Effect Of Filler Composition Research Articles

Heterogeneous material joining of sapphire and TC4 alloy with a functionally graded interface

AbstractThe natural high brittleness of sapphire leads to its poor machinability, which limits its application shape and size. The connection between sapphire and metal provides a new method to prepare large‐size sapphire components and complex structural parts. In this study, sapphire and TC4 alloy were joined by spark plasma sintering (SPS) diffusion technology with Al2O3‐Ti as interlayer fillers. The effects of filler composition, sintering temperature, microstructure, and phase distribution on the strength of the joint were explored. The results showed that sapphire and TC4 could be well connected by SPS with Al2O3‐Ti fillers. The microstructure of the joint showed no obvious defect or element enrichment. The optimized shear strength of sapphire/interlayer(Al2O3‐Ti)/TC4 joint reached 121 MPa, and the fracture path mode was sapphire‐interlayer‐TC4, indicating the strong bonding between the heterogeneous materials. The sapphire/interlayer(Al2O3‐Ti)/TC4 structure could relieve the residual stress caused by the difference in the thermal expansion coefficient in direct connection between sapphire and TC4.

Effects of filler composition, loading, and geometry on the dielectric loss, partial discharge, and dielectric strength of liquid metal polymer composites

With the goal of enabling the design of liquid metal polymer composites (LMPCs) with desired electrical and mechanical properties while preventing premature dielectric aging and failure, the dielectric breakdown characteristics of LMPCs containing galinstan (GaInSn), barium titanate (BTO), iron (Fe), and mixtures thereof are investigated. The dielectric properties including dielectric loss (tan δ), partial discharge inception electric field (PDIE), and breakdown electric field (Ebd) are investigated. According to the study, LMPCs with a higher overall filler concentration tend to show higher tan δ, lower PDIE, and lower Ebd. The study also demonstrates that these dielectric properties vary by the type of filler even with an equally maintained filler concentration. This is due to the distinct filler conductivity, permittivity, and geometry that cause differences in the electric field distribution within the composites. To provide further insights into the observed experimental results, finite element analysis (FEA) models were developed and analyzed.

Pressureless joining of SiC ceramics with magnesia‐alumina‐silica glass ceramics

AbstractLiquid phase sintered SiC ceramics were joined using magnesia‐alumina‐silica (MAS) glass‐ceramic fillers without applied pressure. Four different filler compositions with 9.3–25.2 wt.% MgO, 20.7–33.6 wt.% Al2O3, and 49.2–68.1 wt.% SiO2 were studied. The effects of filler composition and joining temperature (1450–1600°C) on the joint strength were investigated. All compositions exhibited an optimum joining temperature at which the maximum joint strength was obtained. A low joining temperature resulted in poor wetting of the SiC substrate due to the high viscosity of the filler. Whereas a high joining temperature caused dewetting and large unfilled sections in the interlayer due to the deleterious interfacial reactions. The joint strength was inversely proportional to the interlayer thickness, which was a function of filler composition and joining temperature. The SiC ceramic joined at 1525°C with MgO‐25 wt.% Al2O3‐60 wt.% SiO2 filler exhibited a four‐point bending strength of 286 ± 40 MPa.

The Effect of Filler Composition and Shape to Sound Capability Insulation and Modulus Elasticity Natural Fiber Galam Wood (Melaleuca Leucadendra) - Polyester

Making and testing for sound insulation materials from natural fiber composite (Galam wood fiber and polyester matrix) to analyze sound transmission loss and modulus of elasticity. Natural fiber that used is sawdust and wood chips and using polyester as matrix. Wood material chosen due to the availability of abundant so easily obtained and also a waste timber Galam is wasted in the process of building construction. Specimen made in disc shape with 10 cm of diameter and 1 cm thickness. Sound intensity measured in insulated room with sound level meter and speaker as sensor and source and run with variation in frequency of transmitted sound wave. With sound transmission loss theory, sound insulating capability could be analyzed. Measurement of modulus of elasticity is needed to determine deflection capability in loaded condition so it may be a consideration in their application. The result of this research is the best insulation properties is composite with 7% saw dust as filler on 800 Hz sound frequency and the highest value of Elasticity is composite material with 18% wood chip filler.

