Search

In this paper, data are presented on the microstructure and superplastic deformation mechanics of an aluminum alloy, 2024, containing 10 vol% SiC particles. The material was fabricated by spray atomization and codeposition. The properties were studied after pretreatment by isothermal hot compression and isothermal hot forward extrusion (extrusion ratio 10.0). The experimental results show that the strain-rate sensitivity index (m-value) is 0.48 and the limit elongation (the elongation at fracture) is 345 % during superplastic uniaxial tension. The optimum conditions for superplastic behavior are 753 K of deformation temperature and 1.0 × 10−3 s−1 of initial strain rate. Superplasticity may result from the fine grain size and the well-distributed SiC particles during superplastic uniaxial tension. Moreover, the simple and convenient pretreatment used in this paper is easily applied to industrial practice. [ABSTRACT FROM AUTHOR]

This paper presents a geometrically nonlinear analytical model of the flexible cylindrical rim of a deployable precision large space antenna reflectors made of shape-memory polymer composites. A nonlinear boundary-value problem for the rim in the deformed (folded) configuration is formulated and exact analytical solutions in elliptic functions and integrals describing the deformation modes of the rim are obtained. Exact analytical solutions based on the geometrically nonlinear model are obtained and can be used to determine preliminary geometric dimensions and optimal shape of the flexible rim along with the estimation of the accumulated energy. [ABSTRACT FROM AUTHOR]

In this paper, quaternized β-cyclodextrin-montmorillonite composite (QCD-MMT) was obtained and absorption properties of Cr(VI), methyl orange and p-nitrophenol were studied. QCD was prepared by 2,3-epoxypropyltrimethylammonium chloride and β-cyclodextrin (β-CD). QCD-MMT was obtained by reaction between QCD and montmorillonite suspensions, which could be attributed to the montmorillonite cation ion exchange properties. β-CD cavities of this composite were expected to capture organic molecules through inclusion, while montmorillonite units acted as the adsorption sites for metals. QCD-MMT was characterized by FT-IR, elemental analysis, XRD, SEM-EDX, and TGA. Adsorptions of Cr(VI), methyl orange, and p-nitrophenol were highly dependent on adsorbent dose, initial concentration, temperature, contact time, and pH. Adsorption kinetics of Cr(VI), methyl orange, and p-nitrophenol followed the pseudo-second-order model. Meanwhile, adsorption of Cr(VI) fit better in the Freundlich model, inferring a multilayer adsorption, while the adsorption of methyl orange and p-nitrophenol fit better in Langmuir model, inferring a monolayer adsorption. Thermodynamic analysis showed that the adsorptions were all endothermic process and could be spontaneous at given temperature range, except for Cr(VI), of which adsorption should be at much higher temperature. Overall, QCD-MMT exhibited potential for practical applications in the treatment of both metal ions and organic pollutants. [ABSTRACT FROM AUTHOR]

This paper outlines a sol-gel method for the synthesis of TiO/CdS composites with different CdS concentrations for use in supercapacitor applications. Composite electrodes of TiO/CdS containing zinc (0.25, 0.5, 0.75, and 0.1 M) and sulphide (0.5, 0.1, 1.5, and 2 M) in a 1:2 molar ratio were prepared and are labelled TC1, TC2, TC3, and TC4, respectively. The X-ray diffraction patterns displayed peaks for TiO and CdS. A gradual change in morphology from rod like to spherical as the CdS content increased was observed using FE-SEM and confirmed by TEM analysis. Furthermore, the electrochemical properties of all prepared electrodes were analysed using techniques such as cyclic voltammetry (CV), galvanostatic charge-discharge (GV), electrochemical impedance spectroscopy (EIS), and cycle life testing. Among the studied electrodes, CV analysis of TC1 indicated a capacitance of 1296 Fg at a low scan rate of 10 mVs, whereas GV analysis showed the value to be 1320 Fg at a scan rate of 10 Ag. Also, the significant increase in the energy density and power density of the TC1 electrode may open a new path to supercapacitor applications. The improved electrochemical performance of TC1 can be largely attributed to its increased BET parameters, rod-like morphology, and low charge transfer resistance. Furthermore, an asymmetric capacitor (ASC) was fabricated using the TC1 electrode as the cathode material and activated carbon as the anode. The fabricated ASC had a capacitance of 685 Fg at a scan rate of 10 Ag with a high energy density of 219 kWh kg. The repeatability test results imply that even after 500 cycles of operation, the as-fabricated ASC exhibits 95% capacitance retention. Additionally, on charging, the as-fabricated ASC has the ability to glow green in a light-emitting diode. Therefore, the TC1 electrode is a suitable cathode material for next-generation supercapacitors in high-energy density storage systems. Graphical Abstract: [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced polymer composite laminates are anisotropic, inhomogeneous, and mostly prepared in laminate form before undergoing the finishing operations. The edge trimming process is considered as one of the most common finishing operations in the industrial applications. However, the laminate surface is especially prone to damage in the chip formation process, and the most common damage mode is burrs. Burrs may increase cost and production time because of additional machining; they can also damage the surface integrity. Many studies have been done to address this problem, and techniques for reducing burr size in material removal process has been the focus of the research. Nonetheless, the combined effects of the cutting edge radius and the fiber cutting angle on the burr formation have seldom been conducted, which in turn restricts to find out the mechanism of burr formation. The purpose of the present paper is to study the particular mechanism that leads to burr formation in edge trimming of CFRP laminates and investigate the effects of fiber cutting angle and cutting edge radius on burr formation. The results indicate that the burrs are prone to form in the fiber cutting angle range of 0° < χ < 90° when a large cutting edge radius of the tool is used for both milling and drilling of CFRP composites. [ABSTRACT FROM AUTHOR]

This paper presents the tensile response of thin-walled composite tubes with multi-axial fibre architecture. A hybrid braid-wound layup has the potential to optimise the composite tube properties, however, stacking sequence plays a role in the failure mechanism. A braid-winding method has been used to produce stacked overwound braid layup [(±45°/0°)/90°]. Influence of stacking sequence on premature failure of hoop layers has been reported. Under tensile loading, a cross-ply composite tube with the alternate stacking of hoop and axial fibre show hoop plies splitting similar to the overwound braided composite tube. However, splitting has been restricted by the surrounding axial plies and contained between the adjacent axial fibre tows. This observation suggests hoop layers sandwiched between braid layers will improve structural integrity. A near net shape architecture with three fibre orientation in a triaxial braid will provide additional support to prevent extensive damage for plies loaded in off-axis. Several notable observations for relatively open braid structures such as tow scissoring, high Poisson's ratio and influence of axial tow crimp on the strain to failure have been reported. Digital Image Correlation (DIC) in conjunction with surface strain gauging has been employed to capture the strain pattern. [ABSTRACT FROM AUTHOR]

