Commercial Filler Research Articles

Effect of Relative Humidity on the Mechanical Properties of Micro and Nanocomposites of Polyvinyl Alcohol

The effect of relative humidity on the mechanical properties of poly(vinyl alcohol) (PVOH) micro and nanocomposites was evaluated. Two different commercial fillers (microcellulose and bentonite) were used as reinforcement. PVOH and PVOH composite films were prepared by casting technique. The incorporation of microcellulose increased the content of water absorption and the modulus, especially for the higher contents of filler. The effect of reinforcement on the mechanical properties was more pronounced at higher relative humidity. On the other hand, the incorporation of nanofiller produced a decrease in water absorption probably due to the decrease of mean free path of water molecules. The modulus of the nanocomposites improved from the matrix, but the mechanical properties are deteriorated by effect of the humidity.

Microstructure and hardness change in high temperature service depending on Mo content in 2.25Cr-1Mo steel weld metals

The microstructural characteristics and properties of 2.25Cr-1Mo weld metal were investigated at high temperatures by modifying the Mo content of commercial filler wires using the flux cored arc welding (FCAW) process. The microstructure of the as-welded specimens was composed of fine bainite and acicular ferrite, and the hardness and strength increased with increasing Mo content. Each weld metal was heat-treated at 400 °C, 500 °C, 600 °C and 700 °C for 24 h. The microstructure exhibited a tempered bainite structure after the heat treatment at 400 °C and 500 °C, whereas the bainite was slightly coarsened at 600 °C. Bulky ferrite with carbides that had transformed from the bainite dissolution was observed at 700 °C, and the hardness significantly decreased.

Weld Metal Grain Refinement of Aluminium Alloy 5083 through Controlled Additions of Ti and B

Abstract The refinement of the weld metal grain structure may lead to a significant change in its mechanical properties and in the weldability of the base metal. One possibility to achieve weld metal grain refinement is the inoculation of the weld pool. In this study, it is shown how additions of titanium and boron influence the weld metal grain structure of GTA welds of the aluminium alloy 5083 (Al Mg4.5Mn0.7). For this purpose, inserts consisting of base metal and additions of the master alloy Al Ti5B1 have been cast, deposited in the base metal and fused in a GTA welding process. The increase of the Ti and B content led to a significant decrease of the weld metal mean grain size and to a change in grain shape. The results provide a basis for a more precise definition of the chemical composition of commercial filler wires and rods for aluminium arc welding.

Development of filler wires for welding of reduced activation ferritic martenstic steel for India's test blanket module of ITER

Indigenous development of reduced activation ferritic martensitic steel (RAFMS) has become mandatory to India to participate in the International Thermo-nuclear Experimental Reactor (ITER) programme. Optimisation of RAFMS is in an advanced stage for the fabrication of test blanket module (TBM) components. Simultaneously, development of RAFMS filler wires has been undertaken since there is no commercial filler wires are available for fabrication of components using RAFMS. Purpose of this study is to develop filler wires that can be directly used for both tungsten inert gas welding (TIG) and narrow gap tungsten inert gas welding (NG-TIG), which reduces the deposited weld metal volume and heat affected zone (HAZ) width. Further, the filler wires would also be used for hybrid laser welding for thick section joints. In view of meeting all the requirements, a detailed specification was prepared for the development of filler wires for welding of RAFM steel. Meanwhile, autogenous welding trials have been carried out on 2.5 mm thick plates of the RAFM steel using TIG process at various heat inputs with a preheat temperature of 250 °C followed by various post weld heat treatments (PWHT). The microstructure of the weld metal in most of the cases showed the presence of some delta-ferrite. Filler wires as per specifications have also been developed with minor variations on the chemistry against the specified values. Welding parameters and PWHT parameters were optimised to qualify the filler wires without the presence of delta-ferrite in the weld metal and optimised mechanical properties. Results showed that the weld metals are free from delta ferrite. Tensile properties both at ambient and at 500 °C are well above the specified values and much higher than the base metal values. Ductile Brittle Transition Temperature (DBTT) has been evaluated as −81 °C based on 68 J criteria. The present study highlights the basis and methodology adopted for the specification of filler wires and its development followed by the optimisation of welding procedures and PWHT adopted on the Indian made RAFM steel to be used for the TBM components of ITER.

