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Samples of composite materials based on BrAMts9-2 bronze with the introduction of the Udimet500 and Inconel625 nickel alloys were obtained by wire-feed electron-beam technology. The studies show that the structures of composites formed during printing, although fairly similar due to the same base of the alloys, have different features due to different combinations of alloying elements. The mechanical properties of the samples with the introduction of up to 15 % of the Udimet500 alloy are higher than those of the samples of the second material. With the introduction of 25 % of a nickel alloy, the strength is higher for the composite material samples with the introduction of the Inconel625 alloy. The microhardness of the samples with the introduction of 5 % of a nickel alloy is identical, the introduction of large volumes of a nickel alloy leads to the implementation of greater hardness in the samples with the introduction of the Inconel625 alloy due to the higher content of refractory materials. Relative elongation after rupture varies insignificantly for the samples of both types.

Electron-beam additive manufacturing with a simultaneous feed of two wires is used to produce Cu/Al composites with different contents of Al-12Si aluminum alloy. The obtained specimens are examined by optical microscopy and X-ray diffraction analysis and tested for uniaxial static tension. The introduction of 25 vol % Al-12Si is found to form a fairly homogeneous structure characterized by Cu dendrites and a small volume fraction of Cu9Al4 and Cu4Al intermetallic compounds on the dendritic cell boundaries. The increase of the volume fraction of Al-12Si in the copper alloy to 33 vol % is accompanied by the formation of Cu9Al4, Cu4Al, and Cu3Al intermetallics and an increase in their volume fraction. In the composite with 33 vol % Al-12Si, the Cu9Al4 phase becomes the main one, thus causing brittle fracture of the specimens without plastic deformation. It is shown that, with an increase in the volume fraction of Al-12Si to 30 %, ultimate strength increases significantly in the copper alloy (up to 695 MPa) and relative elongation decreases (down to 4 %) due to the increasing volume fraction of the brittle CuxAly intermetallic phases. The results of hardness measurements testify that the increase of Al-12Si content in the specimens from 25 to 33 vol % increases their microhardness significantly, namely from 1.38 to 4.35 GPa.

Electron beam additive manufacturing from dissimilar metal wires was used to intermix 5, 10 and 15 vol.% of Ti-Al-Mo-Z-V titanium alloy with CuAl9Mn2 bronze on a stainless steel substrate. The resulting alloys were subjected to investigations into their microstructural, phase and mechanical characteristics. It was shown that different microstructures were formed in an alloy containing 5 vol.% titanium alloy, as well as others containing 10 and 15 vol.%. The first was characterized by structural components such as solid solution, eutectic intermetallic compound TiCu2Al and coarse grains of γ1-Al4Cu9. It had enhanced strength and demonstrated steady oxidation wear in sliding tests. The other two alloys also contained large flower-like Ti(Cu,Al)2 dendrites that appeared due to the thermal decomposition of γ1-Al4Cu9. This structural transformation resulted in catastrophic embrittlement of the composite and changing of wear mechanism from oxidative to abrasive.

The regularities of microstructure formation in samples of multiphase composites obtained by additive electron beam manufacturing on the basis of aluminum alloy ER4043 and nickel superalloy Udimet-500 have been studied. The results of the structure study show that a multicomponent structure is formed in the samples with the presence of Cr23C6 carbides, solid solutions based on aluminum -Al or silicon -Si, eutectics along the boundaries of dendrites, intermetallic phases Al3Ni, AlNi3, Al75Co22Ni3, and Al5Co, as well as carbides of complex composition AlCCr, Al8SiC7, of a different morphology. The formation of a number of intermetallic phases present in local areas of the samples was also distinguished. A large amount of solid phases leads to the formation of a material with high hardness and low ductility. The fracture of composite specimens under tension and compression is brittle, without revealing the stage of plastic flow. Tensile strength values are significantly reduced from the initial 142–164 MPa to 55–123 MPa. In compression, the tensile strength values increase to 490–570 MPa and 905–1200 MPa with the introduction of 5% and 10% nickel superalloy, respectively. An increase in the hardness and compressive strength of the surface layers results in an increase in the wear resistance of the specimens and a decrease in the coefficient of friction.

