Self-reinforced composites (SRCs) are attracting attention due to their advantages in terms of price, lightness, disposal and recycling compared to carbon fiber-reinforced composites. SRC based on UHMWPE can be produced through hot compaction. The fraction of the remelted phase during this process depends on specific parameters, which include temperature and pressure. In this study the estimation of influence of pressure and temperature on the amount of remelted phase is presented. Additionally, the structure of the obtained composites was studied to identify peculiarities and correlations between the processing temperature and the inner structure of SRC.

This paper investigates the impact of residual N-methylpyrrolidone (NMP) solvent content on the physical, mechanical, thermal, and optical properties of molded polysulfone (PSU). A 30 wt.% PSU solution in NMP was prepared, followed by the casting of PSU/NMP films with an average thickness of 250 mu m. Varying NMP content in the films was achieved by adjusting the drying parameters: temperatures from 115 to 210 degrees C and time from 1.5 to 6 h. PSU/NMP sheets were produced from films through compression molding, and samples for various tests were mechanically machined from these sheets. The residual NMP content in the PSU was determined by measuring the weight difference before and after annealing the molded samples at 325 degrees C for 10 min. Specific volume, elastic modulus, flexural strength, flexural deformation, and heat resistance were measured as functions of NMP content, and the chemical structure of the materials was analyzed using IR spectroscopy. The results showed that at low NMP content (0-5 wt.%), an antiplasticizing effect was observed, characterized by an increase in the density, elastic modulus, and strength of the molded PSU/NMP system. However, the heat resistance, as measured by HDT/Vicat test results, decreased across the entire range of NMP content (0-18 wt.%). Although higher drying temperatures accelerated the evaporation of NMP from the PSU, the optical properties and color of the samples deteriorated due to oxidation processes.

In order to examine the influence of the production technique on the performance of hydride-forming multi-principal-component alloys, a series of alloys in the Ti-Zr-V-Nb -Ta-Hf system has been obtained by arc-melting and electron beam melting combined with pendant-drop melt extraction (EBM-PDME). Structure analysis shows that EBM-PDME method ensures the synthesis of single-phase alloys with BCC structure for all studied compositions. During hydrogenation, the complete and reversible BCC to FCC phase transformation with maximum hydrogen capacity up to 2.0 wt% occurs. Mechanical and thermophysical investigations demonstrate high values of tensile strength, plasticity and thermal conductivity, which allow the alloys to be used as materials for membrane hydrogen separation. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

The magnetostriction coefficient and its stress dependence are evaluated in Co- and Fe-Ni- based glass-coated microwires with different character of hysteresis loops and positive and low negative magnetostriction respectively. We found that the stress dependence of the magnetostriciton coefficient, λs, is linear for both families of studied microwires, however a decrease with applied stress is observed for Co-rich microwires with negative magnetostriction coefficient. In contrast, a linear increase of the magnetostriction coefficient with applied stress is observed for Fe-Ni- rich microwires with positive magnetostriction coefficient. Observed results are discussed in terms of influence of internal stresses and short range ordering induced by annealing.

A thermodynamic model was proposed to assess the feasibility of the synthesis of single-phase multiprincipal-component alloy. Based on this model, single-phase TiVZrNbTa equiatomic alloys with body centered cubic (BCC) structure were obtained by arc melting (AM), electron beam melting with pendant drop melt extraction (EBM-PDME) and mechanical alloying (MA). The alloys were characterized by powder X-ray diffraction, scanning and transmission electron microscopy, thermal analysis and mechanical testing. The hydrogenation behavior of the synthesized materials was studied by a volumetric method. It was found that for AM and EBM-PDME alloys a complete BCC-to-FCC structure transformation occurs upon hydrogenation, and hydrogen concentration in the hydrides formed reaches 1.5 HAM (1.6 wt%). MA alloy undergoes partial amorphization with maximum hydrogen absorption capacity of 0.9 wt%. (C) 2022 Elsevier B.V. All rights reserved.

In the present work, mechanical properties of metal-polymer composite membranes for hydrogen separation have been investigated by tensile test and mechanical spectroscopy methods. The membranes were prepared by high-energy ball milling and subsequent thermal pressing of a powder mixture of polyethylene with 10 wt% hydride-forming intermetallic compound LaNi2.5Co2.4Mn0.1. The membranes were then subjected to activation by long exposure in a hydrogen atmosphere. The static tensile test showed a slight decrease in membrane tensile strength after hydrogen activation that may be explained by intermetallic particle embrittlement. Mechanical spectroscopy study reveals a shift of the internal friction peak of the activated membrane by 22 K towards lower temperatures and a small decrease of the activation energy of polyethylene viscoelastic transformation from 144 kJ/mol to 138 kJ/mol. (C) 2021 Elsevier B.V. All rights reserved.

