List of Abstracts

The main features of the method of high-voltage consolidation of powder materials and the resulting advantages and limitations of this method are considered [1]. The method of high-voltage consolidation of powders is effective for the production of refractory composite materials that retain their strength properties at ultrahigh temperatures under aggressive external influences. The short duration of high-temperature exposure in the process of high-voltage consolidation makes it possible to preserve the structural-phase state of the initial powder material in the consolidated compact material. A feature of this method is the high density concentration of the released energy in the area of contacts between powder particles. In this case, the initial state of the surface of powder particles (the thickness and structure of oxide films, the presence of foreign impurities, etc.), the shape of powder particles and their sizes significantly affect the regularities of high-voltage consolidation processes. Along with the characteristics of the powder, the determining factors are: the rate of input of the energy of the electromagnetic field into the powder material, the magnitude and nature of the mechanical pressure acting on the powder compact in the process of high-voltage consolidation. The high energy density in the particle contact zones leads to a local change in the state of aggregation of the powder substance in these zones. Along with the inhomogeneity of powder heating in interparticle contacts, a macroscopically inhomogeneous distribution of the current density in the volume of the consolidated sample is possible. The formation of the structure of a powder material during high-voltage consolidation is determined by processes of different scales occurring at interparticle contacts, in powder particles, in the bulk of the entire sample, and by the mutual influence of these processes.
Further development of this method is associated with a detailed experimental study of thermal processes during high-voltage consolidation of powders of refractory materials using pulsed photometry. Experimental studies of the parameters of high-voltage electrical impulse action in the process of consolidation of high-temperature TaC and HfC powder compositions have been carried out. Registration of the parameters of a high-voltage current pulse and the intensity of thermal radiation of the consolidated powder materials was carried out using a measuring complex developed by the authors. This complex includes: a Rogowski coil with an integrating circuit, which registers the parameters of a high-voltage current pulse; photodiode sensors that register the intensity of thermal radiation, which is transmitted through a special optical waveguide from consolidated powder compacts; systems for triggering and synchronizing the components of the measuring complex. The analysis of the emerging thermal electromagnetic radiation from the surface of the consolidated powder sample in the process of high-voltage consolidation is carried out in the visible radiation range, ranging from λr=650 nm to λr=950 nm.
A criterion has been established that determines the range of optimal technological parameters of high-voltage consolidation for the creation of refractory high-density materials. Possible directions for further research into the process of high-voltage consolidation of powder materials are proposed.

The development of ecofriendly polymer composites reinforced with lignocellulosic fibers have broadly gained attention. This is mostly due to factors such the low cost, abundance, and satisfactory mechanical properties of these natural materials, combined with the urgent need for environmentally sustainable solutions, in addition to a better agro-industrial waste management. In this context, the objective of this study was to evaluate the potential of broom sorghum culms as a reinforcing material in epoxy matrix composites, investigating their behavior in different configurations. The research included the characterization of the culms and the analysis of the mechanical properties of the resulting composites in Izod impact strength, tensile tests, and three-point bending test, comparing two reinforcement configurations: whole culms and longitudinally cut culms. In addition to mechanical testing, relevant physical properties such as density, water absorption, thickness swelling, and moisture content were also determined. Scanning electron microscopy indicated that composites reinforced with longitudinally cut culms showed better adhesion between the reinforcement and the polymer matrix, resulting in superior performance in both mechanical and physical properties compared to composites with whole culms. These findings reinforce the potential of broom sorghum culms as reinforcement in sustainable composite materials, offering a viable and cost effective alternative for applications in sectors that require lightweight, durable, and environmentally friendly materials.