Model research tests of plastic deformation, fragmentation and flow of aluminum alloy material of Al-Mg-Sc-Zr system under high loaded friction in pair with a steel counterbody of a complex shape and comparison of the obtained result with the structure formed by friction stir welding have been carried out. The conducted studies show that the structure formed by extrusion of the material from the friction zone and its compaction in the channel of the counterbody is, in general, close in structure to the structure formed by friction stir welding of similar material. The distinguishing features of the structure formed in the model experiments on friction include the introduction into the stirring zone of material with deformed large-crystal structure, increased grain size of the stirring zone, the presence of defects and differences in the geometry of the stirring zone.

The structure and properties of conically shaped products made of CuCr1 chrome bronze obtained by wire-feed electron beam additive technology have been investigated. The studies show that the organization of the structure in the samples fully corresponds to the peculiarities of the printing process and heat removal from the samples. The structure is represented by large grains elongated in the direction of heat removal. Chromium in the samples is mainly localized in the form of particles located between the dendrite arms. Near the substrate, intense mixing of the bronze with the substrate material (steel 321) is observed. The mechanical properties of the conical and cylindrical sample parts material are at a fairly close level. The samples are characterized by low values of yield strength, low values of tensile strength and high plasticity. Near the substrate, the mechanical properties of the specimens increase.

Ionic substitutions play important role in the modifications of biological apatites. Recently, the attention has been focused on the co-doping effects on functional properties of apatite based biomaterials. In this research work, the dense samples of fluorapatites, Ca10(PO4)6F2 and Ca8MgSr(PO4)6F2, were produced after sintering at 1250?C for 6 h in air. Structural characterization, carried out with XRD, IR, Raman and SEM, confirmed the formation of dense and homogeneous structure with main fluorapatite and small amount of Ca3(PO4)2 phase. The presented results also demonstrate the stability of structural and mechanical properties of fluorapatites after immersion tests in saline and buffer solutions. The durability of mechanical properties and biocompatibility of the Ca10(PO4)6F2 and Ca8MgSr(PO4)6F2 fluorapatites make these materials highly attractive for biomedical application.

This paper is devoted to using multi-pass friction stir processing (FSP) for admixing 1.5 to 30 vol.% copper powders into an AA5056 matrix for the in situ fabrication of a composite alloy reinforced by Al-Cu intermetallic compounds (IMC). Macrostructurally inhomogeneous stir zones have been obtained after the first FSP passes, the homogeneity of which was improved with the following FSP passes. As a result of stirring the plasticized AA5056, the initial copper particle agglomerates were compacted into large copper particles, which were then simultaneously saturated by aluminum. Microstructural investigations showed that various phases such as α-Al(Cu), α-Cu(Al) solid solutions, Cu3Al and CuAl IMCs, as well as both S and S’-Al2CuMg precipitates have been detected in the AA5056/Cu stir zone, depending upon the concentration of copper and the number of FSP passes. The number of IMCs increased with the number of FSP passes, enhancing microhardness by 50–55%. The effect of multipass FSP on tensile strength, yield stress and strain-to-fracture was analyzed.

This study presents the results of experimental work on the production and examination of samples of laminated polymetallic products made by wire-feed electron-beam additive technology using the technique of controlled filament feeding into the melt bath. The structure of the products based on M1 copper and AMg5 aluminum alloy combines metallic and intermetallic layers with the presence of a gradient transition between the phases. Inside the layers with a transition structure the distribution of intermetallic phases can be of different types. The microhardness values of the different structural constituents of the samples differ by more than a factor of 16. The mechanical properties of the material of the transition layers are characterized by low strength and low plasticity. In the structure of the intermetallic layers and at the boundary between them the formation of defects in the form of cracks and delaminations is observed.

By the atomic-force-microscopy method, the authors have studied the microstructure of coatings from tantalum and its compounds, which were formed on the surface of substrates from stainless steel and microscope slide by reactive magnetron sputtering. It has been established that nanostructured tantalum films are characterized by the cellular structure the size of whose cells depends on the material and the physicochemical properties of the substrate surface.

Novel composite CuA19Mn2/Udimet-500 alloy walls with different content of the Udimet 500 were built using electron-beam double-wire-feed additive manufacturing. Intermixing both metals within the melted pool resulted in dissolving nickel and forcing out the aluminum from bronze. The resulting phases were NiAl particles and grains, M23C6/NiAl core/shell particles and Cu-Ni-Al solid solution. Precipitation of these phases resulted in the increased hardness and tensile strength as well as reduced ductility of the composite alloys. Such a hardening resulted in improving the wear resistance as compared to that of source aluminum bronze.