Dry fractionation of olive pomace for the development of food packaging biocomposites

Three lignocellulosic fractions with contrasted properties were produced by dry fractionation of olive pomace (OP): a stone-rich fraction (SF) rich in cellulose and having high polarity, a pulp-rich fraction (PF) richer in lignin and less polar, and a crude pomace fraction (CF) with intermediate properties. These fractions were used as fillers in two thermoplastic matrices, i.e. polyprolylene (PP) and polyhydroxybutyrate-co-valerate (PHBV). Tensile tests showed a decrease of both the stress and the elongation at break for all biocomposites, while the Young’s modulus was not significantly affected. At low filler contents, no effect of filler composition was observed whereas at high filler content (30 wt%), the decrease in the stress at break was less pronounced for PHBV-PF, with respective reduction values of 36%, 65% and up to 78% for PHBV-PF (30%), PHBV-CF (30%)and PHBV-SF (30%) composites, as compared to the neat PHBV. The elongation at break also greatly decreased according to the filler content. The highest reduction was recorded in the case of SF fillers, with a reduction of 74% for PHBV-SF composites. Mechanical properties were better preserved in the case of the PF filler due to better interfacial adhesion towards the matrices, as revealed by work of adhesion calculations, SEM observations and mechanical modelling. Water vapour permeability (WVP) of both matrices was increased in presence of both SF and CF fillers, while oxygen permeability was not significantly affected by the fillers. As an example, WVP increased from 0.9 ± 0.1 × 10−12 mol m−1 s−1 Pa−1 for the neat PHBV up to 15.1 ± 2.6 × 10−12 mol m−1 s−1 Pa−1 for PHBV-CF (30%). This supports a promising use of SF/CF fractions in sustainable biocomposites packaging for respiring food products, the PF-based formulations being more appropriate for non-respiring and water sensitive products. Our results demonstrated that the conditioning of lignocellulosic biomass by dry fractionation is important for the control of bio-based fillers properties and the resulting functionalities of biocomposites. Besides, the PP-based composites developed in this study allow reducing costs and dependence to fossil resources, while PHBV-based biocomposites also have the advantage of being fully bio-based and biodegradable.

Effect of Filler Composition and Post Weld Heat Treatment on Mechanical and Metallurgical Properties of GTA Welded AISI 409M Stainless Steel Joints

Effect of Filler Composition and Post Weld Heat Treatment on Mechanical and Metallurgical Properties of GTA Welded AISI 409M Stainless Steel Joints

Effect of Copper-based Fillers Composition On Spreading and Wetting Behaviour

Wetting and spreading of molten brazing filler material are important factors that influence the brazing ability of a joint to be brazed. Several investigations into the wetting ability of a brazing filler alloy and its spreading area in the molten state, in addition to effects of brazing temperature on the contact angle, have been carried out. Generally, the composition of copper-based filler and temperature affect spreading of molten brazing filler material during brazing. Wetting by and interfacial reactions of the molten brazing filler material with the metallic substrate, especially, affect strongly the spreading of the filler material. In this study, the effects of filler composition and brazing temperature on the spreading of molten brazing filler metallic alloys were investigated. MBF 2005 (Cu, 5.7wt.%Ni, 9.7wt.%Sn, 7.0wt.%P), MBF 2002 (Cu, 9.9wt.%Ni, 4.0wt.%Sn, 7.8wt.%P) and VZ 2250 (Cu, 7.0wt.%Ni, 9.3wt.%Sn, 6.3wt.%P) alloys were used as brazing filler materials. Pure copper block and a rectangular plate were employed as the base metal. Brazing filler material and metallic base plate were first washed with acetone. Brazing was performed at 750°C and 800°C under Ar gas for 30 minutes using an electrically heated furnace, after which, the original spreading area, defined as the sessile drop area, and the apparent spreading area were both evaluated. It was observed that the spreading area and wetting angle influenced by the composition of copper-based filler.