Niobium is a refractory metal of strategic technological relevance due to its high melting point, corrosion resistance, mechanical stability, and broad applicability in aerospace, superconducting, electronic, nuclear, and biomedical-related systems. However, its consolidation by conventional powder metallurgy is usually limited by the need for very high sintering temperatures, which may intensify energy consumption, oxidation, grain growth, and processing costs. In this context, the Cold Sintering Process (CSP) emerges as a promising low-temperature consolidation route, combining high uniaxial pressure, moderate temperature, and a transient liquid phase to promote particle rearrangement, interfacial mass transport, and densification. This study investigates the feasibility of consolidating metallic niobium powders by CSP using phosphoric acid (H₃PO₄) as a transient liquid phase, with emphasis on densification behavior, phase stability, and microstructural evolution. Niobium powders were mixed with 3 and 6 wt.% H₃PO₄ and processed under a constant uniaxial pressure of 450 MPa at 200, 250, and 300 °C for 30 min, using a heating rate of 12 °C/min. The consolidated bodies were characterized by relative density measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The results showed that relative density increased with processing temperature for both acid contents, confirming the strong influence of thermal activation on low-temperature niobium consolidation. Samples containing 3 wt.% H₃PO₄ increased from 85.2 ± 0.6% at 200 °C to 94.0 ± 0.4% at 300 °C, whereas those containing 6 wt.% H₃PO₄ increased from 90.4 ± 0.5% to 94.3 ± 0.3% over the same temperature range. The higher acid content favored densification mainly at 200 and 250 °C, suggesting that a greater amount of transient liquid phase improved particle rearrangement and interparticle contact during the early stages of CSP. At 300 °C, both compositions reached similar relative densities, indicating that temperature became the dominant densification factor under the investigated conditions. XRD patterns confirmed the predominance and preservation of metallic niobium with body-centered cubic structure in all processed samples. No crystalline niobium oxides or phosphate phases were clearly detected within the sensitivity limits of the technique, indicating that H₃PO₄ mainly acted as a transient liquid phase rather than producing detectable crystalline reaction products. Crystallite size values remained within the nanometric range, suggesting that CSP promoted densification while limiting extensive grain growth. SEM observations revealed partial densification, neck formation between adjacent particles, improved interparticle bonding at higher temperatures, and residual porosity distributed throughout the consolidated structures. Samples processed with 6 wt.% H₃PO₄ exhibited enhanced particle contact, consistent with the densification results. EDS elemental mapping showed homogeneous Nb distribution, while phosphorus- and oxygen-rich regions were preferentially located along interparticle boundaries and porous regions, indicating the presence of residual phosphate-containing or oxygen-rich interfacial compounds formed during CSP. Overall, the findings demonstrate that metallic niobium can be successfully consolidated by CSP using phosphoric acid as a transient liquid phase at temperatures far below those required in conventional sintering. The combination of high pressure, moderate temperature, and chemically active liquid phase enabled significant densification while preserving the crystalline structure of Nb. Although complete densification and full microstructural homogeneity were not achieved, the results highlight CSP as a promising strategy for low-temperature processing of refractory metals and provide a basis for further optimization of pressure, temperature, liquid-phase chemistry, and dwell time.

In this study, the sintering behavior of stainless steel 316L components produced by the binder jetting process is examined in detail. The work investigates how the initial distribution of particles and pores, as well as gravity and friction during thermal processing, affects densification, anisotropic shrinkage, and final shape distortion. Dilatometry experiments were performed to characterize shrinkage anisotropy and microstructural evolution at different sintering temperatures. The effects of gravity and friction were further evaluated by analyzing distortion patterns in sintered specimens containing overhangs and tee-pipe connector geometries, which represent practical shapes commonly affected by deformation. In addition to the experimental analysis, this work presents a novel sintering simulation framework for gravity-affected sintering of stainless steel. The model incorporates the Rios-Olevsky-Hryha sintering formulation and a constitutive law that includes material constants accounting for powder packing effects and the delta-ferrite transformation occurring at elevated temperatures. Overall, the study provides both experimental and computational insight into the mechanisms controlling shrinkage, distortion, and microstructural development in binder-jetted 316L components.

