Materials and Technology

STUDY ON THE DYNAMIC COMPRESSION PROPERTIES OF A 0.5 % GRAPHENE/6061 ALUMINUM MATRIX COMPOSITE

Qinghui Song — 2025-09-30

Dynamic compression experiments were conducted on a 0.5 w/% graphene/6061 aluminum matrix composite using a split Hopkinson pressure bar (SHPB) at varying strain rates. The effects of these strain rates on the mechanical properties and deformation damage of the graphene/6061 aluminum matrix composite were analyzed. The results indicate that the composite exhibits significant strain rate sensitivity; specifically, the yield strength of the composite progressively increases with the rise in compressive strain rate, and high strain rate compression leads to notable grain refinement. Additionally, the finite element method was utilized to establish a corresponding numerical model to simulate impact compression at high strain rates. It was observed that the primary internal damage during the compression process is interface damage. When compared to the experimental results, the trends in mechanical changes are similar, and the error falls within a reasonable range, thereby validating the effectiveness of the finite element simulation.

INFLUENCE OF CR-FREE ANTI-FINGERPRINT PASSIVATION FILMS ON THE FRICTION RESISTANCE OF HOT-DIP Al-Zn COATED CARBON STEEL SHEETS

Degao Qiao — 2025-09-30

Currently, the absence of an effective scientific methodology for evaluating the friction resistance of Cr-free anti-fingerprint Al-Zn coated carbon steel sheets has significantly hindered the qualitative assessment and real-time monitoring of product quality by manufacturers and their downstream users. In this study, we systematically investigate the friction resistance of Al-Zn coated carbon steel sheets treated with three mainstream types of Cr-free anti-fingerprint passivation solutions: polymer-based (Granocoat 621), silane-based (DS981LX), and resin-based (PC-815) passivation solutions, utilizing a high-speed ring-block friction and wear tester. Our experimental results reveal that the friction coefficient curves exhibit a distinct three-stage pattern, corresponding to the sequential wear of the passivation film, the Al-Zn alloy layer, and the underlying carbon steel substrate. Notably, the initial significant increase in the friction coefficient is indicative of a failure of the passivation film due to wear. The friction durability of the Granocoat 621, DS981LX, and PC-815 passivation films was determined to be 287 s, 581 s and 684 s, respectively, with the water-based polyurethane resin-based passivation film (PC-815) demonstrating superior friction resistance. This enhanced performance is attributed to the strong chemical bonding between the water-based polyurethane and the Al-Zn alloy layer, as well as the synergistic effect of the silane coupling agent. These findings provide both theoretical and experimental foundations for establishing a scientifically validated method for evaluating the friction resistance of Cr-free anti-fingerprint Al-Zn coated carbon steel sheets, offering crucial insights for manufacturers aiming to improve the friction resistance of their products.

STUDY ON TIG ADDITIVE MANUFACTURING OF 4043 ALUMINIUM ALLOY

Lixing Qiu — 2025-09-30

4043 aluminum alloy components were successfully fabricated in this study using TIG (tungsten inert gas) additive manufacturing with an ER4043 filler wire. The microstructure and mechanical properties of the as-deposited material were systematically investigated. Results demonstrated that the TIG-deposited components exhibited favorable geometric integrity. Metallographic observations revealed a microstructure dominated by coarse dendritic grains, which grew continuously across interlayer regions. Tensile tests indicated minimal anisotropy in strength: the average tensile strength parallel and perpendicular to the welding direction was 146.1 MPa and 148.7 MPa, respectively. However, the elongation parallel to the welding direction (23.91 %) was notably higher than that perpendicular to it (19.31 %). The observed elongation (19–24 %) surpasses conventional cast 4043 alloys (10–15 %), likely due to the absence of large-scale casting defects (e.g., shrinkage cavities). This highlights the potential of TIG AM as a hybrid manufacturing method for aluminum components requiring balanced strength and ductility.