This paper describes the morphological, thermal, and tribological characteristics of poly(vinylidene fluoride) (PVDF)-based composites dispersed with nanosized TiO (nano-TiO) particles. PVDF/nano-TiO composites with different nano-TiO loading (~40 wt%) were prepared via a dry-mixing and uniaxial hot-press molding technique. The incorporation of nano-TiO led to changes in the crystal structure of the PVDF, as characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. The uniform distribution and good interactions of the composites were confirmed by scanning electron microscopy and energy-dispersive spectrometry. The frictional performances increased with the amount of nano-TiO owing to the preferential formation of a nonpolar α-phase crystal and the reduced viscoelastic characteristics of the PVDF. The PVDF/nano-TiO composite with 30% loading exhibited the best frictional performance (a staticfriction coefficient of 0.23 and a kinetic-friction coefficient of 0.17), which is comparable to that of the composite prepared via a costly, environmentally unfriendly wet-mixing technique. Furthermore, the taber abrasion resistances were comparable to that of commercialized ultra-high-molecular-weight polyethylene (UHMWPE), indicating the effectiveness of PVDF/nano-TiO hybridization. [ABSTRACT FROM AUTHOR]

This paper outlines the preparation and characterization of chitosan (CS) composites reinforced with mechano-chemically activated fly ash (MCA-FA). A series of composite films was prepared by solution casting method with varying filler content. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses showed good compatibility between the CS matrix and MCA-FA. The surface roughness and irregularity in shape of MCA-FA resulted in its efficient mechanical interlocking with the polymer matrix. This, in turn enhanced the mechanical properties of these composites. All the composite films exhibited a higher tensile strength and a lower percentage of elongation-at-break compared with the pure CS film. The highest tensile strength was observed for the composite films with 1 wt% of filler loading and the reduction in the tensile properties at higher filler loading was due to agglomeration of filler and polymer-filler interface debonding. The tensile strength data were analyzed using Nielsen and Pukanzsky models to understand the interface formation and polymer-filler interactions. Thermal properties showed a marginal improvement due to the incorporation of MCA-FA. Overall, this study indicates that MCA-FA could be used as value added filler in polymer matrix composites. [ABSTRACT FROM AUTHOR]

This paper presents the fire resistance behaviour of partially encased in concrete ultra shallow floor beams (USFB) using numerical analysis method based on material specifications of the EN1994-1-2. Investigating the behaviour of USFBs under elevated temperatures is crucial in determining their fire resistance and evaluating their overall performance in contemporary construction. Even though the manufacturing company provides fire resistances for USFBs based on EC4-1-2 procedures, their response to elevated temperature effects remains up to date neither well documented nor clearly understood. The analyses involved two different beams of span 5 m and 8 m respectively, as specified by the manufacturer. Analysis results showed that such beams, when unprotected, experience severe temperature gradients if exposed to fire, as the lower flange still remains unprotected in contrast to the concrete encased part of the cross-section. As it was anticipated, the moment capacity governs the fire resistance of the beams and the load factor highly effects the elevated temperature behaviour. In addition, the loss of the lower flange, which develops high temperatures, is not compensated by the web and consequently the moment capacity ultimately depends on the temperature of the lower flange. Results also suggest that simulated beams sustained the applied load for approximately 40 min of exposure to the standard fire. [ABSTRACT FROM AUTHOR]

In a series of papers published recently, we clearly demonstrated that the most important factor governing the thermal conductivity of epoxy-AlO composites is the backbone structure of the epoxy. In this study, three more epoxies based on diglycidyl ester-terminated liquid-crystalline epoxy (LCE) have been synthesized to draw conclusions regarding the effect of the epoxy backbone structure on the thermal conductivity of epoxy-alumina composites. The synthesized structures were characterized by proton nuclear magnetic resonance (H-NMR) and Fourier-transform infrared (FT-IR) spectroscopy. Differential scanning calorimetry, thermogravimetric analysis, and optical microscopy were also employed to examine the thermal and optical properties of the synthesized LCEs and the cured composites. All three LCE resins exhibited typical liquid-crystalline behaviors: clear solid crystalline state below the melting temperature ( T ), sharp crystalline melting at T , and transition to nematic phase above T with consequent isotropic phase above the isotropic temperature ( T ). The LCE resins displayed distinct nematic liquid-crystalline phase over a wide temperature range and retained liquid-crystalline phase after curing, with high thermal conductivity of the resulting composite. The thermal conductivity values ranged from 3.09 W/m-K to 3.89 W/m-K for LCE-AlO composites with 50 vol.% filler loading. The steric effect played a governing role in the difference. The neat epoxy resin thermal conductivity was obtained as 0.35 W/m-K to 0.49 W/m-K based on analysis using the Agari-Uno model. The results clearly support the objective of this study in that the thermal conductivity of the LCE-containing networks strongly depended on the epoxy backbone structure and the degree of ordering in the cured network. [ABSTRACT FROM AUTHOR]

Sandwich structures are state of the art for construction of lightweight structures with high mechanical load capacity. Beside established core materials like foams, honeycombs or wood, napcore material is an interesting option when economic production costs or the possibility to integrate extra functionality are criteria in addition to specified mechanical values. Napcore material is made from a two-dimensional resin-impregnated knitted fabric that is shaped into a threedimensional nap structure and stabilized by the cured resin matrix. In this paper the mechanical behavior under low velocity impact loads of sandwich structures made with napcores from aramide textile and phenolic resin is investigated and compared with components containing honeycomb cores. [ABSTRACT FROM AUTHOR]