Multi-pass friction stir processing (FSP) was used to obtain a titanium alloy/copper hybrid composite layer by intermixing copper powder with a Ti6Al4V alloy. A macrostructurally inhomogeneous stir zone was obtained with both its top and middle parts composed of fine dynamically recrystallized α- and β-Ti grains, as well as coarse intermetallic compounds (IMCs) of Ti2Cu and TiCu2, respectively. Some β grains experienced β → α decomposition with the formation of acicular α-Ti microstructures either inside the former β-Ti grains or at their grain boundaries. Both types of β → α decomposition were especially clearly manifested in the vicinity of the Ti2Cu grains, i.e., in the copper-lean regions. The middle part of the stir zone additionally contained large dislocation-free β-Ti grains that resulted from static recrystallization. Spinodal decomposition, as well as solid-state amorphization of copper-rich β-Ti grains, were discovered. The FSPed stir zone possessed hardness that was enhanced by 25% as compared to that of the base metal, as well as higher strength, ductility, and wear resistance than those obtained using four-pass FSPed Ti6Al4V.

In the presented work, the effect of friction stir processing admixing the zirconium tungstate ZrW2O8 powder on the microstructure, mechanical and tribological properties of the AA5056 Al-Mg alloy stir zone has been studied. The FSP resulted in obtaining dense composite stir zones where α-ZrW2O8 underwent the following changes: (i) high-temperature transformation into metastable β’-ZrW2O8 and (ii) decomposition into WO3 and ZrO2 oxides followed by the formation of intermetallic compounds WAl12 and ZrAl3. These precipitates served as reinforcing phases to improve mechanical and tribological characteristics of the obtained fine-grained composites. The reduced values of wear rate and friction coefficient are due to the combined action the Hall–Petch mechanism and reinforcement by the decomposition products, including Al2O3, ZrO2, β’-ZrW2O8 and intermetallic compounds such as WAl12 and ZrAl3. Potential applications of the above-discussed composites maybe related to their improved tribological characteristics, for example in aerospace and vehicle-building industries.

The paper investigated the possibility of obtaining large-sized blocks of C11000 copper on stainless steel substrates via electron beam wire-feed additive technology. The features of the microstructure and grain texture formation and their influence on the mechanical properties and anisotropy were revealed. A strategy of printing large-sized C11000 copper was determined, which consists of perimeter formation followed by the filling of the internal layer volume. This allows us to avoid the formation of defects in the form of drops, underflows and macrogeometry disturbances. It was found that the deposition of the first layers of C11000 copper on a steel substrate results in rapid heat dissipation and the diffusion of steel components (Fe, Cr and Ni) into the C11000 layers, which promotes the formation of equiaxed grains of size 8.94 ± 0.04 μm. As the blocks grow, directional grain growth occurs close to the orientation, whose size reaches 1086.45 ± 57.13 μm. It is shown that the additive growing of large-sized C11000 copper leads to the anisotropy of mechanical properties due to non-uniform grain structure. The tensile strength in the opposite growing direction near the substrate is 394 ± 10 MPa and decreases to 249 ± 10 MPa as the C11000 blocks grows. In the growing direction, the tensile strength is 145 ± 10 MPa.

Dissimilar friction stir processing on CuZn37/AA5056 was performed to study structural and phase evolution of a friction stir zone. Formation of 5–10 μm intermetallic compounds (IMCs) such as Al2Cu was the main type of diffusion reaction between copper and aluminum. Other alloying elements such as Mg and Zn were forced out of the forming Al2Cu grains and dissolved in the melt formed due to exothermic effect of the Al2Cu formation. When solidified, these Zn-enriched zones were represented by α-Al+Al2Cu+Zn phases or α-Al+Al2Cu+Zn+MgZn regions. Eutectic Zn+MgZn was undoubtedly formed the melt after stirring had stopped. These zones were proven to be weak ones with respect to pull-off test since MgZn was detected on the fracture surface. Tensile strength of the stirred zone metal was achieved at the level of that of AA5056.

The microstructure and mechanical properties of alloys of the Al – Si system modified with nanosize tungsten powder in an amount of 0.01 – 0.5 wt.% during casting are studied. The phase composition, the sizes, and the localization of phases in the microstructure of the initial and modified Al – Si alloys are investigated by the methods of optical, scanning, and transmission electron microscopy. The ultimate strength, the elongation, and the impact toughness of the Al – Si alloys are determined before and after modification with nanosize tungsten powder.

