pvdf pellets were dissolved in dimethylacetamide (dma), a hap/dma emulsion was prepared. the materials were mixed in proportions of 100/00, 90/10, 80/20, 70/30, 60/40, 50/50, 40/60, 30/70 in weight and left to dry in an oven, resulting in homogeneous, flexible films which were characterized by scanning electron microscopy (sem), energy dispersive spectroscopy (eds), x ray diffractometry (xrd), contact angle measurement, and by mechanical and cytotoxicity tests.
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