In this paper, laser cladding of Ti-6Al-4V wire and WC/WC powder to produce metal matrix composite clads with a high ceramic reinforcement and a wider clad width was investigated. Taguchi design of experiments and multiple regression models were used to support this. Single clad deposition of Ti-6Al-4V wire and WC/WC powder was made on a Ti-6Al-4V substrate using wire and powder co-feeding systems. Clad samples were made at varying processing parameters using L orthogonal experimental matrix data. The clad geometries (height and width) and the weight, obtained using a Talysurf CLI 1000 surface profiler and a weighing scale with a sensitivity of 0.0001 g, were presented and analysed. The results showed that a process condition of 1800 W laser power, 300 mm/min traverse speed, 700 mm/min wire feed rate and 30 g/min powder feed rate produced the composite clads with the highest reinforcement fraction of 76 ± 1 wt%, clad height of 1.57 ± 0.03 mm and clad width of 3.91 ± 0.05 mm. This process condition resulted in a clad with the highest signal to noise ratio of 37.67 for the WC/WC reinforcement and the geometrical aspect ratio ( H/ W) of 0.40 which lies within the range of 0.42 ≥ ( H/ W) ≥ 0.13 to prevent the formation of inter-run porosity in deposited overlap clads. The multiple regression model obtained was able to predict the values of the output characteristics with an accuracy of 92 %. The method employed in this study could be easily implemented when other different materials are investigated to result in the optimisation of the process with fewer experimental runs. [ABSTRACT FROM AUTHOR]

Keratin/cellulose cryogels were successfully fabricated using chicken feathers (CF) and cardboard (C) from environmental waste for the first time, to be exploited in oil/solvent absorption. The keratin/cellulose-based composites were obtained by combining the dissolution of CF and C waste in 1-butyl-3-methylimidazolium chloride (Bmim−Cl+) ionic liquid green solvent via regeneration, simply by the freeze-drying method. The characterization analysis of the synthesized keratin/cellulose-based composites was performed using Fourier transform infrared spectrometry, X-ray diffractometry, scanning electron microscopy, and thermogravimetry. The as-prepared cryogel can absorb various oils and organic solvents. Moreover, its sorption capacity can reach up to 6.9–17.7 times the weight of the initial cryogel. This kind of CF/C cryogel revealed good and fast absorption efficiency. It could also be reused by simple absorption/distillation and absorption/desorption methods. Through the kinetic analysis, it was found that the pseudo-second-order model was more appropriate for the keratin/cellulose cryogel oil absorption process. Besides, owing to its low cost, good absorption capacity, and excellent reusability, this cryogel has potential for spill cleanup of oils and organic solvents. [ABSTRACT FROM AUTHOR]

Buckling and postbuckling solutions to circular delamination constrained by transversal restoring forces, which occur extensively in stitched or woven composites with three-dimensional (3D) reinforcement, are obtained by using von Karman's geometrically nonlinear thin plate theory by means of Taylor's series expansion. The through-thickness tows are assumed to provide continuous and linear restoring tractions, opposing the deflection of the annular delaminated region adjacent to a penny-shaped crack. When the end of the delaminated layer is clamped, and the deflection is permitted in the positive direction of the z-axis only, there exists a characteristic delamination radius a* for initial buckling. In the case that the initial delamination radius a0 exceeds a*, it will consist of waves whose sizes decrease gradually, as they are apart from the delamination center with larger distances, and will usually not span the whole crack region. Therefore, buckling profiles can be divided into two types: (1) lacking contact phenomena between the delaminated layer and the base plate; (2) having contact surfaces inside the delamination region. In this paper, growth laws of buckling, postbuckling and growth of delamination at lacking contact surface are discussed. The corresponding stability of the delamination growth under fixed boundary load is studied, and the dependence of stable scope upon the fracture toughness of the composite and the elastic constant of bridging fiber is summarized. It follows from the analysis that bridging can increase the load-bearing capacity of composite structure, improve its mechanical performances and restrain the growth of delamination. [ABSTRACT FROM AUTHOR]

Thermal conductivities of carbon/carbon fiber composites with inhomogeneous interphase are studied in thtis paper. The inhomogeneous interphase is modeled approximately as a multilayered structure consisting of many thin layers having homogeneous properties, and close-formed solution of the effective conductivities of the composites is obtained by using the Mori-Tanaka mean-field concept. [ABSTRACT FROM AUTHOR]

This paper presents a method for greatly enhancing the electrical conductivity and electromagnetic interference shielding effectiveness of short conducting fiber filled polymers. This method involves the addition of a small proportion of metal particles as a second filler to the fiber polymer-matrix composite. The key to the method is that the metal particles melt during the composite fabrication, so that the metal electrically connects the metal-coated carbon fibers to a certain degree, thereby resulting in a partially connected three-dimensional network. By adding 2 vol% tin-lead particles to 20 vol% short nickel-coated carbon fiber filled polyether sulfone, the electrical resistivity was decreased by a factor of 2000, while the shielding effectiveness at 1 GHz was increased from 19 to 45 dB. No such improvement was found for the same volume fraction of tinlead particles added to an uncoated carbon fiber composite. This difference is due to the superior wetting of solder with nickel compared to that of solder with carbon, as shown by contact angle measurements. [ABSTRACT FROM AUTHOR]

Fabrication of composite photocatalysts that provide an easy charge transfer mechanism to enhance the photocatalytic activity is a promising approach for the removal of organic contaminants from the water bodies. In this series, for the first time, we have decorated Ni, Pt, and Pd on the surface of hydrothermally synthesized Cu-doped biphasic Bi2O3. The synthesized composites were analyzed using advanced characterization techniques to uncover the physicochemical properties of the materials. The XRD results revealed well crystalline nature of the materials with enhanced particle size as compared to binary composite. The optical analysis showed the improved optical characteristics of ternary composites. The photocatalytic activity was tested against the RhB and observed the ternary materials with enhanced activity when compared with the binary composite and 5 wt% was the optimum loading of the metal on the surface of Cu- doped Bi2O3. Pd decorated samples showed the highest photo removal of RhB where complete mineralization of dye is achieved only in 50 min which is ascribed to the increased absorption and reduced reunion of charge carriers. The effect of pH of the reaction medium and the role of reactive oxygen species were also examined. In the acidic medium, complete degradation of dye is achieved in 10 min only and holes are found prominent active species for the degradation of RhB. The synthesized materials were stable and could be used many times without significant loss in the photocatalytic activity. [ABSTRACT FROM AUTHOR]