The interest in silicon carbide (SiC-based) ceramics and composites as matrix material for nuclear waste immobilization is grown up. Long-term chemical durability and radiation resistance of SiC are important factors for radionuclides immobilization. Advantages of SiC-based ceramics as structural materials in nuclear applications are the high-temperature properties, high density and reduced neutron activation. The use of radiation resistant materials is a strong requirement for safe and environmentally beneficial energy system. The SiC ceramics stability under irradiation for temperatures up to 1273 K is also very important for nuclear power applications. The SiC matrices doped by additives of Cr, Si were fabricated using High Speed Hot Pressing Method. Additives content was in the range from 0.5 to 3 wt %. Microstructural characteristics of silicon carbide ceramics were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and infra-red spectroscopy (IR) methods. The results of microcracking under indentation conditions were revealed the lack of cracks in the SiC ceramics with Cr additives before and after irradiation process. In addition, it was demonstrated that samples of SiC with alloying additives Cr and Si possess high mechanical parameters under γ-irradiation process. The strength of ceramics increases with the uniform and fine-grained structure formation. The modification of phase composition and mechanical properties of the SiC ceramics with Cr and Si additives under γ-irradiation were analyzed for further development of radiation resistant and matrix materials for radioactive wastes immobilization.

Nowadays, the development and research of nonwoven medical fibrous materials based on biopolymers is an area of a great practical interest. One of the most promising methods for producing nonwoven materials with a highly developed surface is electrospinning (ES). In this article, the possibility of efficient sterilization of ultrathin fibers based on polyhydroxybutyrate (PHB) by ozone treatment was considered. The purpose of this work was to select the most optimal morphology of nonwoven materials for medical purposes and to establish the correlation between the supramolecular structure and the physical properties of fibrous materials while under the influence of an ozone sterilization process.

The cavitation erosion resistance of carbide and nitride thick (up to 20 μm) coatings by means of the rotating disk testing method was analysed in the present study. The effect of the coatings composition and mechanical properties on the damage mechanism and material weight loss has been confirmed. Results show that all coated samples under investigation are characterised by lower cavitation wear than that of the uncoated ones. Both nitride TiN, CrN, and carbide CrC coatings significantly improve erosion resistance of the stainless steel samples. The correlation between the evolution of mechanical properties of both nitride and carbide coatings and weight losses has been investigated. The differences in the composition affect the mechanical properties of coatings and, finally, cavitation erosion resistance of tested materials. Furthermore, the CrC coated samples have shown improved elastic behaviour and high resistance to plastic deformation as compared to the CrN and TiN coated ones. Young modulus E and hardness H parameters of coatings exceed those estimated for the reference samples. The higher H/E and H3/E2 coefficients in the case of carbide coatings in comparison with nitride ones and reference samples have been established. CrC thick coatings with the ability to form nanocrystalline structure and higher mechanical parameters demonstrate the best protective efficacy for various anti-erosion applications.

The ionic substitutions play important role in the modifications of the biological apatites. Recently, the attention has been focused on the co-doping effects of additives on the functional properties of apatite based biomaterials. Under a research work for which the results are presented here, the dense samples of fluorapatites: Ca 10 (PO 4 ) 6 F 2 and Ca 8 MgSr(PO 4 ) 6 F 2 were produced after sintering at a temperature of 1250 °C for 6 hours in air. The XRD, IR and Raman spectrometry results show a high crystallinity of the fluorapatite and strontium-magnesium-doped fluorapatites. The results demonstrate the stability of structural and mechanical properties of fluorapatites after immersion tests in saline and buffer solutions. The durability of mechanical properties and biocompatibility of Ca 10 (PO 4 ) 6 F 2 and Ca 8 MgSr(PO 4 ) 6 F 2 fluorapatites make these materials highly attractive for biomedical application.