SYNTHESIS OF MORPHOLOGY-CONTROLLED ZnO NANOSTRUCTURES AND EVALUATION OF THEIR PHOTOCATALYTIC AND GAS-SENSING PROPERTIES

Shu Cui — 2025-09-30

ZnO samples with two distinct morphologies (porous particles and grenade-like structures) were synthesized via a sol-gel-hydrothermal method in a water-ethylene glycol binary solvent. By tuning the zinc precursor concentration, the morphologies were precisely controlled. In the investigation of photocatalytic properties, we evaluated the material’s ability to degrade the organic dye Rhodamine B (RB) under UV light. Additionally, we analyzed the active radicals generated during photocatalysis and evaluated the material’s recyclability. In the study of gas-sensing properties, we conducted a series of performance tests under various conditions, including temperature, gas concentration, cycle stability, response and recovery times, and comparative responses in different atmospheres. Our results showed that the samples exhibited superior ethanol selectivity. Moreover, all samples exhibited excellent cycle stability and fast response times. The small size and porous structure of the samples significantly enhanced their gas-sensing performance by providing ample channels and space for gas diffusion and reaction during testing. This unique morphology significantly improved the material’s gas-sensing performance.

NANOSILICA AS AN AUXILIARY ADDITIVE IN BEHAVIOUR ENHANCEMENT OF WEAK SOIL SUBGRADE

Pavithra Sakthi Vinayagam — 2025-09-30

Nanosilica has enormous potential for applications in pavement engineering. The present study evaluated the contribution of nanosilica as a secondary additive towards enhancement of the compressive strength of soil for its application in the construction of roads and embankments with lime as the primary additive. Considering both short-term and long-term curing, unconfined compressive strength tests were performed on soil modified with lime and the soil-lime mixture with the optimal proportion of nanosilica for curing periods of (0, 7, 14, 28, 90 and 120) days. Though lime-modified soil had good strength characteristics, the present study revealed an elevated compressive strength with the addition of the optimum dosage of nanosilica (0.75 % by mass of soil) in a short-time span. Strength improvement of 11.05 times and 17.57 times that of the virgin soil were achieved in the case of lime-modified soil without and with nanosilica, respectively. Durability tests were conducted to evaluate the effective contribution of nanosilica to the strength retention of soil subgrade subjected to wetting-drying and freeze-thaw cycles. The increase in the California bearing ratio (CBR) of the lime-modified soil without and with nanosilica by 4.23 times and 5.36 times that of the virgin soil demonstrated the efficacy of nanosilica in the reduction of pavement thickness. The study thus provided an improved assessment of the use of nanosilica for strengthening weak soil subgrade.

ENHANCED SURFACE ENGINEERING OF ENB ALLOY COATINGS: TRIBO-MECHANICAL INSIGHTS INTO HEAT TREATMENT AND SODIUM BOROHYDRIDE LEVELS

D. R. P. Rajarathnam — 2025-09-30

The optimization of coating parameters was the main focus of earlier research on electroless Ni-B (ENB) coatings; nevertheless, little is known about how bath composition and heat treatment temperature affect nanoindentation characteristics such scratch hardness, elastic modulus, and nanohardness. EN8 steel specimens with different concentrations of sodium borohydride (NaBH₄) are coated with ENB and heated at (355, 455 and 555) °C in order to examine these aspects. The results show that a higher boron content and larger nodules, raising the concentration of NaBH₄, improve nanohardness and elastic modulus. Due to the production of boride phases, which contribute to a more compact shape, these qualities are further enhanced with heat treatment. Additionally, scratch hardness rises with the concentration of NaBH₄, peaking at 455 °C, where the hard Ni₂B phase is most noticeable. Due to their homogenous and compact structure, the coatings show better resistance to wear and friction, even when their surface roughness decreases after being heated.