The results of comparative studies of the electrically conductive properties of Co69Fe4Cr4Si12B11 glass coated amorphous microwires obtained during their heat treatment in a conventional furnace and by the Joule heating method are presented. The fully crystallized microwire dramatically changes its electrically conductive properties. We found that the crystallized microwire has a temperature coefficient of resistance, alpha = 315*10(-6) 1/degrees C. The crystallized microwire was used as a reference resistance thermometer under Joule heating for determining the temperature of the microwire as a function of the applied thermal power T(P). This dependence obtained was used to determine the temperature dependence of the resistance R-M(T) of other microwire samples in an amorphous or partially crystallized state of the same series. The proposed method allows to select thermal modes during Joule annealing of microwires and to compare the resistive, magnetic and structural-phase properties of microwires after thermal effects.

TiO2 nanoparticles (NPs), functionalized poly vinyl chloride (PVC) and polysulfone (PSf) were assembled together in different compositions to fabricate composite membranes with potential application in Cr (VI) and antifouling treatment. Here, TiO2 nanoparticles were synthesized via sol-gel process and Poly vinyl chloride chemically altered with 4-amino benzoic acid. Functionalized PVC was blended uniformly throughout PSf matrix rendering the yellowish-orange color and porous structure giving better productivity. TiO2 NPs were studied for optimum concentration to provide the excess charge for Cr (VI) rejection. SEM images revealed the porous finger like structure within the membranes and the molecular weight cutoff confirmed the ultrafiltration nature of the membranes. Composites showed good wetting behavior with contact angle (between 67 and 76°) and swelling behavior (≈50–79%). Cr (VI) aqueous rejection and the key parameters namely pressure, pH, filler TiO2 concentration and BSA protein were studied in detail. Maximum of 87 ± 5% rejection of Cr (VI) was obtained with productivity of 6.5 L/m2h at 100 kPa pressure in acidic medium. While the antifouling experiments indicated incorporation of TiO2 NPs increased the flux recovery ratio, presence of BSA protein in feed solution showed binding effects with Cr2O72− anions. The membranes showed good reusability for continuous 3 cycles maintaining the rejection efficiency above 70 ± 5% at the end of 3rd cycle.

The investigation addresses the impact of stress on soft magnetic and giant magneto-impedance (GMI) of rapidly quenched Fe77.5Si7.5B15, (Co94Fe6)(72.)5Si12.5B15 and (Co94Fe6)(72.)5Si12.5B12.5Nb0.5Cr2 microwires. Differential scanning calorimetry revealed interesting phase stability in the later alloys. The vitrified microwires contained dominant Co and a lean Fe content showed much superior soft magnetic properties and high magnetoimpedance. The alloy microwires incorporated with Nb and Cr manifested lowest coercivity value of 0.034 Oe with a high GMI(max) value of 425% in the as-quenched state. The uniaxial stress applied on the microwires modified the shape of the hysteresis loops and GMI plots. The hysteresis loops showed stress dependence of coercivity based on alloy chemistry, phase stability and consequent magnetostriction. The GMI(max )revealed sensitive change with respect to the applied stress in all the alloy microwires. In addition to GMI(max) interesting features were observed in the GMI profile pertaining influence of stress on the anisotropy field. The anisotropy field shifted systematically in one of the alloy microwires which displayed symmetric dual GMI peaks. The stress was also found to modify the asymmetric characteristics in a microwire. (C) 2020 Elsevier B.V. All rights reserved.

The effect of Gd on the formation of a lamellar structure during ageing of quenched gamma-TiAl based alloys was studied. Ti-47.1Al-1.8Nb-0.5Zr-0.3V-0.001Gd (0.001Gd) and Ti-46.9Al-1.6Nb-0.5Zr-0.5V-0.03Gd (0.03Gd) alloys were quenched from the alpha-phase field and aged at 400-800 degrees C. After quenching, a small amount of Gd2TiO5 particles was found in both alloys. Grain boundary segregation of Gd in the 0.03Gd alloy quenched from the alpha-phase field was detected. The alpha(2)->gamma transformation kinetics with the formation of gamma lamellae was found to be noticeably faster in the 0.001Gd alloy. In addition, an increase in the Gd percentage led to a reduction of the interlamellar spacing for all ageing conditions. The effect of Gd on surface energy and diffusion rate are discussed.

The potential of filter paper as a substrate material and 4-aminophenyl sulfone (APS) as a novel monomer for TFC fabrication is explored for the first time. A novel polyamide selective layer was developed using APS and trimesoyl chloride by interfacial polymerization, whereas the control TFC was prepared by replacing APS with m-phenylenediamine. Formation of the interfacial selective layer was verified by ATR-IR spectra and the stability of the selective surface coatings was discussed by investigating the monomer interaction. Surprisingly, after polymerization, interconnected, cross-linked structure of two monomers was observed. Desalination studies were carried out in FO mode and PRO mode using NH4HCO3 as a draw solution. Maximum of 90% and 95% rejection was obtained for NaCl and Na2SO4 salts with a flux of 2.51 and 2.17 LMH respectively. The separation efficiency of the prepared TFC membrane was compared against the likes of a commercial TFC membrane under the same conditions.

The effect of Gd on the formation of a lamellar structure during ageing of quenched γ-TiAl based alloys was studied. Ti-47.1Al-1.8Nb-0.5Zr-0.3V-0.001Gd (0.001Gd) and Ti-46.9Al-1.6Nb-0.5Zr-0.5V-0.03Gd (0.03Gd) alloys were quenched from the alpha-phase field and aged at 400–800 °C. After quenching, a small amount of Gd2TiO5 particles was found in both alloys. Grain boundary segregation of Gd in the 0.03Gd alloy quenched from the alpha-phase field was detected. The α2→γ transformation kinetics with the formation of γ lamellae was found to be noticeably faster in the 0.001Gd alloy. In addition, an increase in the Gd percentage led to a reduction of the interlamellar spacing for all ageing conditions. The effect of Gd on surface energy and diffusion rate are discussed.

We studied the influence of annealing conditions on magnetic and thermal properties of Finemet-type alloys. The evolution of the Curie temperature, T-c, and the change of heat capacity in the vicinity of this magnetic transformation, Delta C-p(Tc), were investigated using Differential Scanning Calorimetry, DSC. Relaxation of atomic structure of amorphous phase during the annealing was accompanied by an increase in T-c and decrease in Delta C-p(Tc). Two relaxation processes with different mechanisms take place in amorphous state: topological ordering and chemical ordering. The study of the kinetics of relaxation process allows to estimate the apparent values of activation energy of both relaxation processes: 29 and 87 kJ/mol for ribbon, 37 and 112 kJ/mol for microwire. Precipitation of alpha-Fe nanocrystallites in amorphous phase leads to gradual degradation of the T-c peak. The T-c peak reduction is correlated to decrease of the amorphous phase as well as lowering of its magnetostriction. The influence of internal stress on the position and shape of the Curie peak was determined by comparing data for the ribbon-shaped alloys and glass coated microwires. Considerable magnetic softening and giant magnetoimpedance effect under heat treatment is observed in the studied Finemet-type microwires. Changes in magnetic properties after heating are associated with devitrification and stresses relaxation. We also study the influence of internal stresses induced by glass coating on the magnetic properties of as-prepared and annealed microwires. The results confirm the previously made conclusion that changes in the thermal and magnetic properties of Finemet-type alloys during heating are interrelated, since they are reflections of the fundamental characteristics of the material.

Single phase ternary (TiFe)(100)Ni--x(x) alloys were synthesized through high-energy ball milling. Ni solubility in equiatomic TiFe reaches 10 at. %, exceeding the values known from the equilibrium diagram of state and those obtainable by conventional arc melting. The reactivity of mechanically alloyed (TiFe)(95)Ni-5 with hydrogen was investigated in detail by a combination of volumetric and calorimetric methods. The influence of Ni addition on the pressure-composition isotherms and the reaction enthalpies was evaluated. Finally, the hydrogenation behavior was compared with Ni-free mechanically alloyed TiFe and with literature data on different TiFe-Ni alloys. (C) 2019 Elsevier B.V. All rights reserved.

Ternary alloys of general composition (TiFe)(100-x)M-x (M = Co, Nb) have been synthesized from pure metals through high-energy ball milling. The maximum concentration of alloying components allowing formation of single phase TiFe-type compounds has been defined as 2 at.%. The hydrogenation behavior of the mechanical alloys in comparison with the arc-melted ones of the same composition has been studied by a combination of volumetric and calorimetric techniques. Influence of the alloy composition and the synthesis mode on the crystal structure of TiFe and its hydrides has been evaluated. It has been shown that the thermochemical method based on calorimetric titration provides more accurate information about phase transformations in the nanocrystalline metal hydride systems. The obtained results show that the third components slightly affect the hydrogen storage performance of non-equilibrium mechanical alloys in contrast with alloys produced by conventional melting. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

The influence of P on amorphizing ability, as-quenched microstructure, thermo-physical and soft magnetic properties of Fe-rich (i) Fe81B15-xPxSi2Nb1Cu1 (ii) Fe82B14-xPxSi2Nb1Cu1 and (iii) Fe83B13-xPxSi2Nb1Cu1 (x = 0, 2, 4, 6, 8 at%) melt-spun alloys are investigated. The substitution of P improves amorphization of alloys and restricts the formation of hetero-amorphous microstructure for Fe 83 at% ribbons at around (x = 8). The improvement in short range ordering of P containing clusters with varying Fe content has been discussed within the framework of Cluster-Glue atom model and supported by experimental thermal parameters. The optimal P content in Fe-rich alloys in the range of 4 <= x <= 6 delivered favourable thermal properties of high primary and secondary crystallization onset temperature viz; T-x1, T-x2 and temperature span Delta T between these onsets. The P substitution drastically restricts the precipitation of secondary crystallites with reduced enthalpy of secondary crystallisation (Delta H-2) during annealing and favourably assists in attaining maximum magnetic moment during the primary crystallization stage. Moreover, the P substitution (4-8 at%) effects refinement of alpha-Fe nanocrystallites and promotes low coercivity (H-c < 20 A/m) in nanocomposite alloys. On contrary, the P substitution linearly reduces saturation magnetization (M-s) by weakening ferromagnetic exchange coupling and ferromagnetic dilution. An optimal content of 4 at% P offers favourable combination of low H-c and High M-s in both amorphous and nanocomposite state.

In the present work, a new preparation method for metal-polymer composite materials for hydrogen separation which consist of hydride-forming intermetallic compound LaNi5 and polyethylene was developed. According to this technique, the mechanical activation of the initial powder mixtures was employed to provide good interface between the phases. A series of composite membranes with various filler concentrations was synthesized and characterized by X-ray diffraction, scanning electron microscopy and differential scanning calorimetry. The gas transport properties of the obtained materials in relation to H2, O2, N2, CO2 and CH4 were tested. The results indicate that the addition of the hydride-forming intermetallic compound to the barrier polymer leads to significantly improved selectivity with respect to hydrogen. The proposed method can be considered as a promising approach to producing of high performance composite membranes for hydrogen separation.

In our research we studied the influence of bending on the total magnetic losses, the coercivity of minor hysteresis loops and the virgin magnetization curves of amorphous ribbons and microwires prepared from Finemet-type alloy wound on a mandrel of different diameters. The impact of various factors contributing on static and dynamic magnetic properties through bending stress are discussed. The factors pertain to contribution of the magnetoelastic anisotropy, the onset of the strain-induced magnetization, the changes of domain structure and the mobility of domain walls. The major contribution of hysteresis losses as-compared to the eddy-current losses have been observed on changing the mandrel diameter in wound ribbons and wires. The total specific losses of the Finemet-type ribbons are lower than that of microwires at the frequencies ranging from 50 to 400 Hz. Observed difference in the magnetic properties is attributed to different magnetization processes of amorphous microwires and ribbons. A different geometry and magnetoelastic anisotropy of studied materials are most likely to influence the formation of different domain structures. (c) 2018 Elsevier B.V. All rights reserved.

The process of formation of composite powders based on polyphenylene sulfide reinforced with i-Al-Cu-Fe quasicrystals was investigated. High-energy ball milling in a planetary ball mill was applied to produce composites from an initial mixture of polymer and quasicrystalline powders. The influence of ball milling regimes on the structure of both pure polyphenylene sulfide and composite powders was investigated. It was found that using more intense regimes of ball milling leads to a noticeable increase in the size of polymer powder particles because of the agglomeration occurring in milling. Differential scanning calorimetry and X-ray analysis show the results of milling in partial amorphization of polyphenylene sulfide. It was observed that ball milling for 30 min at a carrier rotation rate of 200 rpm is an optimal regime, which, on the one hand, allows one to reach homogeneous filler distribution in the polymer matrix, and, on the other hand, to keep the initial structural and morphological characteristics of the initial polymer.

Solid-state formation method of polyimide (PI) blends based on polyphenylene sulfide (PPS) and fluorinated ethylene propylene (FEP) was elaborated. Recycled thermoset PI powder was used as reinforcements. FEP/PI and PPS/PI blends were obtained by high-energy ball mill without using compatibilizer. PI content in blends was of 25, 50 or 75 wt%. Bulk samples were obtained by sintering at 330 °C during 25 min, with consequent disposition of sample into hot mold between two cold plates and loading the pressure of 20–35 MPa for 10 min. Morphology structure and thermal properties of powder blends were studied by tapped density measurements, DSC and XRD analyses. Thermal and mechanical properties of bulk samples were studied by DMA, hardness measurements and compressive tests. Strong chemical interaction between FEP matrix and PI filler was observed, whereas in case of PPS/PI samples nearly no interaction between components was found. Mechanical tests show that optimum filling degree for PPS/PI system is of 25 wt% PI, whereas in FEP/PI system it is of about 50 wt%.