Reactive air brazing of YSZ-electrolyte and Al2O3-substrate for gas sensor sealing: Interfacial microstructure and mechanical properties

A YSZ/Al2O3 layered structure was successfully reactive air brazed using AgCuO fillers. The interaction mechanism between the filler and ceramics was systemically analyzed. The effects of filler composition on the interfacial microstructure and joint properties were investigated. AgCuO fillers possessed good wettability on the YSZ and Al2O3 ceramics. Ag had diffused into the ceramic substrates, but the width of the diffusion layer at the YSZ interface (∼10 nm) was narrower than that at the Al2O3 substrate (∼20 nm). Further HRTEM observations confirmed interatomic bonding between the CuO and the ceramics. The lattice mismatches at the Al2O3/CuO and YSZ/CuO interfaces were 0.98% and 2.97%, respectively. The filler alloy composition had a major influence on the microstructure and shear strength. The CuO phase preferentially precipitated at the Al2O3 interface. Consequently, the continuous CuO and CuAl2O4 layers gradually formed at the Al2O3 interface with increasing CuO content in the filler. The maximum shear strength (∼45 MPa) was obtained when the composition was Ag-8mol%CuO.

Hysteresis of the viscoelastic properties and the normal force in magnetically and mechanically soft magnetoactive elastomers: Effects of filler composition, strain amplitude and magnetic field

Hysteresis in dynamic modulus, loss factor and normal forces of magnetoactive elastomers (MAEs) comprising various proportions of small (3–5 μm) and large (50–60 μm) ferromagnetic particles are experimentally studied using dynamic torsion performed at a fixed oscillation frequency in varying DC magnetic fields. It is shown that hysteresis is a characteristic feature of MAEs observed both under increasing/decreasing magnetic field strength and increasing/decreasing strain amplitude. This hysteresis is attributed to the specific rearrangement of the magnetic filler network under simultaneously applied magnetic field and shear deformation. Rheological properties of the magnetic filler network formed in the magnetic field and, therefore, the rheological properties of MAEs depend strongly on the filler composition and the magnetic field magnitude. Larger magnetic particles and higher magnetic fields provide stronger magnetic networks. Both factors result in the extension of the linear viscoelastic regime to larger strain amplitudes and lead to higher values of shear storage and loss moduli. It is found that the hysteresis width maximises at an intermediate magnetic field where it is attributed to the balance between elastic and magnetic particle interactions. This is apparently where the most significant restructuring of the magnetic network occurs. The hysteresis width decreases with increasing fraction of large particles in the magnetic filler. The loss factor grows significantly when the magnetic network is physically broken by large strains γ > 1%. A huge (more than one order of magnitude) increase of normal force at maximum magnetic field strengths is observed. It is predicted that any physical quantity depending on the internal structuring of the magnetic filler should demonstrate hysteresis either with a changing magnetic field and constant deformation amplitude or under variable deformation in a constant magnetic field.

Translucence Study through New Experimental Hybrid Composites

Translucence parameters for 3 series of experimental hybrid composites were investigated using three-chromatic coordinates such as L* a* b* CHROMA technique using a type C illuminant geometry with the scope of 8o. The materials of each series contain in the same ratio different copolymers and a filler mixture (simple and mixed hydroxyapatite-ZrO2 or SiO2 powders and glass powders with barium oxide, respective strontium oxide, or quartz powder). The purpose was to determine the effect of filler composition of composites on translucence. The analysis shows that these materials have more or less translucence. CHROMA determinations indicate that for the composite that has as filler quartz microparticles anh hydroxyapatite nanoparticles, the translucence registered is higher. Results leading to the idea that chemical composition and the size of inorganic phase are important to obtain translucent composite materials that have very natural in appearance. Keywords: translucence, hybrid composites, CHROMA method.