Filler selection for weldments in type 316L stainless steel, for hot organic acid service

The weld metal corrodes much faster than the parent metal if type 316L steel welded with a matching filler is exposed to hot organic acids. Nine commercial filler metals were evaluated by preparing welded coupons and exposing them to different plant environments (with different organic acid mixtures and temperatures) for several months. The filler metals were chosen to yield different solidification modes, and to vary chromium, molybdenum and nickel contents. Only filler metals that are much more highly alloyed than the parent metal gave lower corrosion rates than the parent metal. Partitioning during and after solidification, and the average alloy content, both affect weld bead corrosion.

Study and Selection of the Most Appropriate Filler Materials for an Al/Cu Brazing Joint in Cooling Circuits

Five dissimilar commercial filler alloys with four fluxes were used in the aluminum to copper diffusion brazing process. The filler metal alloys composition comprised AlSi12, ZnAl 96/04, ZnAl 98/02, AlSi12 + ZnAl 98/02, and AlSi12 + ZnAl 85/15 alloys. The use of these filler alloys on the assembly of piping for cooling circuits has been analyzed. Brazing aluminum to copper is difficult, principally due to the substantial differences between their thermal properties and the generation of intermetallic compounds in the joint, especially when certain mechanical strength of the joint is needed. Pipes of Al 1350 and Sf-Cu R220 were brazed using five brazing alloys, and the section of the joint was analyzed after polishing and etching. Microhardness tests were also carried out. Furthermore, the microstructure and phase constitution for the copper to aluminum brazing were exhaustively studied by means of metallography, electron probe microanalyzer (EPMA), and X-ray diffraction (XRD). The experiment results obtained indicated that the ZnAl 96/04 filler alloy represents the optimum solution due to the low microhardness, homogeneous microstructure and lack of defects (pores and cracks) shown.

Optimal Weld Parameters, Weld Microstructure, Mechanical Properties, and Hydrogen Absorption: An Effective Analysis

Weld bead-in-grooves were deposited on low alloy, high strength steel plates (ASTM A 517 Grade “F”) with a commercial flux-cored filler wire, Auto-MIG 420, at different welding conditions. Microstructure and mechanical properties of welds were characterized by means of optical microscopy, SEM, TEM, EPMA, microhardness measurements, tensile tests, and Charpy impact tests. Hydrogen content of weld metals in as-weld condition and after exposing in simulated service condition was measured by LECO Gas Analyzer. Microstructure of weld metals consisted primarily of lath martensite with small amount of M-A constituents (Martensite-Austenite alternating layers). For some particular welding conditions, such as higher heat input and lower preheat temperatures etc., acicular ferrite is observed with lath martensite. Welds consisting of acicular ferrite in the microstructure showed improved mechanical properties as well as lower hydrogen absorption. The study provides guidelines for selecting proper welding conditions, which results in lower propensity to absorb hydrogen during service, as well as better mechanical properties. Necessity of post-weld heat treatment processes, which is mainly performed to achieve toughness, may be reduced; consequently saving cost and time of the welding process.

Application of lime kiln dust as a filler in the natural rubber industry

AbstractLime kiln dust (LKD) obtained from kraft chemical recovery systems by conversion of calcium carbonate (CaCO3) back into calcium oxide (CaO) for reuse in the causticizing process, is mainly composed of CaCO3. A two‐stage conventional mixing procedure was used to incorporate LKD into natural rubber (NR). For comparison purposes, four commercial fillers, stearic acid coated CaCO3, ground CaCO3, silica, and carbon black, were also used. The effect of these fillers on the curing characteristics and mechanical properties of NR materials at various loadings ranging from 0 to 60 phr were studied. The results indicate that the use of LKD filler resulted in a lower Mooney viscosity and shorter curing time in the NR materials. The incorporation of LKD into NR improved the Young's modulus and hardness but decreased the tensile strength and tear strength. However, LKD was better in processability than the commercial fillers. Scanning electron micrographs revealed that the morphology of the rubbers filled with reinforcing fillers, such as silica and carbon black, was finer and more homogeneous compared to the those of the rubbers filled with LKD and commercial CaCO3. The dispersion of LKD and commercial CaCO3 fillers in the rubber matrix was discontinuous, which in turn, generated a weak structure compared with the reinforcing fillers. According to these observations, LKD could be used as a cheaper filler for NR materials where improved mechanical properties are not critical. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Chemically modified sugarcane bagasse as an improving agent for the properties of styrene–butadiene rubber

AbstractThe agrowaste of sugarcane bagasse was used as a filler to improve the properties of rubber. Sugarcane bagasse waste was ground and sieved to a particle size less than 75 nm and then purified and chemically modified by an acetylation method and stearic acid adsorption. The modified bagasse was incorporated into styrene–butadiene rubber formulations with different concentrations (20, 30, 50, and 70 phr) in comparison with carbon black and hisil, commercial fillers used in industry. The physicomechanical properties of the rubber vulcanizates were determined before and after thermal aging at 90°C. The retained values of the tensile strength, elongation at break, and equilibrium swelling increased as the concentration of the modified bagasse increased in styrene–butadiene rubber vulcanizates until 50 phr; after this concentration, the retained values of each property decreased. Rubber vulcanizates containing modified bagasse with a concentration of 50 phr may be better for retained values of the physicomechanical properties and equilibrium swelling in comparison with those containing carbon black, hisil, and untreated bagasse. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Utilization of limestone dust waste as filler in natural rubber

The possibility of using limestone dust waste (LDW) as a filler in natural rubber (NR) was investigated. First, the basic properties of LDW were characterized; LDW was then incorporated into NR and the compound properties were determined. Comparison of the reinforcing effect of LDW and other commercial fillers such as light-precipitated calcium carbonate (PCC) and nanoprecipitated calcium carbonate (NPCC) was made. The results revealed that even though the addition of LDW has little effect on compound processability, it has a negative effect on most mechanical properties, e.g., tensile strength, tear strength, and abrasion resistance, of the vulcanizate. Among the three fillers, the degree of reinforcement could be placed in the following order: NPCC > PCC > LDW. Due to their relatively low specific surface area and thus low reinforcement ability, both LDW and PCC can be grouped as nonreinforcing fillers, whereas NPCC, the specific surface area of which is relatively high, could be grouped as a semi-reinforcing filler for rubber.

Comparative Physical Properties of Hyaluronic Acid Dermal Fillers

Hyaluronic acid (HA) fillers are becoming the material of choice for use in cosmetic soft tissue and dermal correction. HA fillers appear to be similar, but their physical characteristics can be quite different. These differences have the potential to affect the ability of the physician to provide the patient with a natural and enduring result. The objective of this article is to discuss the key physical properties and methods used in characterizing dermal fillers. These methods were then used to analyze several well-known commercially available fillers. Analytical methods were employed to generate data on the properties of various fillers. The measured physical properties were concentration, gel-to-fluid ratio, HA gel concentration, degree of HA modification, percentage of cross-linking, swelling, modulus, and particle size. The results demonstrated that commercial fillers exhibit a wide variety of properties. Combining the objective factors that influence filler performance with clinical experience will provide the patient with the optimal product for achieving the best cosmetic result. A careful review of these gel characteristics is essential in determining filler selection, performance, and patient expectations.

Metallic Hollow Sphere Structures Manufacturing Process

AbstractThis paper focuses on manufacturing process of regular Metallic Hollow Sphere Structures (MHSS) through brazing technique. As a large stress level is generally confined into the necks formed by brazed spheres, the influence of the filler material on mechanical behavior of cellular metal has been studied. The microstructures of joints resulting from nickel hollow spheres brazing with different commercial fillers “MBF 30” and “MBF 1006” were compared by Scanning Electron Microscopy (SEM) and microhardness testing. These studies revealed a wide boron diffusion into nickel shells through grain boundaries for “MBF 30” brazing, with the formation of borides in a fine brittle eutectic structure. Conversely it was observed that the eutectic structure concentrates at the necks for “MBF 1006” and can be completely eliminated by diffusion-brazing, despite of the shells thinness. The uniaxial compressive tests of HSP specimens have shown two different strain mechanisms depending on brazing process.

Brazing Process to Repair Wide Gap Cracks of Inconel 738 Superalloy Components

ABSTRACTBrazing process is a cost effective technique to repair wide gap cracks in turbine components made from difficult to weld nickel base superalloys. In this process boron and silicon are used as melting point depressants, however, form hard and brittle intermetallic compounds with nickel (eutectic phases) which are detrimental to the mechanical properties of brazed joints. In this paper the effect of brazing parameters such as temperature and time on final microstructure of brazed joint of nickel base superalloy Inconel 738 using a commercial filler metal alloy (Ni-11Cr-3.5Si-2.25B-3.5Fe) was investigated. The microstructure of the joint layer was characterized by optical and scanning electron microscopy; chemical composition was carried out by energy dispersive X-ray spectrometry (EDS) microanalysis and microhardness testing. The results showed that the formation of eutectic microconstituents, within the joint regions, was significantly influenced by the brazing parameters and gap size, also that formation of eutectic constituents decreased by allowing a sufficient amount of time for a complete isothermal solidification to take place at the brazing temperature.

High Water Barrier Nanobiocomposites of Methyl Cellulose and Chitosan for Film and Coating Applications

Polysaccharides and protein biopolymers are of increasing interest for their use as sustainable film and coating materials. However, their main drawback in these applications is their inherent high water permeability and low water resistance at high relative humidity conditions. In this study, two specifically designed commercial fillers of different nature and aspect ratios were successfully incorporated into two polysaccharides: methyl cellulose and chitosan. The morphology study indicated that a good dispersion with intercalation of the fillers was observed in both matrices. The water barrier properties of the nanobiocomposites were found to be enhanced to a significant extent, particularly for the higher aspect ratio filler, as compared to the pure matrix materials, while the biodegradability of the composite materials was maintained.

The Effect of Partial Replacement of Paper Sludge by Commercial Fillers on Natural Rubber Composites

The effects of partial or complete replacement of two commercial fillers, carbon black (CB) and silica on cure characteristics, tensile properties, fatigue life, morphological properties, and rubber—filler interaction of paper sludge (PS) filled natural rubber composites were elucidated. Compounding was carried out on a two-roll mill with total filler loading of 30 phr. Results indicate that maximum torque, tensile strength, elongation at break, tensile modulus, and fatigue life increased the cure time while the scorch time decrease with increasing carbon black loading ratio of PS/CB filled natural rubber composites. On the other hand, increased loading of silica in PS/silica weight ratio resulted in an increment in cure time, scorch time, maximum torque, elongation at break, and fatigue life but not significantly altering tensile strength and tensile modulus of the natural rubber composites. In addition, PS/silica filled natural rubber composites exhibit lower maximum torque, tensile properties, and fatigue life compared to the PS/CB filled natural rubber composites. Rubber—filler interaction and SEM micrograph studies proved that the higher interaction between carbon black and natural rubber occurred in PS/CB filled natural rubber composites rather than PS/silica filled natural rubber composites.

Effects of base and filler chemistry and weld techniques on equiaxed zone formation in Al–Zn–Mg alloy welds

Equiaxed zone (EQZ) formation in Al–Zn–Mg alloy welds as affected by base metal, filler metal chemistry and weld techniques is studied. Filler metal chemistry and welding techniques have great influence on the formation of EQZ microstructure as base metal composition has. In an effort to characterise the equiaxed grain zone formation in Al–Zn–Mg alloy welds two commercial Al alloys AA7018 and RDE40 were selected. Gas tungsten arc welding in continuous current, pulsed current and arc oscillation mode were applied to weld the base materials. The influence of Sc containing fillers have been studied and compared with the commercial filler material. Mechanical and metallurgical characterisation were carried out in the EQZ. Intergranular corrosion in EQZ was studied according to ASTM G 110-92. Results reveals that RDE40 with low solute contents showed wider EQZ but relatively better corrosion and mechanical properties compared to AA7018 EQZ. Gas tungsten arc welding in pulsed and arc oscillation mode fusion boundary region exhibits better corrosion and mechanical properties compared to continuous current mode welds. Addition of Sc to the AA5556 filler combined with pulsed mode resulted in elimination of EQZ, better corrosion and mechanical properties compared to welds made with conventional AA5556 filler and also the presence of Sc within the EQZ so called unmixed zone has been observed.

Epoxy encapsulant as serendipitous dosimeters during radiological/nuclear events

The radiation response of a smart chip (embedded integrated circuit) module has been reported earlier using the technique of optically stimulated luminescence (OSL). It was found that a smart chip module could be used to evaluate the personnel exposure in the accident dosimetry range. Through subsequent experiments, the radiation sensitivity of the chip module was traced to the epoxy encapsulant provided to protect the chip from the environment and physical damage and that the radiation sensitivity of the epoxy is due to the silica used as the ‘filler’ for controlling the thixotropic properties of the epoxy used for ‘glob top’ or ‘dam-and-fill’ encapsulation. It is desirable to retain the ability to use the smart chip as an accident dosimeter without requiring a modification of standard manufacturing process for which an infrastructure already exists to avoid additional costs. For this reason, we have investigated commercially available filled and unfilled epoxies both as received from the manufacturer and compared their response with epoxies to which commercial fillers are added. In this work we investigate the OSL response of various epoxies commonly used for potting of electronic circuits with and without various filler materials for their potential to be used as a casualty dosimeter in the exposure range of 0.5–10 Gy.

Paper mill sludge as a component of wood adhesive formulation

Abstract Three major types of paper mill sludge, primary sludge (PS), secondary sludge (SS) and de-inking paper sludge (DPS) were characterized and evaluated as adhesive fillers. Plywood panels were made of formulations with phenol formaldehyde (PF) and sludges. Panels with PF/PS and PF/SS formulations had higher dry and wet shear strengths than those made with PF/Cocob® formulation. All wood failure values were comparable. Dry and wet shear strengths of the panels with PF/DPS formulation were comparable to those of the PF/Cocob® panels (with Cocob® as a commercial filler), but the former displayed a much lower wood failure value. Owing to this fact and its high ash content, DPS was not evaluated further as a potential component of adhesive formulations. Compared with SS, PS resulted in higher dry and wet shear strengths and higher wood failure values. However, granular SS was easier to disperse into the resin component than fibrous PS, and the PF/SS formulation was more easily dispensed on aspen veneer sheets than the PF/PS formulation. SS alone displayed adhesive properties with 0.87 MPa of dry shear strength, but PS alone did not exhibit any bond strength. PS and SS were further evaluated for their general thermal behavior and major functional groups using differential scanning calorimetry and Fourier transform infrared spectrometry, respectively.

Joining of superalloy Inconel 600 by diffusion induced isothermal solidification of a liquated insert metal

The effect of process variables on the microstructure of transient liquid phase bonded IN 600 using a commercial filler alloy was studied. Microstructural examination of bonded specimens showed that isothermal solidification of the liquated insert occurred during holding at the joining temperatures. In cases where the holding time was insufficient for complete isothermal solidification, the residual liquid transformed on cooling into a centerline eutectic product. The width of the eutectic decreased with increased holding time and an increase in initial gap width resulted in thicker eutectic width in specimens bonded at the same temperature and for equivalent holding times. In addition to the centerline eutectic microconstituent, precipitation of boron-rich particles was observed within the base metal region adjacent to the substrate–joint interface. Formation of these particles appeared to have influenced the rate of solidification of the liquated interlayer during bonding. In contrast to the conventional expectation of an increase in the rate of isothermal solidification with an increase in temperature, a decrease in the rate was observed with an increase in temperatures above 1160 °C. This could be related to a decrease in solubility of boron in nickel above the Ni–B eutectic temperature.

Building Your Practice with Fillers

Introduction: The objectives of this article are to (1) evaluate the popular fillers as practice builders and (2) outline a typical practice builder program for the surgeon. Methods: Information was gained from a search of the literature, 25 years of clinical experience, and interviews as well as a survey of 35 physicians to determine present surgeon techniques. Fillers were graded 1–5 to qualify as an income generator (with 5 being the highest). Results: Autologous fat scores were higher than that of the other fillers, although any filler could be in a practice-builder program. All bioresorbable fillers will need additional fill to obtain the desired results, but fat has an added benefit of some eventual permanence. When more than 5 mL of filler is needed, fat has also has the most reasonable cost. The commercial fillers will cost $93 to $200 per milliliter. Autologous fat, even with the added cost of anesthesia, disposables, and a minor operating room setup, will be more economical for the patient in amounts greater than 5 mL. When the surgeon can charge less for the filler itself, there is more room for a fair professional fee. There are 3 instrument systems available for fat transfer on the market. These systems accomplish different goals; thus, all have their position in the marketplace. These systems include the TissuTrans, the LipiVage, and the Coleman type modified liposuction instruments. The latter includes all micro-cannula-type instruments. Since it has been established that fat trauma during transfer should be minimized, the system and technique that will give the least amount of trauma to the fat cell should be the first choice. Conclusions: There is now a resurgence of interest in autologous fat because of the very high costs of commercial substances. Because of public acceptance and the availability and cost of economical raw goods, autologous fat can be a key filler in a practice-builder program. To have a successful goal-oriented program, one must use lipocyte-friendly instruments and put a great deal of effort into training the staff. The program must be organized, advertised, marketed, and reviewed at specific intervals for improvement. NOTE: When speaking of the best practice-builder filler, it is assumed that the surgeon will follow ethical guidelines in choosing the best filler for the patient, not just the filler that fits his or her program.