Rare earth elements (RRE), due to their unique magnetic, electrical, and optical properties, are an important group of elements demanded in many application areas from machine technology to the health industry. In this study, new composites were obtained by mixing Erbium oxide (Er2O3), one of the rare earth element oxides, into PCL–PEG blend, which is also an important material group, in different ratios. The characteristic functional groups of the obtained polymer blend/Er2O3 nanocomposites were determined by the ATR-IR, and as the erbium oxide ratio increased, characteristic peaks of the polymers in the blend as well as characteristic signals of the Er–O–Er bond were found. When the thermal behavior of the obtained composites was examined, it was observed that the polymer blend exhibited miscible blend properties and the melting temperature of the polymer blend increased as the Er2O3 ratio increased. In addition, it was determined that the thermal stability of the composite increased significantly. X-ray measurements of composites at room temperature support other measurement results. It was determined that the presence of Er-RRE oxide increased the crystal structure feature in the polymer blend composite. Gamma radiation shielding capabilities of polymer materials containing different erbium ratios were investigated by calculating shielding parameters such as half value layer (HVL), radiation protection efficiency (RPE), and mean free path (MFP). Cs-137 and Co-60 radioactive sources were used as gamma sources. According to the obtained measurement results, Erbium oxide increased the absorption property of the polymer composite material. [ABSTRACT FROM AUTHOR]

In this study, an eco-friendly break pad material using sorghum husk-derived Si3N4 and biochar novel friction modifier was development and characterized. The primary objective of this present study was to replace the already used friction modifier such as alumina and graphite with low-cost eco-friendly sorghum husk biomass-derived Si3N4 and biochar. The Si3N4 was synthesized using thermo-chemical process whereas low-temperature pyrolysis was used to synthesis the biochar. The composites were prepared using a compression molding process followed by post-curing at 120 °C. The results of this study revealed that the addition of Si3N4 as frictional modifier improved the mechanical properties. The highest tensile, flexural, impact, compression, hardness, and lap shear strength of 138 MPa, 192 MPa, 6.7 J/m, 152 MPa, 94 shore D, and lap 17 MPa were noted for composite contain friction modifier of Si3N4 and biochar as 12:8 (N4). The SEM images revealed highly reacted phases of reinforcements as well as toughness improved matrix. Similarly, the composite designation N3 with 10:10 friction modifier produced improved wear resistance of 0.12 mm3/Nm of sp. Wear rate and 0.24 of COF. The optical microscope image of worn surfaces revealed waviness for low Si3N4 constant and flat for higher loading. Moreover the thermal conductivity of Si3N4 rich N5 composite (15:5) records the lowest value of 0.214 W/mK. Thus, the replacement addition of Si3N4 and biochar for alumina and graphite is worth full to maintain the brake pad requirements as well as minimize the environmental impact and improve the circular economy. These eco-friendly brake pads developed using biomass-derived friction modifiers could be used in automotives, electric motors, e vehicles, and bicycles. [ABSTRACT FROM AUTHOR]

Background: This research was done to evaluate the bond strength using two repair methods with lithium disilicate ceramic. Methods: Cojet and clearfil repair methods were used to repair lithium disilicate ceramic. The ceramic was sliced into slices before sintering (30 samples). Vita Ambria (Vita, Zahnfabrik, Germany) ceramic was used, surface-treated with the 2 repair systems and then bonded to composite. Samples are stored, thermocycling was done, and then, shear loading was done until fracture. Bond strength values were collected and statistically analysed. Results: The results showed that the cojet surface treatment showed significantly more bond strength (14.43 ± 1.46 Mpa) than the clearfil surface treatment showing (4.16 ± 1.33) as indicated by paired t-test p ≤ 0.05. Conclusions: Bond strength between composite and the ceramic Vita Ambria is better using cojet surface treatment than using the clearfil system. [ABSTRACT FROM AUTHOR]

In recent years, carbon nanotube (CNT) and metal oxide-based supercapacitor (SC) electrodes have shown remarkable enhancements in their electrochemical properties. In this study, we synthesized a NiO and NiO/3%f-CNT nanocomposite through the direct chemical co-precipitation method. The structural and morphological characteristics of the composite were analyzed using X-ray diffraction, scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscope, and energy-dispersive X-ray spectroscope. Additionally, we evaluated the electrochemical performance through cyclic voltammetry, galvanostatic charge–discharge, and electrical impedance spectroscopy. The NiO/3%f-CNT composite electrode revealed a specific capacitance of 390.74 F/g at 5 mV Na2SO4 aqueous electrolyte. Furthermore, even after 5000 cycles, the NiO/3%f-CNT composite electrode displayed exceptional cyclic stability of 93.5% at 1 A/g, indicating its potential for long-term usage. Overall, our results demonstrated that the chemical co-precipitation synthesized nanocomposite possesses superior electrochemical properties, making it a promising candidate for supercapacitor electrode material. [ABSTRACT FROM AUTHOR]

A struvite/kappa-carrageenan composite is synthesized from an aqueous solution of a polysaccharide and inorganic precursors. The phase and elemental composition, as well as the sizes of composite particles in an aqueous colloidal solution are studied by X-ray phase analysis, X-ray energy dispersive analysis, and dynamic light scattering. It is shown that this promising prebiotic composite is capable of producing diffusion-mobile aqueous colloidal solutions with varying degrees of association of the structural elements, which is convenient for use in biomedicine. [ABSTRACT FROM AUTHOR]

High entropy alloys, especially AlCoCrFeNi, have received much attention in recent years due to their unique properties. Therefore, the study of the various properties of this alloy has been the subject of recent fundamental research. In this study, the electrochemical behavior of zirconia-reinforced AlCoCrFeNi high entropy alloy has been investigated. For this purpose, the OCP and Tafel tests on the samples of AlCoCrFeNi-x wt% ZrO2 (x = 0, 5, 10) were performed in a 3.5 wt% NaCl solution. The SEM images were obtained from the corrosion products. Subsequently, the samples were soaked in the above solution for 24, 48, and 72 h, followed by an impedance test. The results of the Tafel test and the SEM images show that the addition of zirconia up to 5 wt% and 10 wt% to the mentioned alloy decreases and increases the corrosion resistance, respectively. The increase in the FCC phase in AlCoCrFeNi-5 wt% ZrO2 decreased the corrosion resistance. The improvement in corrosion resistance in AlCoCrFeNi-10 wt% ZrO2 zirconia is due to the increase in the ceramic phase and the consistency between the passive layers. The EIS test showed that the addition of zirconia to the AlCoCrFeNi system delays the formation of passive layers by up to 72 h, as it leads to the formation of a rough surface. [ABSTRACT FROM AUTHOR]

