Ceramic Filler Material Research Articles

Fabrication of a reverse-engineered custom scan body as a digital solution for recording implant position: A dental technique

A technique for the reverse engineering of the implant-abutment connection to fabricate a custom scan body is described. The implant-abutment connection was designed using the exocad software program, the scan body with screw channel was designed with the Blender software program, and the file was either 3-dimensionally printed in definitive tooth-colored resin with ceramic filler material or milled in polyetheretherketone (PEEK). This technique offers an accurate, cost-effective digital solution for implant optical scanning that can replace prefabricated scan bodies that may not be available for all implants. (J Prosthet Dent xxxx;xxx:xxx-xxx).

Thermal conductive thin, flexible composite sheet of boron nitride aggregates and alumina for enhanced through plane conductivity

In electronics sector, the trend of miniaturization will undoubtedly continue to drive forward with several technological advancements, however, there are some crucial issues especially in the thermal management of electronic devices that limits to what is pragmatically and economically feasible. For ensuring efficient thermal dissipation and preventing temperature overloads at local sites, in this work, an advanced thermal filler material (BN aggregate) synthesized via a cost effective and scalable route from h-BN (Hexagonal Boron Nitride) is proposed. To assess the suitability of the BN aggregate as a conventional ceramic filler material and its effectiveness for thermal management, a thermally conductive thin composite sheet is (200 μm) fabricated with the synthesized BN aggregates and spherical Al2O3. The thermal sheet made out of an optimized ratio between the Al2O3 and BN aggregate delivers an excellent through-plane (k⊥) and in-plane (k∥) thermal conductivity of 8.142 W/m.K and 5.601 W/m.K respectively. Even at higher filler concentration, this thin sheet which mimics a papery film, practically endured no deterioration in the mechanical integrity. This thermal sheet given its reasonable thermal and mechanical properties can be employed in electrical devices that demands high power cycles. With wearable technology gaining greater attention in the recent days, the proposed filler system when dispersed in polyethylene fibers, may find potential applications in thermoelectric devices, smart textiles, wearable displays and health monitoring systems.

Scratch characteristics of particle and fiber reinforced polymer composite

Abstract Composite Materials are known for their tailor-made properties. The metal or/and ceramic filler material improves the mechanical properties of E-glass fiber (E) reinforced polymer base composite. In the present work, hybrid composite laminates are made with two different stacking sequences of filler materials, such as Al and SiC in woven E-glass reinforced epoxy composite by hand lay method. The stacking sequences of the laminates are E/Al/E/SiC/E/Al/E (Al rich composite) and E/SiC/E/Al/E/SiC/E (SiC rich composite). The Al and SiC part icle sizes and phases are identified using SEM and XRD, respectively. To maintain orthotropic properties, Eglass woven is used in the present work. The mechanical properties of Al rich and SiC rich composites are compared with the help of tensile test, flexural test, hardness test, impact test and micro scratch test. The impact on particle size and distribution of subsurface filler material on scratch resistance is studied with three different constant loads such as 50, 75 and 100 N. The scratch geometry of Al and Si rich composite studied using white light interferometer and SEM image which indicates interfacial strength and the mechanism involved in failure of the material. In addition, water absorption rate and swelling of Al rich and SiC rich composites are also studied.

Effect of hexagonal boron nitride on the coefficient of frictions of organic-inorganic hybrid polymer thin films for metal surface coatings

Organic-inorganic hybrid coatings were developed via a sol-gel method using hexagonal boron nitride (h-BN) as a ceramic filler material incorporated into a polymeric matrix. To investigate the effects of h-BN on the properties of polymer-based coatings, parameters such as hardness, coefficient of friction, and hydrophobicity were investigated. Colloidal silica (CS), methyltrimethoxysilane (MTMS), water, and acid catalyst containing coatings were prepared by varying the content of h-BN from 10% to 25%. All the coatings were prepared with the same experimental procedure and coated on 1050 aluminum alloy plates. The compensating contents of MTMS and colloidal silica with a fixed molar ratio of MTMS and CS were set to be 1:1.2, and a specific amount of the catalyst was utilized. Coatings were examined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDS). The most promising physical properties were determined to be the pencil hardness of 8B, adhesion strength of 5B, coefficient of friction of 0.332 N, and water contact angle of 114.75°. Therefore, it can be concluded that the h-BN improves the physical properties of polymeric coatings. In addition, this study demonstrates the effect of h-BN on the adherence of polymer matrix-based hybrid coatings.

Manufacture of a ceramic paper for art applications

Ceramic paper products are mostly used as high temperature ceramic insulation products. They offer an effective solution for most demanding heat management and insulation applications. The objective for this research project was to create a ceramic paper like product that combines the advantages of paper fibers, ceramic filler, and a clay product into one product, which can be produced on a continuous base with a paper machine. The produced ceramic paper product had a ceramic filler level between 59.68% and 78.8% with a basis weight between 322.9 g/m² and 693.7 g/m², and a final moisture content of 58.6% to 44.7% respectively. The wooden fiber served as a support medium for the ceramic filler material during production on the paper machine and during the conversion process into art pieces. During firing in a kiln, the fiber material combusted and the ceramic filler material mixture acts as common pottery clay, holding the desired shape of the art pieces produced.

Ba(Zn<SUB align="right">1/3Ta<SUB align="right">2/3)O<SUB align="right">3 filled PTFE composites for microwave substrate applications

Ba(Zn1/3Ta2/3)O3 (BZT) ceramic filler material is prepared through solid state ceramic route. The phase purity and crystal structure of BZT filler have been studied using powder X-ray diffraction technique. Different weight percentage of BZT filler has been incorporated in the PTFE matrix through sigma mixing (SM), extrusion (E), calendering (C) followed by hot pressing (H) (SMECH) process. Distribution of the ceramic particulates in the PTFE matrix was analysed by scanning electron microscopy. The effect of BZT ceramic filler content on the microwave dielectric properties of the PTFE composites was studied in the microwave frequency region using X-band waveguide cavity perturbation technique. Moisture absorption characteristics of the composite samples are studied as per IPC-TM 650 2.6.2.1 method.

Characterization and improvement of LTCC composite materials for application at elevated temperatures

Glass–ceramic composites combine the material properties of its ceramic filler material and the ability of densification via glass assisted sintering. Especially for LTCC materials, were densification has to be achieved at temperatures below 900 °C to enable the usage of metals of improved conductivity in conducting pastes, this densification mechanism in combination with crystallization of the glassy matrix is used successfully. However, the glass’ softening point also limits the use of LTCCs at elevated temperatures, since their mechanical stability is dependent on the remaining glass composition's transition range and its crystallization products. Because LTCC multilayers gain increasing interest in manufacturing sensor devices, a better understanding of their mechanical and electrical behavior in the elevated temperature regime is needed to broaden their field of applications. Therefore, five commercially available LTCC materials were investigated in regard to their temperature dependence of mechanical and electrical properties. Based on the understanding gained from these results, a novel LTCC will be presented and its properties will be discussed.

Aqueous Tape Casting Route for Microwave Substrates

Driven by the continuing trend towards increasing circuit density, very thin films of highly filled fluoropolymeric matrix composite substrates with uniform microstructure have become highly sought after. Aqueous tape casting is an ideal process for making such uniformly filled composite layers with high filler loading yet with minimum anisotropy. Colloidal suspension of fluoropolymer in water was taken as the source of polymer. Separately, a highly stable ceramic suspension in aqueous medium was prepared, matching the pH, dispersant and zeta potential with that of the fluoropolymer. After thorough mixing, other additives are added to form tape casting slurry. Tapes thus formed were characterized by TG/DTA to find out the process window. Tapes were stacked, binder burnt and thermolaminated to form substrates. XRF analysis of samples at different locations confirms the uniform distribution of ceramic filler material. Density, dielectric constant and loss factors were found to be closer to the theoretical values.

Structure modification of 0–3 piezoelectric ceramic/polymer composites through dielectrophoresis

Anisotropic material properties can be induced in ceramic/polymer composites by applying an alternating electric field of moderate strength during processing. Under suitable conditions, particles of a ceramic filler material that are randomly dispersed in a liquid polymer or pre-polymer can be polarized and they then exhibit a collective response to localized gradients in the electric field. Typically, the particles experience a mutually attractive force which causes them to form ‘pearl-chains’ or columnar structures spanning the gap between electrodes. If the fluid is solidified, for example by curing the polymer resin, then the newly formed structures can be fixed in place to produce a composite with directional electrical and mechanical properties. Direct visual observations were made for low volume fraction dispersions of pure lead titanate in an epoxy pre-polymer under the influence of an electric field. The observed interaction was correlated with low-field dielectric measurements and existing theory to identify optimum assembly conditions. The dielectric properties of the fluid are predominant and the formation of chain-like structures is found to be both field strength and field frequency dependent. The dielectric permittivities of a range of structurally modified composites were measured and compared with existing theoretical models of di-phasic materials.

A Low CTE Intermetallic Bipolar Plate

A low CTE bipolar plate is fabricated from a NiAl intermetallic and a ceramic filler material. By using inert, ceramic filler materials the intermetallic reaction of the NiAl system is controlled resulting in netshape formed plates with CTE comparable to the electrolyte and electrode ceramic layers. In addition, the combustion synthesis reaction moderated by the ceramic filler material creates significant porosity in the NiAl microstructure yielding a highly thermal shock resistant substrate material for the subsequent plasma deposited electrode and electrolyte layers. This paper outlines the powder metallurgy process parameters necessary to form these low CTE intermetallic plates.

Modeling of composite growth in the directed aluminum melt nitridation process

An attempt was made for the first time to model the pressureless infiltration of a porous preform, from first principles, as flow through a porous medium. To this end, a transient, two-dimensional, laminar flow model in a cylindrical polar coordinate system has been developed to predict the flow phenomena in the molten alloy-porous ceramic filler material system. Two different modeling approaches were considered for the porous preform, and their relative accuracy/adequacy was assessed for predicting the infiltration rate (i.e., composite growth). The sensitivity of model predictions to various assumptions and numerical approximations, such as the initial preform wetting height, gridsize distributions, and time-step size, were tested computationally. For a first approximation, a structure-sensitive parameter (β) on the order of 10−4 m, which is the same as that reported in the literature, gave reasonably accurate results. A hypothetical computation which assumed no nitride formation provided an activation energy value of 18 kJ/mol for a surface tension-driven infiltration process. In addition to these, the influence of process parameters such as particle size and operating temperature on the predicted results was investigated numerically and was shown to compare well with experimentally obtained data.

Gas-phase Selective Area Laser Deposition (SALD) joining of SiC

The laser-driven, gas-phase based SFF technique for joining together ceramic components with ceramic filler material, known as Selective Area Laser Deposition (SALD) Joining, was utilized in fabricating joined silicon carbide structures. Specifically, silicon carbide tubes were `welded' together by depositing silicon carbide from a gas phase reaction. A single laser beam deposition setup and a dual laser beam design were investigated. A gas environment of tetramethylsilane and hydrogen served as the deposition precursors. The quality of the joints were examined by bend tests and hermeticity measurements. In addition, the composition and morphology of the silicon carbide deposit was studied and is discussed here.