Properties and osteoblast cytocompatibility of self-curing acrylic cements modified by glass fillers

Materials filled with a silicate glass (MSi) and a borate glass (MB) were developed and compared in terms of their in vitro behavior. The effect of filler composition and concentration (0, 30, 40 and 50 wt%) on the curing parameters, residual monomer, water uptake, weight loss, bioactivity, mechanical properties (bending and compression) and osteoblast cytocompatibility was evaluated. The addition of bioactive glass filler significantly improved the cements curing parameters and the mechanical properties. The most relevant results were obtained for the lower filler concentration (30 t%) a maximum flexural strength of 40.4 Pa for MB3 and a maximum compressive strength of 95.7 MPa for MSi3. In vitro bioactivity in acellular media was enhanced by the higher glass contents in the cements. Regarding the biological assessment, the incorporation of the silicate glass significantly improved osteoblast cytocompatibility, whereas the presence of the borate glass resulted in a poor cell response. Nevertheless it was shown that the surviving cells on the MB surface were in a more differentiated stage compared to those growing over non-filled poly(methyl methacrylate). Results suggest that the developed formulations offer a high range of properties that might be interesting for their use as self-curing cements.

Effect of filler composition and incorporation of additives on the mechanical properties of polypropylene composites with high loading lignocellulosic materials

The mechanical properties of wood polymer composites consisting of polypropylene and mixed sawdust of meranti shorea spp. dominant and rice husk filler have been studied. Three different filler loadings of 50, 60, and 70 wt% were used and the process of compounding and extrusion was carried out using a twin-screw extruder. Increase in flexural modulus and tensile modulus are observed while tensile strength, elongation at break, flexural strength, and Izod impact decrease with increasing filler loading. Poor interaction between wood filler and the plastics is believed to be the main reason for the decreasing trend. Maleic anhydride grafted polypropylene (MAPP) was used in the formulation to improve the interfacial adhesion between the two components. Addition of the MAPP shows some improvement, particularly at 1%, and further increment of the MAPP did not show any significant impact on the properties tested.

Effect of filler composition and crosslinker concentration on the tribological behavior of spent germ particle-based polymeric composites

Thermosetting composites have been prepared by the use of a biobased resin and spent germ filler, which is a byproduct from a wet ethanol production plant. Microscale tribological measurements were performed on samples with different concentrations of the filler as well as the crosslinker using a ball-on-flat reciprocating microtribometer. Microscale friction and wear behavior during dry sliding were evaluated using a spherical silicon nitride probe (radius 1.2mm) and a conical diamond (radius 100μm, cone angle 90°) probe to impose different contact conditions. Finally, a pin-on-disc tribometer was used to study the macroscale wear properties at high loads against an alumina pin. Scanning electron microscopy (SEM) images of wear tracks on the samples were obtained to elucidate deformation mechanisms. All samples showed evidence of abrasive wear in both micro- and macro-scales. It was found that an increase in the concentration of the filler resulted in higher friction coefficients against Si3N4, while an increase in the concentration of the crosslinker lowered the abrasive wear depth. These results provide some insight into the effectiveness of using biobased spent germ–tung oil polymer composites as potential tribomaterials.

Stearate intercalated layered double hydroxides: effect on the physical properties of dextrin-alginate films

Glycerol-plasticized dextrin-alginate films were prepared by solution casting. They contained a fixed amount (16.6% mass/dry film mass) of functional filler based on the reaction products of the LDH, Mg4Al2(OH)12CO3·3H2O, and stearic acid (SA). The films were characterized using infrared (IR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effect of filler composition on water vapour permeability and film stiffness was determined. The ratio of stearic acid (SA) to the LDH (Mg4Al2(OH)12CO3·3H2O) was varied over the full composition range. Infrared spectroscopy and X-ray diffraction studies confirmed that the SA intercalated into the LDH. The Young’s modulus of films attained a maximum value (more than double the value for the neat film) at a filler composition of 60% SA. The water vapour permeability showed a broad minimum at filler compositions of 50–80% SA. Scanning electron microscopy revealed that in this composition range the filler assumes a high-aspect-ratio platelet morphology. This contrasts with the sand rose morphology of the LDH starting material and the globular dispersion of 100% SA in the film.

Effects of filler composition on flexibility of microfilled resin composite

The effects of the filler composition on physical and mechanical properties of microfilled composites was investigated by measuring water absorption, solubility, compressive, flexural, and impact strength. A series of experimental composites, consisting of UDMA/TEGDMA comonomer matrix and prepolymerized fillers, was fabricated. The prepolymerized fillers were composed of hydrophobic colloidal silica and two monomers in varying ratios, trimethylolpropanetrimethacrylate (TMPT), and polyesterdiacrylate (PEDA). TMPT/PEDA ratios were 100:0, 64:36, 46:54, 18:82, and 0:100%. There were no significant differences in water sorption and solubility, regardless of the amount of PEDA monomer. Young's modulus and modulus of resilience increased with decreasing PEDA ratio. Fracture energy exhibited drastic changes (30.1 x 10(-5) J to 93.4 x 10(-5) J). The highest value of flexural strength (96.0 +/- 3.5 MPa) was obtained when the TMPT-PEDA filler was 46:54. The impact strengths of composites fabricated with TMPT-PEDA filler of 46:54 (11.2 +/- 1.4 kJ/m(2)), 18:82 (10.6 +/- 3.2 kJ/m(2)), and 0:100 (13.1 +/- 3.8 kJ/m(2)) were significantly higher than those with 100:0 (6.0 +/- 1.8 kJ/m(2)) or 64:36 (7.1 +/- 2.4 kJ/m(2)). Based upon the results, it was concluded that the mechanical properties of microfilled composites were improved by the modification of prepolymerized filler composition.

Tuning of final performances of unsaturated polyester composites with inorganic microsphere/platelet hybrid reinforcers

Physical properties of fly ash/mica hybrid reinforced unsaturated polyester composites in both uncured and cured state have been studied with special reference to the effect of loading composition, nature of filler surfaces and surface treatment of fillers. Besides, effect of filler surfaces on curing characteristics of composites were all examined. In uncured state, viscosity measurement for composites was carried out. Tensile properties for cured fly ash/mica hybrid reinforced composites were found to increase with addition of mica in total filler. Effects of filler composition and silanization on loss factor ( tan δ ) were all discussed.

Effects of filler composition and surface treatment on the characteristics of opaque resin composites

The effects of filler composition and surface treatment of titanium dioxide (TiO2) on the shear bond strength to noble metal and mechanical properties of opaque dental resin composites were assessed. A series of fillers for resin composites were prepared with untreated TiO2 or treated silica/alumina-coated TiO2 with silane coupling agent; these fillers were replaced with silanized SiO2 in increasing amounts. Each of various powder compositions were mixed with the liquid and applied to the surface of a silver-palladium-copper-gold (Ag-Pd-Cu-Au) alloy and light cured. A light-activated resin-veneering composite material was placed on top with the use of a brass ring mold and light cured. Specimens were stored at 37 °C in water for a period of 24 h. Additionally some specimens were thermocycled at 4 °C and 60 °C in water baths for 1 min each for 5000 cycles before shear mode testing was performed. Light-activated opaque resin composites containing filler with specific filler compositions of 50 wt% of untreated TiO2—50 wt% of silanized SiO2 (untreated TiO250) and 40 wt% of untreated TiO2—60 wt% of silanized SiO2 (untreated TiO240) showed higher shear bond strengths to the Ag-Pd-Cu-Au alloy than any other specific compositions when no thermocycling was involved. Surface treatment of TiO2 filler and TiO250- and TiO240-opaque resin composites prepared thereof showed significantly higher shear bond strengths than untreated TiO250- and TiO240-opaque resin composites when subjected to thermocycling. Surface-treated opaque resin composite had significantly higher compressive and flexural strength than untreated opaque resin composite after immersion in water for 1 month. Scanning electron microscopy of the fractured opaque resin composite surface showed an interface failure between TiO2 and the matrix resin for untreated composite, and cohesive failure within the resin for surface-treated composite. Surface-treated TiO250 and TiO240 may be clinically useful as the filler for light-activated opaque dental resin composites. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 525–530, 2001