The highly conserved extracellular domain of the transmembrane protein M2 (M2e) of the influenza A virus is a promising target for the development of broad-spectrum vaccines. However, M2e is a poor immunogen by itself and must be linked to an appropriate carrier to induce an efficient immune response. In this study, we obtained recombinant mosaic proteins containing tandem copies of M2e fused to a lipopeptide from Neisseria meningitidis surface lipoprotein Ag473 and alpha-helical linkers and analyzed their immunogenicity. Six fusion proteins, comprising four or eight tandem copies of M2e flanked by alpha-helical linkers, lipopeptides, or a combination of both of these elements, were produced in Escherichia coli. The proteins, containing both alpha-helical linkers and lipopeptides at each side of M2e repeats, formed nanosized particles, but no particulate structures were observed in the absence of lipopeptides. Animal study results showed that proteins with lipopeptides induced strong M2e-specific antibody responses in the absence of external adjuvants compared to similar proteins without lipopeptides. Thus, the recombinant M2e-based proteins containing alpha-helical linkers and N. meningitidis lipopeptide sequences at the N- and C-termini of four or eight tandem copies of M2e peptide are promising vaccine candidates.

The majority of literature sources dedicated to dissimilar Al-Cu friction stir welding testifies to the formation of intermetallic compounds (IMC) according to diffusion-controlled reactions, i.e., without liquation on the Al/Cu interfaces. Fewer sources report on revealing Al-Cu eutectics, i.e., that IMCs are formed with the presence of the liquid phase. This work is an attempt to fill the gap in the results and find out the reasons behind such a difference. Structural-phase characteristics of an in-situ friction stir processed (FSP) Al-Cu zone were studied. The single-pass FSPed stir zone (SZ) was characterized by the presence of IMCs such as Al2Cu, Al2Cu3, AlCu3, Al2MgCu, whose distribution in the SZ was extremely inhomogeneous. The advancing side SZ contained large IMC particles as well as Al(Mg,Cu) solid solution (SS) dendrites and Al-Al2Cu eutectics. The retreating side SZ was composed of Al-Cu solid solution layered structures and smaller IMCs. Such a difference may be explained by different levels of heat input with respect to the SZ sides as well as by using lap FSP instead of the butt one.

This study compares high-speed laser welding (HS-LW) and hybrid laser-arc welding (HS-HLAW) of AA5059. In both cases, the welding speed of 7 m/min promotes the least Mg evaporation and an over than 95% increase in strength comparing to the strength of the initial alloy. However, the porosity of the HS-HLAW welding joint is minimal (0.02%) and its grain size is finer than that of the HS-LW welding joint. The microhardness of the HS-HLAW is similar to that of the initial alloy, and HS-LW causes an increase in microhardness.

To improve the microstructure, microhardness and wear resistance of the gradient zone, the friction stir processing (FSP) of Fe-Cu bimetal, manufactured by electron-beam additive manufacturing (EBAM), is used for the first time. Analysis of the microstructure of the stir zone showed a completely recrystallized grain structure consisting of supersaturated solid solutions of γ-Fe (≤10.8 at.%) in Cu and Cu (≤16 at.%) in γ-Fe, with a decrease in the grain size more than 98% compared to the untreated sample. After FSP the microhardness increased on average by 50%, and the value of the friction coefficient decreased by 25%.

Interaction between nickel base superalloy ZhS6U used as a friction processing tool for in-situ synthesis of intermetallics in Ti6Al4V and this titanium alloy metal has been studied. Severe abrasion-adhesion wear was localized on the tool’ pin areas while shoulder was protected by mechanically mixed layer. Generation of titanium enriched mechanically mixed layers (MML) on the tool's surface was observed whose chemical and phase compositions corresponded to those of Ti2Ni and Ni4Ti3 intermetallic compounds. Fine-crystalline transition layer (TL) was found below the MML which contained high amount of tungsten in the form of fine MC carbide network. Dissolution of initial M6C carbides and diffusion of their components to the MML where new MC-type carbide network formed after stopping the FSP. The MML fragments detached from the tool surface and then were intermixed with the titanium alloy stir zone.

The extracellular domain of the M2 protein (M2e) and conserved region of the second subunit of the hemagglutinin (HA2) could be used for the development of broad-spectrum vaccines against influenza A. Here we obtained and characterized recombinant mosaic proteins containing tandem copies of M2e and HA2 fused to an artificial self-assembling peptide (SAP). The inclusion of SAP peptides in the fusion proteins enabled their self-assembly in vitro into spherical particles with a size of 30-50 nm. Intranasal immunization of mice with these particles without additional adjuvants induced strong humoral immune response against M2e and the whole virus. Particles carrying both M2e and HA2 induced antigen-specific multifunctional CD4+ effector memory T cells. Immunization provided high protection of mice against the lethal challenge with different subtypes of influenza A virus. The obtained self-assembling nanoparticles can be used to develop a universal influenza vaccine.