In this study, in situ titanium diboride particles were synthesized using boron oxide and titanium oxide to reinforce Al 5083 alloy. Stir casting was used to fabricate this composite. The reinforcement particles were formed in situ inside the melt. The working temperature selected for melting and casting was 80 °C. The effect of cerium oxide, cerium oxide + cryolite, and cerium oxide + cryolite + zirconium additives on the composite was investigated. The results showed that cerium oxide decreased the agglomeration of reinforcing particles in the melt. Cryolite prevented melt oxidation, increased melt flow, and improved the distribution of reinforcing particles in the composite. Zirconium caused the refinement of the structure, decreased the agglomeration of TiB2 particles, and increased the tensile strength of the composite. In addition, the dominant fracture mode in samples modified by cryolite + Zr. CeO2 + cryolite + Zr caused ductile fracture, while in samples modified by CeO2 and CeO2 + cryolite, the brittle fracture was ruling. [ABSTRACT FROM AUTHOR]

The automotive and aerospace industries are replacing monolithic conventional materials with composite materials for making variety of components. The aluminum metal matrix composites (AMCs) are a lightweight high perforce materials. The aluminum matrix composites (AMCs) have high strength to weight ratio as well as high corrosion resistance properties. Many automobile and aerospace components are made of AMCs. The stir casting fabrication technique is mostly used by researchers for the fabrication of aluminum matrix composites. In this research, Al 6063 matrix composites were fabricated by reinforcing varying percentages of TiB2 through the stir casting process. The wt% of TiB2 varied from 1 to 3% in Al 6063. The mechanical behavior of developed composites was analyzed. The result showed that tensile strength, hardness, and impact strength of composites were enhanced by 55.51%, 63.98%, and 28.13% respectively in comparison with the matrix material. [ABSTRACT FROM AUTHOR]

The present work investigates the tribological properties and microstructures of tungsten carbide (WC: 0–30 wt%) and few-layer graphene (FLG: 0.1–0.5 wt%)-reinforced aluminum matrix composites fabricated via the powder metallurgy route. The tribological and mechanical behavior of the produced samples were investigated by the pin-on-disk wear testing machine, micro-Vickers hardness test unit, and compressive test machine. Based on the test results, Al-30 wt%WC-0.3 wt% FLG composite exhibited maximum density (3.35 ± 0.01 g/cm3), hardness (98 ± 1.5 HV), compressive strength (189 ± 4 MPa), and lowest mass loss (0.9 mg), wear rate (1.1 × 10–4 mm3/(Nm)), coefficient of friction (0.14). Compared to pure aluminum, the hardness, compressive strength, wear rate, and friction coefficient of Al-30%WC-0.3%FLG was improved by ~ 250%, ~ 77%, 428%, and ~ 77%, respectively. After 0.3 wt% FLG content, the tribological and mechanical properties were decreased due to the agglomerated graphene nanoplatelets from the scanning electron microscope image of the Al-30%WC-0.5%FLG composite. [ABSTRACT FROM AUTHOR]

In recent years, there has been rising interest in developing green biocomposite for industrial wastewater treatment. In the current research work, the novel hydrogel composite of methylene bisacrylamide (MBA) crosslinked chitosan (CS)-silica (Si)–g–acrylamide (AM)/orange peel (OP) was synthesized and its ability as an adsorbent has been tested through batch and column adsorption of Cr(VI) ion. FT-IR study of MBA crosslinked hydrogel composite sorbent showed the presence of –OH, –C = O, and –COOH groups. XRD and SEM studies represent an amorphous nature and rough surface with a porous structure. Under batch adsorption studies, the optimum conditions for Cr(VI) adsorption were obtained as pH 6, dosage 4 g, contact time 240 min, and metal ion concentration (62.5 mg/L) with high removal efficiency. In addition, the higher R2 values indicate favourability of Freundlich adsorption isotherm and pseudo-second-order kinetics. Column parameters showed a 1-mL flow rate, 100-ppm initial concentration, and 3cm bed height as the optimum conditions to remove Cr(VI) ions from synthetic wastewater. The column kinetic study reveals a better fit of the Thomas model with a higher R2 value. [ABSTRACT FROM AUTHOR]

Buckling is a critical failure phenomenon for structures, and represents a threat for thin shells subjected to compressive forces. The global buckling load, for a conical structure, depends on the geometry and material properties of the shell, on the stacking sequence, on the type of applied load and on the initial geometric imperfections. Geometric imperfections, occurring inevitably during manufacturing and assembly of thin-walled composite structures, produce a reduction in the carrying load capability with respect to the design value. This is the reason why investigating these defects is of major concern in order to avoid over-conservative design structures. In this paper, the buckling behavior a conical structure with 45° semi-vertical angle is numerically investigated. The initial imperfections are taken into account by using different strategies. At first, the Single Perturbation Load Approach (SPLA), which accounts for defects in the form of a lateral load, normal to the surface, has been adopted. Then, the actual measured defects have been applied to the structure by using the Real Measured Mid-Surface Imperfections (MSI) approach. Investigations on cylindrical shells using the first strategy have already shown the occurrence of a particular phenomenon called 'local snap-through', which represents a preliminary loss of stiffness. In order to better understand this phenomenon for conical shells, both the aforementioned techniques have been used to provide an exhaustive overview of the imperfections sensitiveness in conical composite shells. This study is related to part of the work performed in the frame of the European Union (EU) project DESICOS. [ABSTRACT FROM AUTHOR]

A natural carbon from coconut fiber is used as a main composite material of gas diffusion layer (GDL) for fuel cell electrode. The composite comprise of polymer (ethylene vinyl acetate and poly ethylene glycol) and carbon in various compositions. The materials are mixed in xylene and printed using casting method. The composite is coated with polytetrafluoro ethylene (PTFE) to achieve hydrophobic requirement as GDL. The electrical properties of composite were measured by using LCR-meter, the porosity was obtained by immersion method, and the hydrophobic properties were observed by measuring its contact angle. The results show the electrical conductivity of GDL prepared corresponds to its carbon content. The electrical conductivity of GDLs is 22.17, 26.89, 35, 43, and 52 S/m for the carbon composition of 65, 70, 75, 80, and 85 %, respectively. The composite of 80 % carbon content and coated with PTFE contains 74 % porosity and has desired hydrophobic properties revealed from its high contact angle, i.e., 120°. [ABSTRACT FROM AUTHOR]

Miniaturization of a microstrip patch antenna using composite nanosized ferrite material is proposed in this paper. Detailed simulations were performed to analyze the effect of increase in relative permeability of substrate material on physical size and efficiency of a microstrip antenna. An analytical expression for estimation of the effective relative permeability is established here on the basis of the detailed simulation. Composite nano ferrite (MnZnCoFeO + SrFeO) with an average crystallite size of 72 nm was synthesized and characterized for electromagnetic properties. The substrate material was prepared by the co-precipitation method. Matching values of complex permittivity ( ε* = 4.1-0.1j) and complex permeability ( μ* = 3.72-0.28j) up to 1 GHz were obtained from the electromagnetic characterization. Measurement of the resonant frequency of the fabricated antenna validates the derived expression of effective relative permeability. It reduces the error in calculation of resonant frequency from 10% to 1%. Simulation and measurement results also confirm that an antenna fabricated with the above parameters can reduce the patch size by almost 44% and increases −10 dB reflection loss bandwidth over a pure dielectric FR4 substrate. Therefore, we propose here an analytical expression for estimation of effective relative permeability and MnZnCoFeO + SrFeO composite nano ferrites as suitable candidate for a high-bandwidth miniaturized antenna in the microwave frequency range. [ABSTRACT FROM AUTHOR]

The evolution of knowledge and inventions that contributed to the science of materials has been studied. The development of materials science in the ancient world involved the accumulation of intuitive inventions and the development of crafts. The antiquity established natural philosophy ideas about the nature of matter and divided all existent things into organic and inorganic worlds (Democritus, Epicurus, Aristotle). In the early Middle Ages, alchemy was widespread, with an idea of transmuting elements into gold. Although alchemical ideas were erroneous, they brought some benefits, contributing to the development of scientific experiment. The New Times marked the rapid development of fundamental sciences that promoted theoretical and practical materials science. This paper presents a chronology of the most important inventions and scientific concepts in a tabular form. [ABSTRACT FROM AUTHOR]

This paper accounts for the commercial polytetrafluoroethylene (PTFE) based composites, filled with molybdenum disulfide (MoS) and/or bronze particles. Fire loss technique followed by atomic absorption analyses is used here to identify the weight fractions of their constituents. The mechanical properties of the composites are characterized using tensile and hardness tests. The results show that the ultimate strength decreases with the addition of MoS. Friction and wear behaviors of the different types of PTFE composites sliding against 100Cr6 steel ball are investigated under dry conditions using reciprocating linear tribometer. Experimental results show that the addition of MoS in the PTFE-bronze composite reduces the wear of this composite. Its friction coefficient undergoes a sharp increase at the end of the test. Scanning electron microscopy examination shows some micro cracks and flake pieces on its worn surface and an abrasive wear mechanism is identified on the steel counter face using an optical microscope. [ABSTRACT FROM AUTHOR]

This paper deals with the dependence of stress redistribution around an elliptical hole in a composite on viscoelastic properties of the composite components. The results are obtained for composites with elastic and viscoelastic reinforcement. It is shown that the stress on a surface of the hole can change non-monotonically for the case of viscoelastic reinforcement, i.e., there can be maxima on the stress-time diagrams during the lifetime of the composite. [ABSTRACT FROM AUTHOR]

In the paper, 2.5 vol% (TiB + TiC)/Ti composite has been fabricated by in situ casting route. 1-D forging and subsequent multistep rolling in (α + β) phase field are conducted on the as-cast composite and, accordingly, the matrix microstructure is significantly refined, and the distribution uniformity of reinforcements is greatly improved. The tensile properties of the composites with different processing states are tested at room temperature (RT), 600 and 700 °C. The results indicate that thermomechanical processing (TMP) can drastically improve strength and elongation of the as-cast composite both at RT and 600 °C. As tensile temperature increases to 700 °C, the UTSs of the composites gradually reduce while the elongations of the composites are enhanced remarkably after TMP. The degradation in UTS can be related to the matrix softening and interfacial debonding at 700 °C. [ABSTRACT FROM PUBLISHER]

Powder metallurgy processing of aluminum alloy based metal matrix composites (MMC) is realized to be a promising alternative as expected to advance rapidly compared to other conventional methods. This paper reviews the extensive development in metal–matrix composite research works with particular focus on aluminum alloys 2xxx series as metal–matrix particulates processed by powder metallurgy route. Effect of reinforcement materials such as SiC and Al2O3 on the mechanical properties of the composites manufactured through conventional methods and powder metallurgy route are compared and presented. The influence of percentage of reinforcement material on the overall properties of the MMC's as reported by the researchers are presented. Summary on fundamental aspects of manufacturing MMC's via powder metallurgy route, the effect of mechanical properties, tribological properties, and microstructural properties are presented. Eventually, some advantages of powder metallurgy method are mentioned which may substantiate the claim to consider this as a novel method for near net shape manufacturing. [ABSTRACT FROM PUBLISHER]

In this paper, we report the preparation and characterization (morphological, structural, surface, and electrochemical) of multiwalled carbon nanotube (MWCNT)/carbon xerogel (CX) electrodes prepared by mixing. This research proposes the hypothesis that the use of a hydrophilic binder (nafion) and the use of MWCNTs enhance electrode capacitance and conductivity. Electrochemical measurements in 2 M NaCl solution were performed. The advantage of adding multiwalled carbon nanotubes to the array of xerogel-nafion was studied through different electrochemical methods. It was validated that the greater carbon nanotube mesoporosity allows less compaction of the electrode, thus effectively increasing the specific area and therefore capacitance. Furthermore, we observed the increase in electronic conductivity reported in numerous studies, a fact that is true for iR drop measurement cycles in both galvanostatic charging and discharging. The carbon composite proved to be viable for energy storage. [ABSTRACT FROM AUTHOR]

We construct a mathematical model describing thermomechanical interaction between composite structure elements (isotropic particles of the matrix and anisotropic short fibers) and the macroscopically isotropic elastic medium with desired thermoelastic characteristics. At the first stage of this model, the self-consistency method is used to obtain relations determining the elasticity moduli of the composite, and at the second stage, the model permits determining its linear thermal expansion coefficient. The dual variational statement of the linear thermoelasticity problem in an inhomogeneous solid permits obtaining two-sided estimates for the bulk elasticity modulus, shear modulus, and linear thermal expansion coefficient of the composite under study. The calculated dependencies presented in the paper permit predicting the thermoelastic characteristics of a composite reinforced by anisotropic short fibers (including those in the form of nanostructure elements). [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation into the ballistic resistance of ultra-high molecular weight polyethylene (UHMW-PE) composite, and compares its performance against a range of common metallic and composite armour materials. An extensive experimental program was conducted to determine the ballistic limit velocity (V) of UHMW-PE composite against 12.7 and 20 mm fragment simulating projectiles (FSPs) for a wide range of thicknesses. For protection against these projectiles, UHMW-PE composite was found to be consistently more mass efficient than rolled homogeneous armour steel (RHA), high hardness armour steel (HHA), aluminium alloy 5059-H131, and polymer composites reinforced with aramid, glass or carbon fibres. In terms of armour space claim, UHMW-PE composite was found to be less efficient than both steel types and glass fibre-reinforced plastic, though it was comparable to aramid fibre-reinforced plastic, and was more efficient than aluminium 5059-H131 and carbon fibre-reinforced plastic. Scaling effects were observed that showed metals were more effective against smaller projectiles in terms of armour mass required to stop a given projectile kinetic energy. These effects were not observed to the same extent for UHMW-PE composite, giving rise to a higher UHMW-PE mass efficiency against larger projectiles. [ABSTRACT FROM AUTHOR]

The most advanced gas storage cylinders are composed of a high molecular weight polymeric liner and fibre reinforced composite. The goal of this paper is to study in ISO 5660 cone calorimeter the thermal behaviours of carbon fibre/epoxy composite covered by a liner made of polyamide 6 (PA6) or polyurethane (PU). Time-to-ignition, amount and rate of mass loss, heat release rate, total heat release rate and effective heat of combustion were measured and calculated at three irradiance levels (20, 40 and 60 kW m). The main exhaust gaseous species evolution as well as oxygen consumption were also quantified during the thermal decomposition process. The transient temperatures were measured at middle-thickness of composite layer and at composite/liner interface by using K-type thermocouples. Indeed, these technical data play a significant role to choose the adequate liner to be used for full-composite cylinder application. Results show that the liner type has no effect on flaming ignition of exposed composite as well as the temperature profiles within materials. Comparing to PA6, the PU liner presents a faster melting and decomposition rate (i.e. with a lower thermal resistance), a lower heat release rate levels and low major gas (i.e. CO, CO and NO) emission yields (i.e. a lower gaseous product toxicity). Based on the comparison of the fire-to-reaction properties, the PU thermoplastics are recommended to be used as liner to cover gas storage composite cylinder. [ABSTRACT FROM AUTHOR]

Intermetallic composite has been expected to be one kind of high-performance wear material at elevated temperature due to its inherent high hardness and strong atomic bonds. This paper presents the wear behaviors under elevated temperature conditions of NiMo/Mo2Ni3Si intermetallic “in situ” composite. Metallographic observations were carried out with optical microscope and scanning electron microscope. Elevated-temperature wear tests were performed under pin-on-disc mode dry sliding conditions. Results shown that the relative wear resistant property of NiMo/Mo2Ni3Si alloys at 500 °C is over 7 times, and become higher at 550 °C compared with austenitic 1Cr18Ni9Ti stainless steel. The effect of temperature and applied load on elevated-temperature wear resistance of alloy was evaluated. The corresponding wear mechanism is also reported through examining the worn surface, subsurface, and wear debris of the NiMo/Mo2Ni3Si intermetallic alloys which is found to be soft abrasive wear. [ABSTRACT FROM PUBLISHER]

Hydrophilic nature of ligno-cellulosic fibers can affect dimensional stability and interfacial bond strength of wood polymer composites. In this paper, moisture adsorption and absorption behaviour of bio-fiber filled high density polyethylene composites has been reported. Composites were prepared with wood pulp and bamboo flour at varying filler concentration and subjected to moisture adsorption and absorption. The magnitude of moisture absorption and adsorption increased with increasing filler content. Moisture adsorption in wood fiber based composites was higher than bamboo flour but there was no significant difference in their water absorption behaviour. Use of coupling agent exhibited a significant influence on the magnitude of water absorption by the composites. Composites with coupling agent absorbed 25-40 % less moisture as compared to the composites without coupling agent in both filler types. Moisture absorption behaviour in the composites was explained based on the theoretical Fickcian diffusion model. [ABSTRACT FROM AUTHOR]

The effect of TiB2 additions on the structure, phase composition, and mechanical and tribological properties of materials in the Fe–FKh800 system was studied. The introduction of titanium boride additions activated compaction of the iron-based composites through sintering with participation of the liquid phase that emerged with the formation of low-melting Fe–C–B (Tm ~ 1050°C) and γ-Fe–Fe2B–TiB2 (Tm ~ 1162) eutectics and led to a 50–70°C decrease in the sintering temperature of the compacts. Titanium boride additions between 0.38 to 0.74 wt.% provided 20–25% higher bending strength of the 65 wt.% Fe–35 wt.% FKh800 composite with a slight increase in hardness. Metallographic studies, X-ray diffraction, and electron microprobe analysis of the Fe–35 wt.% FKh800–TiB2 materials showed that titanium boride additions promoted a multiphase, microheterogeneous matrix-reinforced composite, consisting of Kh17 chromium steel, double M7C3 and M3C iron–chromium carbides, and complex Me3(CB) carboborides. The influence of TiB2 additions on the wear resistance of the composites subjected to dry friction against fixed diamond wheel particles and ShKh15 steel was studied. The study showed that the abrasive mass wear (Im) of carbide steels decreased from 36.94 to 14.8 mg/km and their linear wear (Il) decreased from 0.197 to 0.079 mm/km with TiB2 additions increasing from 0.38 to 1.48 wt.%. Titanium boride additions ranging from 0.38 to 2.2 wt.% reduced the mass wear rate from 4.9 to 1.9 mg/km in dry friction of the composite against a ShKh15 steel counterface with 50–55 HRC hardness and decreased the friction coefficient from 0.49 to 0.38. [ABSTRACT FROM AUTHOR]

Composite sheets consisting of elongated and aggregated cationically charged precipitated calcium carbonate (PCC) and native microfibrillated cellulose (MFC) were prepared with a wet laying method. The furnishes were prepared with and without an anionic flocculating agent (polyacrylamide) in order to adjust the structure of the sheet. The samples were compressed (densified) in order to determine the particle and microfibrillated cellulose-PCC structure coalescence and densification, as well as its subsequent influence on liquid absorption behavior. The densification affected both the vertical and lateral distribution of PCC, but the flocculating agent enhanced the compression stability and stabilized the sheets against PCC material flow. The differences between the sheets made with and without the flocculation aid affected the absorption of an anionic dye-based fluid ink, which was evident as a higher print density and less print bleeding. The absorption behavior was dependent on the sheet structure, especially on the PCC distribution within the sheets. Finally, the role of MFC on floc structure and floc formation is discussed. [ABSTRACT FROM AUTHOR]