The comparison of traditional high-temperature liquid phase sintering and advanced low temperature cold sintering processes will be discussed in the frame of new materials science paradigm and non-equilibrium thermodynamics. At present, two big parts of materials science co-exist: hard-bonded materials (with bond’s energy higher than 1 eV) and soft-bonded materials (with bond’s energy less than 0.1 eV). The convergence of these two energy scales is more than a trend; it is the cornerstone paradigm of Materials Science for now. The New Paradigm treats the "soft" phase not as a secondary filler, but as a structural “director” and energy “dissipator”. The "Hard" world such as ceramics, metals, and semiconductors is driven by enthalpy, processed at high temperatures. The "Soft" world including polymers, liquids, and biological systems is driven by entropy and weak intermolecular forces such as Van der Waals, hydrogen bonding, processed at room temperature. The paradigm represents a breakthrough by utilizing weak bonds, we can create materials that self-assembled into complex 3D architectures that are thermodynamically impossible to reach via traditional melt-processing or hot liquid phase sintering. As for Cold Sintering link, the CSP is the perfect manifestation of this statement. "Soft" chemistry of a solvent to reorganize "Hard" inorganic particles at near-ambient conditions.

If convergence is the "meeting" of two worlds (‘Hard’ and ‘Soft’ bonds), then divergence is the explosive expansion of the state space made possible by that encounter. Cold Sintering (CSP) acts not merely as a consolidation tool, but as a "transport gateway" and an "architectural constructor" for this divergence. Here is why CSP as a realizer of "Impossible" structures. In classical high temperature sintering, high energy 𝑇>1000∘C "erases" the individuality of nanoparticles and the complexity of molecules, homogenizing everything into a standard ceramic. CSP preserves chemical information. This allows for the creation of structures that diverge into an infinite variety of options Mesoporous Hierarchical Systems. The Liquid Phase as a "Decision Space" during the Cold Sintering process, the pressurized liquid phase acts as a medium for self-organization. 

Weak bonds <0.1 eV allow particles to "probe" one another and select the most advantageous configuration (diverging into different symmetries) before the system "freezes" into a solid. This yields structural divergence: from the same starting nanoparticles, simply by varying the "soft" phase (solvent/polymer), we can produce a dense, singlecrystal-like material; a fractal aggregate; a layered "sandwich-type" structure.

Because CSP operates at low temperatures, we can capture metastable phases. This opens the door to materials that exist far from thermodynamic equilibrium. This is divergence in its purest sense—moving away from a single stable state toward a legion of metastable ones, each possessing unique properties (such as anomalous ionic conductivity). CSP allows us to "program" interface boundaries.

The production of powders with extraordinary mechanical and functional properties through rapid solidification, cryomilling, and other techniques necessitates a method to compact them, in order to obtain useful products. Among these methods of consolidation, dynamic compaction stands out because the heating is localized to the surfaces and properties of the individual powders are retained. We summarize the results of our collective experience of thirty years of delivering the controlled and prescribed energy through explosives, gas guns, and high-speed forging machines. The current state of the field, its limitations and potential are reviewed.

The growing demand for environmentally friendly and cost-effective materials has intensified research into alternative reinforcements, particularly natural fibers, for polymer composites; within this framework, this study evaluates the tensile and flexural behavior of polymer matrix composites reinforced with short caranã fibers. The materials were produced via manual processing in accordance with ASTM D638-22 and ASTM D790-17 standards for tensile and flexural testing, respectively, enabling the determination of tensile and flexural strength, Young’s modulus, and strain, alongside statistical validation through one-way ANOVA. The results demonstrated that the incorporation of caranã fibers enhances tensile performance, leading to increased strength and stiffness, whereas under flexural loading a pronounced decrease in both flexural strength and modulus was observed, indicating a distinct mechanical response depending on the type of loading. Overall, these findings suggest that short caranã fiber-reinforced composites represent a sustainable and economically attractive material alternative, particularly for applications where tensile performance is prioritized over flexural resistance.

Powder metallurgy is an important route for producing metal matrix composites with tailored microstructures and enhanced properties. Among consolidation techniques, spark plasma sintering combines rapid heating, short processing times, and applied pressure, favoring densification while limiting grain growth. SS316L composites reinforced with ceramic particles are attractive because they may combine corrosion resistance, toughness, hardness, and ceramic stability [1–2].

This work investigates the influence of yttria-stabilized zirconia on the densification, microstructure, hardness, and corrosion behavior of SS316L composites produced by SPS. Pure SS316L and composites reinforced with 5, 10, and 20 vol.% of 3Y-ZrO₂ were mixed, homogenized, and consolidated under the same processing conditions. The sintered materials were characterized by density, phase composition, microstructure, surface morphology, microhardness, immersion tests, and electrochemical impedance spectroscopy in 3.5 wt.% NaCl solution [3–4].

The results showed that 3Y-ZrO₂ directly affected the densification behavior of the composites. Increasing the ceramic content reduced the relative density and promoted pore formation, especially at higher reinforcement fractions. Microstructural analyses indicated that zirconia was well dispersed within the SS316L matrix, although incomplete densification became more pronounced as the ceramic content increased. Despite this, zirconia addition increased microhardness due to the harder ceramic phase.

From the corrosion point of view, the ceramic content must be carefully controlled. The composite with 5 vol.% 3Y-ZrO₂ showed the best corrosion resistance, suggesting that limited zirconia addition can improve material protection. However, higher zirconia contents increased porosity, compromising the passive layer and favoring localized corrosion. Thus, SPS is a promising route for producing SS316L-ZrO₂ composites, but the balance between reinforcement and densification is essential to optimize performance.

This presentation addresses the effects of electric fields and electric currents on structure evolution in powder and polycrystalline systems at two distinct scales of time and energy delivery. The first is represented by additive manufacturing-assisted spark plasma sintering (AM-SPS), in which current-driven heating operates over minutes and acts on the consolidating powder network as a whole. The second is represented by electro-nano-pulsing (ENP), in which energy is delivered in nanosecond pulses and interacts preferentially with individual defects and internal interfaces. Placing the two approaches side by side clarifies which processing outcomes follow from bulk thermal and electro-mechanical coupling and which require localized, strongly nonequilibrium excitation.

AM-SPS addresses a persistent limitation of field-assisted sintering, namely the geometric constraint imposed by rigid die and punch tooling. In the approach described here, additively formed preforms are consolidated within a sacrificial or partially reactive medium, and the resulting interface between component and surrounding material is treated as a designed element of the process rather than as an incidental feature. Control of this interface governs the transmission of pressure to the component surface, the local current distribution, and the ease of separation after consolidation. A multiphysics framework combining electric current flow, Joule heating, heat transfer, and continuum sintering mechanics is used to relate applied processing conditions to the evolution of density, to shape distortion, and to grain growth. The framework supports the selection of pressure schedules and current profiles for ceramic components whose geometry cannot be produced by conventional uniaxial pressing.

ENP operates on a different premise. Ultra-intense current pulses of nanosecond duration deposit energy faster than can be redistributed by conduction, so that dissipation concentrates at sites of elevated resistivity and elevated defect density. Dislocation cores, grain boundaries, and interphase boundaries therefore receive preferential excitation while the surrounding lattice remains comparatively unaffected. This selectivity provides access to structural states that are difficult to reach through conventional thermal treatment, including modified grain-boundary character distributions, altered grain topologies, elevated retained dislocation densities, and interfacial phases stabilized away from equilibrium. Because the pulse duration, amplitude, and repetition rate can be varied independently, the deposited energy and the associated relaxation pathway can be adjusted with a degree of independence not available in conventional processing, where temperature and time are strongly coupled.

Taken together, AM-SPS and ENP suggest complementary routes for the design of advanced materials intended for applications requiring strength, thermal stability, and structural precision.

This work presents an energy-efficient and ultra-fast sintering strategy (EU-SPS) based on a pressure-less ultra-fast sintering (PLUFS) approach implemented within a spark plasma sintering (SPS) apparatus. The proposed method enables rapid densification of binder-jetted components without the need for a separate debinding step. By integrating the ultra-rapid thermal capabilities of ultra-fast sintering with targeted modifications to the conventional SPS configuration, EU-SPS is designed to process fragile binder-jetted parts while mitigating common metallurgical issues such as carbon contamination and residual δ-ferrite. Finite element method (FEM) modeling grounded in continuum sintering theory was employed to investigate densification kinetics and grain growth during EU-SPS. In addition, a linearized perturbation analysis based on continuum constitutive parameters was used to assess sintering instability and densification inhomogeneity arising from the high heating rates and large thermal gradients intrinsic to the process. Complementary metallurgical characterization was conducted to elucidate the mechanisms governing microstructural optimization in binder-jetted 316L stainless steel. Overall, this work establishes a viable pathway for the rapid post-processing of additively manufactured metals and supports the industrial adoption of binder jetting as a scalable and reliable manufacturing technology.

This work presents the development of composite materials manufactured using additive manufacturing technologies for sustainable applications. Both polymeric and ceramic matrices were used as binding materials, while natural fibers and ceramic particles served as reinforcements. A range of characterization techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), compression testing, and other analytical methods, were employed to investigate the relationships between material composition, processing, and performance.

Particular attention was given to applications involving auxetic structures, filtration, acoustic performance, and dynamic mechanical behavior. The results demonstrate that these applications can be tailored by controlling key material properties such as density, porosity, mechanical strength, and chemical characteristics. In filtration, impact resistance, and noise control applications, increased porosity enhances performance by providing a larger filtration area, greater energy absorption, improved ductility, and higher sound absorption. However, higher porosity generally reduces the mechanical strength of the materials. To achieve an optimal balance between these competing properties, different structural architectures and additive manufacturing parameters were systematically optimized according to the requirements of each target application. 

The search for sustainable materials has driven the development of polymer composites reinforced with lignocellulosic natural fibers, due to their low density, renewable origin, biodegradability, and lower cost compared with synthetic reinforcements [1,2]. Among these fibers, sisal shows high potential for application in epoxy matrices, especially when used in fabric form. However, the hydrophilic nature of plant fibers may impair adhesion with the polymer matrix, limiting the mechanical performance of the composite [3]. In this study, the influence of alkaline treatment with sodium hydroxide (NaOH) on the Izod impact strength of epoxy composites reinforced with sisal fabric was evaluated [4]. The results were analyzed by analysis of variance (ANOVA) and Tukey’s test, showing that the alkaline treatment increased the average impact strength, representing a gain of 16.38%. The statistical analysis confirmed a significant difference between the evaluated groups. Thus, the alkaline treatment proved to be effective in improving the impact response of epoxy/sisal composites, possibly due to enhanced fiber–matrix interfacial adhesion.

The development of lightweight and environmentally oriented materials has increased interest in polymer composites reinforced with lignocellulosic natural fibers for ballistic and military-related applications [1]. In personal protection systems, reducing structural mass is essential to improve user mobility and operational performance [2]. Nevertheless, the use of natural fibers under high-energy impact conditions is still limited by factors such as moisture sensitivity, hydrophilic surface characteristics, and weak adhesion with polymer matrices [3,4]. In this study, epoxy composites reinforced with sisal fabric and sisal/aramid hybrid fabrics were produced and evaluated, considering both untreated sisal and sisal submitted to alkaline treatment with sodium hydroxide (NaOH) [5,6]. The laminates were tested under standalone target conditions using 7.62 mm ammunition. Impact and residual projectile velocities were recorded and used to calculate the absorbed energy and the equivalent velocity associated with absorbed energy (Veq). Macroscopic inspection and scanning electron microscopy were performed to assess damage morphology and failure mechanisms, including matrix cracking, delamination, fiber pull-out, sisal fiber rupture, and aramid fibrillation. NaOH treatment improved the sisal fiber–epoxy matrix interface and enhanced energy absorption, with the treated sisal composite showing the best ballistic performance. These results highlight the importance of interfacial control for improving natural fiber-based and hybrid composites for lightweight ballistic protection materials.

The construction industry faces the challenge of reducing its carbon footprint and the consumption of natural resources [1]. At the same time, the improper disposal of urban solid waste, such as soda-lime glass and polyethylene terephthalate (PET), represents a serious environmental issue. This research is aligned with the search for sustainable solutions, proposing the valorization of these wastes as constituent materials in cementitious matrices, aiming at the development of new construction materials with lower environmental impact. The main objective is to analyze the relationship between microstructure and mechanical performance of cementitious composites using partial replacement of Portland cement with recycled glass powder (RGP) and reinforcement with thermally treated PET fibers. In addition, the study seeks to determine the effect of combining these additions on matrix densification [2][3], compressive strength, toughness, and durability. As specific goals, the research evaluates the effects of RGP content (from 10% to 40%) [2][3] and PET fibers (0.5% to 1.5%) [3] on structural and mechanical properties, characterizes the microstructure using advanced techniques such as Scanning Electron Microscopy (SEM/EDS), X-ray Diffraction (XRD), and thermogravimetric analysis (TGA), and correlates these microstructures with material performance. The experimental methodology is divided into two main phases: first, the calibration of mortar matrices with a 1:3 mix ratio and a water/cement ratio of 0.40 [3][4], using materials such as CPII-Z-32 cement, thermally treated glass powder [5], and PET fibers [3][4]. Subsequently, concrete is produced using an adapted ABCP mix design method. The thermal treatments of the glass powder are varied, including temperatures of 450°C, 500°C, and 550°C, aiming to optimize its pozzolanic activity and reactivity, as well as to assess its effect on the matrix microstructure [5]. Preliminary conclusions indicate that replacing up to 20% of cement with RGP reduces porosity and enhances the formation of C–S–H gel, improving compressive strength, which reaches approximately 31.67 MPa at 28 days. The addition of PET fibers also demonstrates improvements in flexural strength and ductility of the composite, as well as contributing to crack control, with potential for low- to medium-complexity structural applications. The study shows that thermal treatment of glass powder increases its pozzolanic and densifying activity within the microstructure, in addition to improving the adhesion between matrix and fibers, thereby enhancing the mechanical performance of the material. Finally, the integration of these wastes with PET fibers aligns sustainability with technical performance, contributing to the advancement of more eco-friendly and resistant construction materials.

Polymer-derived ceramics (PDCs) are promising candidates for high-temperature structural applications due to their thermal stability, oxidation resistance, and compositional tunability from liquid preceramic precursors. However, conventional routes require prolonged high-temperature dwell times and cause undesirable compositional interactions and phase evolution. This study investigates the phase evolution of SMP-10-derived SiC and SMP-10/Ti₃C₂Tₓ MXene composites processed via ultrafast high-temperature pyrolysis, in which temperatures between 1100 and 2000 °C are reached within seconds using Joule-heated carbon felt under argon atmosphere.

X-ray diffraction, scanning electron microscopy, fractography, and thermogravimetric analysis reveal a temperature-dependent transformation sequence in the MXene-containing system. Ti₃C₂Tₓ flakes are encapsulated within the amorphous SiC matrix and retained up to 1300 °C, where they serve as heterogeneous nucleation sites that promote earlier β-SiC crystallization relative to the MXene-free system. At 1600 °C, the MXene undergoes topotactic conversion into TiC platelets that co-exist with SiC nanograins, with TiC platelets simultaneously acting as nucleation sites that increase SiC grain growth. At 2000 °C, a β-SiC/TiC composite with increased crystallinity is formed, accompanied by limited interdiffusion at the phase boundaries.

These results demonstrate that ultrafast heating kinetically suppresses MXene decomposition, enables novel MXene-to-TiC topotactic transformation, and provides a rapid processing route for multiphase PDC nanocomposites with implications for structural and high-temperature applications.