ENHANCING THE DURABILITY AND MECHANICAL PERFORMANCE OF BAMBOO FIBER-REINFORCED CONCRETE THROUGH MAGNESIUM HYDROXIDE MODIFICATION UNDER WET-DRY CYCLES

Yiming Jiang — 2025-10-01

This study systematically investigates the effects of different treatment methods (untreated and magnesium hydroxide [Mg(OH)₂] treated fibers) and varying fiber dosages (0, 1.2, 1.8, 2.3 and 2.8) % on the mechanical properties and durability of bamboo fiber-reinforced concrete (BFRC). Compressive, tensile, and flexural strength tests were conducted before and after 16 wet-dry cycles, and scanning electron microscopy (SEM) was used to analyze the microstructure of bamboo fibers and their interfacial bonding mechanisms, establishing the durability of BFRC. The results indicate that as the bamboo fiber content increases, the compressive strength of BFRC decreases, while the tensile and flexural strengths reach their optimal values at a 2.3 % fiber content. Untreated bamboo fibers contain surface impurities, leading to weak interfacial bonding with the cement matrix, whereas Mg(OH)₂-treated fibers exhibit a cleaner surface and significantly enhanced interfacial adhesion. After 16 wet-dry cycles, BFRC with untreated fibers showed a flexural strength loss of 11.5–12.7 %, compared to 17.4 % for plain concrete. BFRC with Mg(OH)₂-treated fibers further reduced the loss to 8.2–8.9 %, confirming the treatment’s effectiveness. This study provides new insights into the development of high-durability and sustainable bamboo fiber-reinforced composites and establishes a theoretical foundation for their application in civil engineering.

BEHAVIOUR OF HIGH-PERFORMANCE CONCRETE BEAMS WITH SILICA AND PINEAPPLE LEAF FIBER FOR ENHANCED STRUCTURAL BEHAVIOUR

Bebitta Robinson Chellathurai — 2025-10-01

This study explores the mechanical performance of high-performance concrete (HPC) beams incorporating silica fume (SF), and nano silica (NS) as cement replacements and pineapple leaf fibre (PALF) as a secondary reinforcement for enhancing the strength of the beams. The objective of this research is to examine the load-bearing capacity, deflection and failure mode of the beams. Various proportions of SF (5, 7.5, 10 and 12.5) % and NS (0.5, 1, 1.5, 2 and 2.5) % were incorporated into the concrete mix, with a constant addition of 2.5 % PALF. The beams were cast, cured for 28 days, and subjected to static loading tests, employing single-point loading methods to assess their load-carrying capacities and flexural behaviour. Experimental results demonstrated that beams with 10 % SF and 2 % NS exhibited superior structural performance, achieving the highest load-carrying capacity among all tested mixes. Crack patterns indicated flexural failure in all specimens, affirming their ductile behaviour under loading conditions. This investigation highlights the synergistic effects of SF, NS, and PALF in enhancing the strength and ductility of HPC beams, offering promising insights for advanced construction applications.

TEMPERATURE PERFORMANCE AND RUTTING PREDICTION OF STEEL SLAG ASPHALT MIXTURES

Hongwen Du — 2025-10-01

Steel slag, an industrial by-product, can replace basalt aggregate in road construction, helping to reduce the extraction of natural resources. By combining steel slag with waste rubber powder to produce steel slag–rubber-modified asphalt mixtures, both the material performance is enhanced and resource recycling is promoted. However, due to slight differences in high-temperature behavior between steel slag–rubber-modified asphalt mixtures and traditional basalt-based mixtures, existing rutting prediction models fail to accurately characterize the rutting development of the modified materials. To address this, four different types of asphalt mixtures were prepared in this study: full steel slag–rubber-modified warm-mix asphalt (CR-WSAM), partial steel slag–rubber-modified warm-mix asphalt (CR-WSBAM), full steel slag–rubber-modified hot-mix asphalt (CR-HSAM), and partial steel slag–rubber-modified hot-mix asphalt (CR-HSBAM). Uniaxial compression, Hamburg wheel tracking, and dynamic modulus tests were conducted, and a new rutting prediction model was developed by incorporating key factors influencing the rut formation. The results show that the proposed model outperforms existing models in terms of both accuracy and applicability, providing a more precise description of the rutting behavior of steel slag–rubber-modified asphalt mixtures. Furthermore, the model’s predictions show a higher correlation with measured rut depth values, indicating improved prediction accuracy.