Since the development of the first theories to predict the buckling induced by axial compression in shells sensitive to imperfections, a significant discrepancy between theoretical and experimental results has been observed. Donnell and Koiter are among the first authors demonstrating, for these structures, the relevant influence of the geometrical imperfections on the reduction of the buckling load. Currently, the preliminary design of imperfections sensitive shell structures used in space applications is carried out according to the NASA SP-8007guideline. However, several studies have proven that this guideline leads to over-conservative design configurations when considering the geometrical and material imperfections existing in real cones. Since the pioneer work of Arbocz, alternative methods have been investigated to overcome this issue. Among the different approaches, in this paper, the Single Perturbation Load Approach (SPLA), originally developed byHühne as a deterministic way to calculate the knock-down factor of imperfection sensitive shells, is further studied. Indeed, a numerical investigation about the application of the SPLA to the simulation of the mechanical behavior of imperfection sensitive composite conical structures under axial compression is presented. This study is related to part of the work performed in the frame of the European Union (EU) project DESICOS. [ABSTRACT FROM AUTHOR]

This paper presents the results of a series of tests aimed at investigating the development of shrinkage gradient considering slab samples of different concrete thicknesses and exposed to different drying conditions. For this purpose, two types of solid concrete specimens and two types of composite specimens were considered. Stramit Condeck HP® and PrimForm® profiles were used for the profiled sheeting of the composite samples. A total of twelve specimens were prepared and monitored for a period of four months. The experimental data was then used to further validate a previously proposed theoretical model capable of incorporating the effects of non-uniform shrinkage inside a composite slab. A simplified approach was also proposed to account for the occurrence of non-uniform shrinkage in routine design. [ABSTRACT FROM AUTHOR]

This paper presents an effective methodology for characterizing the mechanical parameters of composites using digital image correlation combined with the virtual fields method. By using a three-point bending test configuration, this method can identify all mechanical parameters of the material with merely a single test. Successful results verified that this method is especially effective for characterizing composite materials. In this study, the method is applied to measure the orthotropic elastic parameters of fiber-reinforced polymer-matrix composites before and after the hygrothermal aging process. The results indicate that the hygrothermal aging environment significantly influences the mechanical property of a composite. The components of the parameters in the direction of the fiber bundle decreased significantly. From the accuracy analysis, we found that the actual measurement accuracy is sensitive to a shift of the horizontal edges and rotation of the vertical edges. [ABSTRACT FROM AUTHOR]

This contribution deals with a computational model for a shape memory alloy fiber composite. Three main topics have been considered within the presented model. First, a 1D fiber model is derived which accounts for all relevant nonlinear material phenomena of shape memory alloys. These are pseudoelasticity in the high temperature range and pseudoplasticity in the low temperature range. The latter is closely connected to the shape memory effect. The constrained and two-way shape memory effect are captured as well. Second, the shape memory fiber model is implemented into the finite element method. Two different structural elements are derived which lead to two different discretization schemes. A non-conform meshing concept and a conform meshing concept are presented. Randomly oriented and distributed fibers are considered. Both schemes are compared within the paper. Third, an $$\hbox {FE}^{2}$$ ansatz is presented. The computational homogenization process makes the detailed description of the complicated fiber-structure on macro-level dispensable. The micro-structure is considered in a representative volume element. It captures the main characteristics of the multi-functional composite. Finally, numerical examples present the capability of the formulation. [ABSTRACT FROM AUTHOR]

Research was conducted to develop, analyze and optimize a novel composite element consisting of a perforated reinforcement sheet embedded in self consolidating fiber reinforced concrete (SC-FRC). Experimental results of the optimized composite showed that SC-FRC and the reinforcement sheet act synergistically, which leads to an enhanced material utilization. The research in this paper focuses only on the reinforcement sheet and its optimization supported by a finite element parametric study. A semi-mechanical model was derived to describe the load bearing capacity of an embedded reinforcement sheet under biaxial loading. The semi-mechanical model is based on the mechanical behavior of an infinitive sheet with centered opening. Direct tension tests of the concrete-steel composite as well as tension tests of the non-embedded sheet were performed to experimentally verify the proposed model. [ABSTRACT FROM AUTHOR]

This paper presents an approach to detect damage in composite laminates. The physical basis of the coin-tap method has been investigated in previous studies. The tap test has the ability to indicate damage such as delamination and disbond in a composite structure due to a localized change of stiffness. The changes in vibration signature may be detected by ears or more precisely by measurement instrumentation. It has been shown that the characteristics of sound radiating from a structure during a tap are changed by the presence of defects in the composite laminate. For structurally radiated sounds, the sound field is directly coupled to the structural motion. Therefore, impact response analysis should be performed. In this study, the radiated sound induced by tap was computed by solving the Rayleigh integral equation. Some damage models were also used to analyze the impact response and acoustic analysis of damaged composite laminates. The predicted impact force and sound pressure histories were compared with tap test data. The effects of in-plane load on the impact force and radiated sound were also investigated numerically. [ABSTRACT FROM AUTHOR]

Composites offer outstanding mechanical properties in combination with a low density. To profit from the full potential of these materials there are still some challenges to meet. Efficient, reproducible, and material appropriate repair is one of them. It requires accurate machining on damaged structures to generate an optimal surface for the following bonded repair. In case of large scale structures, machining has to be done on-workpiece because those structures are not removable. This application requires a flexible, low-weight and cost-efficient machine, but also a system that considers the elasticities of on-work-piece machining setups. Small industrial robots offer high availability and flexibility, low investment costs, and a low weight in combination with a suitable workspace. The general disadvantage of these machines is a low stiffness in addition to the existing elasticities. However, in this application only moderate process forces occur. Furthermore, high system elasticity is expected any way, due to the detachable fixation and the workpiece. Accordingly, in this paper an online, low frequency method for the compensation of tool deviations is proposed to enhance the performance of small robots as on-workpiece milling machines. For a high industrial acceptance, a simple robot model for compensation is chosen, thus the measurement effort is minimal and the method can be integrated into a state of the art robot controller without external hardware. Additionally, a concept for an extended method for deviation compensation is presented which also considers the changing elasticity of fixation and workpiece. [ABSTRACT FROM AUTHOR]