Effects of filler composition and surface treatment on the characteristics of opaque resin composites.

The effects of filler composition and surface treatment of titanium dioxide (TiO2) on the shear bond strength to noble metal and mechanical properties of opaque dental resin composites were assessed. A series of fillers for resin composites were prepared with untreated TiO2 or treated silica/alumina-coated TiO2 with silane coupling agent; these fillers were replaced with silanized SiO2 in increasing amounts. Each of various powder compositions were mixed with the liquid and applied to the surface of a silver-palladium-copper-gold (Ag-Pd-Cu-Au) alloy and light cured. A light-activated resin-veneering composite material was placed on top with the use of a brass ring mold and light cured. Specimens were stored at 37 degrees C in water for a period of 24 h. Additionally some specimens were thermocycled at 4 degrees C and 60 degrees C in water baths for 1 min each for 5000 cycles before shear mode testing was performed. Light-activated opaque resin composites containing filler with specific filler compositions of 50 wt% of untreated TiO2-50 wt% of silanized SiO2 (untreated TiO2(50)) and 40 wt% of untreated TiO2-60 wt% of silanized SiO2 (untreated TiO2(40)) showed higher shear bond strengths to the Ag-Pd-Cu-Au alloy than any other specific compositions when no thermocycling was involved. Surface treatment of TiO2 filler and TiO2(50)- and TiO2(40)-opaque resin composites prepared thereof showed significantly higher shear bond strengths than untreated TiO2(50)- and TiO2(40)-opaque resin composites when subjected to thermocycling. Surface-treated opaque resin composite had significantly higher compressive and flexural strength than untreated opaque resin composite after immersion in water for 1 month. Scanning electron microscopy of the fractured opaque resin composite surface showed an interface failure between TiO2 and the matrix resin for untreated composite, and cohesive failure within the resin for surface-treated composite. Surface-treated TiO2(50) and TiO2(40) may be clinically useful as the filler for light-activated opaque dental resin composites.

The effect of comonomer composition, silane heating, and filler type on aqueous TEGDMA leachability in model resin composites.

Experimental composites using either bisGMA/TEGDMA or UEDMA/ TEGDMA matrices, quartz or barium glass fillers, and 2 different filler silanization methods were evaluated regarding monomer leachability in distilled water. The leached amount was detected and quantified using gas chromatography. The results showed that twice as much TEGDMA is leached from a bisGMA/TEGDMA based composite than from an UEDMA/ TEGDMA based composite, when both contain 50 wt% TEGDMA. The hypothesis suggested that the higher degree of cure of UEDMA/TEGDMA based composites would be reflected in a lower monomer leaching value, and this hypothesis was supported by the findings. Whether such a correlation exists within groups of UEDMA/TEGDMA based matrices having different degrees of cure was not determined and needs to be investigated in future studies. Variables such as filler composition and silane treatment did not affect the leaching values of TEGDMA in water. That finding suggests that future studies should target differences in matrices, and that the need for considering effects of filler composition and silane treatment methods should not receive the same priority.

Physical characteristics of baked carbons employing binary filler compositions

A study of the characteristics of baked carbons employing different binary fillers constituted from a coarse and a fine sieve fraction of calcined petroleum coke taken in different relative proportions, has been carried out to determine the most suitable filler composition. The effect of filler composition on the properties of resulting carbons is discussed and an attempt is made to correlate the different characteristics.