INFLUENCE OF PLASMA NITRIDING PARAMETERS ON THE MECHANICAL PROPERTIES OF 25Cr2Ni4W STEEL

Brahim Chermime — 2025-10-01

In this study, plasma nitriding was applied to 25Cr2Ni4W low-alloy steel to improve its mechanical and tribological surface properties. The investigation focused on varying the negative bias voltage while keeping the discharge power, pressure, and holding time constant. The substrate temperature increased due to the self-induced heating mechanism. The compound layer of the treated samples revealed the formation of nitride phases (ε-Fe_2-3N and γ'-Fe₄N), as observed through XRD analysis and optical microscopy. A phase transition was noted between 2.0 kV and 3.5 kV, accompanied by an increase in the volume fraction of the γ '-Fe₄N phase and a decrease in the volume fraction of the ε -Fe_2-3N phase. When comparing the nitrogen-implanted samples to their untreated counterparts, an increase in nanohardness was observed, suggesting that the nitride phases contributed to the hardening.

THE EFFECT OF Y ON THE PERFORMANCE AND MICROSTRUCTURE OF FeCoCrNiMnTi0.6 HIGH-ENTROPY ALLOY COATINGS

Shenhao Wang — 2025-10-01

In this study we prepared FeCoNiCrMnTi_0.6Y_Xwt% (x=0.5, 0.75, 1, 1.25) high-entropy alloy coatings on c45 steel substrates using the laser-cladding method. The microstructure and properties of the cladding layers were investigated. The results indicated that the cladding layers exhibited good metallurgical bonding with the substrate, with the coatings comprising an FCC phase matrix accompanied by the precipitation of the Laves phase. With the addition of Y, the grain size of the coatings was gradually refined. Owing to the combined effects of grain-refinement strengthening, second-phase-precipitation strengthening, and solid-solution strengthening, the microhardness of the coatings increased, reaching up to twice that of the substrate. As the grains were refined, the wear resistance of the coatings initially increased and then decreased, with the optimal performance observed at x=1. The coatings also exhibited excellent corrosion resistance, which improved with increasing Y content.

STUDY ON THE EFFECT OF SINTERING TEMPERATURE ON THE PROPERTIES OF POROUS MATERIALS FROM WASTE GLASS

Do Quang Minh — 2025-10-01

The increasing volume of waste glass released into the environment underscores the critical role of material recycling, particularly glass recycling, in promoting sustainable development. A promising approach is the recycling of waste glass into porous materials. This study investigates the influence of sintering temperature on the properties of porous materials made from waste glass. The material samples were fabricated by adding liquid sodium silicate to glass powder at a glass powder/liquid sodium silicate ratio of 9/1. The optimal sintering temperature range for the porous material was determined through a heating microscope, revealing a suitable range of 770 ^oC to 830 ^oC. The sintered porous glass samples were determined by properties such as pore size distribution analysis, density, water absorption, and porosity measurements to evaluate the properties of the resulting product. Furthermore, the Fourier Transform Infrared Spectroscopy technique was employed to assess the functional group composition of the product. This research contributes to the search for effective waste glass recycling solutions while simultaneously producing porous materials with high application potential.

RESYNTHESIS AND ELECTROCHEMICAL PERFORMANCE OF NCM111 USING ULTRASOUND-ASSISTED LEACHATE FROM SPENT LITHIUM-ION BATTERY CATHODES

Honghao Yu — 2025-10-01

The widespread use of lithium-ion batteries (LIBs) led to a substantial accumulation of spent cathode materials, creating an urgent need for environmentally sustainable recycling methods that address both ecological concerns and the recovery of critical metals. A novel strategy integrating ultrasound-assisted deep eutectic solvent (DES) leaching and urea-assisted co-precipitation for the regeneration of high-performance LiNi₁/₃Co₁/₃Mn₁/₃O₂ (NCM111) cathodes from spent LiCoO₂ was developed. The results revealed that the transition metal-to-urea molar ratio critically governs the structural and electrochemical properties of regenerated materials. An NCM111 sample with an optimized transition metal-to-urea ratio of 1:2 had an ordered layered structure (I(003)/I(104) = 1.336), uniform spherical secondary particles (1–3 µm), and minimal cation mixing. These structural advantages translated into exceptional electrochemical performance, including an initial Coulombic efficiency of 84.84 %, 96.13 % capacity retention after 30 cycles, low charge-transfer resistance (37.26 Ω), and enhanced redox reversibility (ΔE_p = 0.21 V). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) further confirmed the superior interfacial kinetics and reaction reversibility of the optimised sample.

EFFECTS OF MANGANESE DIOXIDE AND SINTERING TEMPERATURE ON THE PROPERTIES AND MICROSTRUCTURE OF A SECONDARY-ALUMINUM-ASH CERAMIC PROPPANT

Yongming Zeng — 2025-10-01

In this study, a ceramic proppant for hydraulic fracturing in oil and gas extraction was prepared by sintering secondary aluminum ash as the main raw material, kaolin as the auxiliary material and manganese dioxide as the additive. The effects of different proportions of manganese dioxide on the physical phase composition and microscopic morphology of the proppant were analyzed with X-ray diffraction and scanning electron microscopy at sintering temperatures of 1170–1270 °C. The results showed that at 1270 °C, the crushing rate of the sample with a 2 w/% manganese dioxide addition was 8.41 %, and the main crystalline phase consisted of corundum and a small amount of mullite. With the addition of manganese dioxide, the ternary eutectic system of MnO₂-Al₂O₃-SiO₂ increases, which lowers the corundum generation temperature, accelerates its growth rate and improves the crushing resistance. This study solves the problem of weak crushing resistance of the ceramic-granule proppant prepared from secondary aluminum ash, and achieves an efficient use of waste, which is of great significance for environmental protection and resource recycling.

ACUTE EFFECT OF AURICULAR NERVE STIMULATION ON PERISTALSIS

Katarina Kalinić — 2025-10-01

This study aimed to assess short-term effects of transcutaneous auricular vagus nerve stimulation (taVNS) applied to four predefined sites on the cymba conchae (CC), with the goal of modulating specific physiological functions. A secondary objective was to investigate whether taVNS could influence bowel sounds (BSs), potentially indicating alterations in gastric motility. Five healthy female volunteers, aged 21 to 23 years, participated in the study. The taVNS procedure involved the insertion of a plug equipped with four globule-shaped platinum stimulating electrodes (cathodes) into the external ear. The common anode (CA) was positioned at the nape of the neck. Physiological measurements, including BSs and cardiac activity, were obtained using phonogastrogram (PGG) and forefinger photoplethysmographic (FPPG) recordings, respectively. The acquisition of the PGG signal was based on the detection of BSs during the taVNS application to the CC. The frequency and spectral characteristics of BSs were recorded using contact microphones (MICs). To evaluate the clinically relevant effects of taVNS on the gastrointestinal tract (GIT), volunteers were interviewed before and after the intervention, and their responses to a set of questions regarding GIT-related symptoms were analyzed. The results demonstrated an overall increase in normalized amplitude across all microphones, alongside an average increase in bowel sound frequency, except at MIC3. Notably, three out of five volunteers reported a sensation of hunger following the taVNS intervention.

PROGRAM AND BOOK OF ABSTRACTS 2025

Matjaž Godec — 2025-10-13

PROGRAM AND BOOK OF ABSTRACTS