The results are presented from experimental studies of the microstructure and phase composition of AK7ch Al–Si alloy with an iron content of 0.4 wt % before and after introducing a modifying mixture based on ultradisperse powders of metal oxides and cryolite into the melt. The formation of three-component phases α-Al2FeSi and β-Al5FeSi is established experimentally. The effect iron has on the crystallization of eutectic mixtures is considered using the phase diagram of the Al–Fe–Si system.

The present paper addresses the problem of identification of microstructural, nanomechanical, and tribological properties of thin films of tantalum (Ta) and its compounds deposited on stainless steel substrates by direct current magnetron sputtering. The compositions of the obtained nanostructured films were determined by energy dispersive spectroscopy. Surface morphology was investigated using atomic force microscopy (AFM). The coatings were found to be homogeneous and have low roughness values (&lt, 10 nm). The values of microhardness and elastic modulus were obtained by means of nanoindentation. Elastic modulus values for all the coatings remained unchanged with different atomic percentage of tantalum in the films. The values of microhardness of the tantalum films were increased after incorporation of the oxygen and nitrogen atoms into the crystal lattice of the coatings. The coefficient of friction, CoF, was determined by the AFM method in the “sliding” and “plowing” modes. Deposition of the coatings on the substrates led to a decrease of CoF for the coating-substrate system compared to the substrates, thus, the final product utilizing such a coating will presumably have a longer service life. The tantalum nitride films were characterized by the smallest values of CoF and specific volumetric wear.

The aim of this paper is to prepare the hydroxyapatite by Ion Beam Assisted Deposition and to investigate in terms of its elemental and phase composition, roughness and in vitro corrosion resistance. The coatings were prepared with and without applying bias on substrate, in order to find the effect of bias on the chemical, structural, morphological and anti-corrosive properties. The biased coatings exhibited Ca/P ratio closer to the value of the stoichiometric HAP (1.67). The phase composition is not affected by the bias evolution. The adhesion of both coatings is still satisfactory for biomedical applications, irrespective of the bias. Hydroxyapatite deposited without bias presented the best corrosion resistance in SBF at 37 °C, probably due to its smooth surface and low porosity. Moreover, this coating proved to have the highest protection ability at the SBF corrosive attack.

The results of an investigation on slip cast and sintered Y 2 O 3 (3 wt%)- stabilized ZrO 2 with additions of 5, 10, 15 wt% Al 2 O 3 are reported. The surface roughness, porosity and density of the samples were measured. The hardness HRc and Hv, fracture toughness K 1C , and friction coefficients were also measured using standard methods. The structural properties of the samples were observed by Scanning Electron Microscopy (SEM). The surface topography was evaluated by means of Chromatic White Light Interferometry using MicroSpy® Topo of FRT Rauheit Kontur before and after tribological tests. The phase and chemical composition were analyzed by X-Ray Diffractometry (XRD), Energy Dispersive X-ray (EDX) spectroscopy, and Raman spectroscopy. Results show that the addition of Al 2 O 3 into YSZ ceramics in the range of 5–10% allows the mechanical and tribological characteristics of the material that can be applied in different mechanical machines for different metallurgical processes to be improved, as well as in chemical engineering or medicine.

The properties of biocomposites based on ethylene–octene copolymers (EOCs) were studied. The mechanical, rheological, and physical properties of the biocomposites were investigated with attention to the filler type, filler content, and grade of EOC. Three grades of EOC with different viscosities were used as the polymer matrices. Two lignocellulosic raw materials were selected as fillers: birch wood flour (WF) and oil flax straw (FS). The effect of the filler variation range (30–70%) on the biocomposites was studied. According to microphotographs, the filler particles were quite uniformly distributed in the polymer matrix. The WF particles had ellipsoid shapes, whereas the FS particles were characterized by cylindrical shapes. The addition of fillers decreased the elongations at the copolymer's break and tensile strengths, but increased the elasticity moduli. The fillers’ hard particles increased the stiffness of the polymer chains in the biocomposites, resulting in declines in elongation at break. The biocomposites with WF had higher tensile strengths and elongations at break than those with FS because the latter were characterized by lower density values than the former. Melt viscosity analysis showed that filler content increased with melt viscosity. The FS biocomposites had higher melt viscosities than the WF biocomposites. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers