Property Testing Research Articles

The Mechanisms of Nano‐AlN Content in the Microstructure and Mechanical Properties of Fe–25Mn–9Al–8Ni–1C–0.2Ti Alloy

In order to design a high‐strength, tough alloy for structural components, Fe–25Mn–9Al–8Ni–1C–0.2Ti–xAlN (x = 0, 0.25, 0.5, 0.75, and 1 wt%) alloys are prepared by powder metallurgy combined with vacuum arc melting. It can be seen from microstructure that the AlN/Al preform obtained by homogenizing mixing followed by vacuum pressureless sintering is added to the arc melting in the form of raw materials, and the AlN phase can exist stably and be uniformly distributed in the matrix. The main phases of the alloys are composed of austenite, ferrite, and TiC. With the increase of AlN content, the ferrite content is decreased and the grains are refined. The distribution of ferrite grains is changed from network to needle‐like and dot‐like morphology. Mechanical property test results reveal that the addition of the nano‐AlN can maintain the stability of the tensile strength while significantly improving its elongation after fracture. Specifically, when the AlN content is 0.5 wt%, the elongation after fracture reaches the maximum value of ≈55.8%, representing ≈98.5% improvement compared to the matrix alloy. It is attributed to the promotion of slip line formation by nano‐AlN, resulting in a higher density of slip lines within the alloy.

Study on the Hydrogen Evolution Reaction of Reinforced Concrete during Electrochemical Repair under the Influence of BIEM.

Based on the bidirectional electromigration (BIEM) technique, a corrosion inhibitor solution was prepared by mixing 1 mol/L triethylene tetramine with deionized water. The effects of current density, charging time, and corrosion inhibitor on critical current density and hydrogen content of rebar were investigated. Subsequently, the hydrogen embrittlement risk of rebar was further characterized by mechanical property tests. Finally, the bearing capacity and crack distribution characteristics of the components during electrochemical repair were revealed based on the microstructure of the steel fracture. Studies have shown that the corrosion inhibitor in the BIEM electrolyte reduces the polarization potential, increases the critical current density, and finally inhibits the hydrogen evolution rate. The hydrogen evolution reaction increases with the increase of current density and energizing time. The critical hydrogen evolution current density of concrete specimens measured ranges from 0.796 to 0.833 A/m2. In addition, the current density range of 1-7 A/m2 has no effect on the yield strength, yield platform, and ultimate strength of steel. With the increase of 1 μg/g hydrogen content, the fracture energy ratio of steel bars decreases by 12.18%, and the sensitivity coefficient of hydrogen brittleness increases by 9.92%.

Reasons for good high-temperature tensile rupture property of high-W content (Nb,W) co-alloying TiAl-based alloy under low stress

In order to explore why the high-W content TiAl-based alloy under low stress has better tensile rupture property, we still choose the vacuum-consumable-melted Ti-44Al-4Nb-1W-0.1B alloy. We carried out tensile rupture property testing at different time periods and different temperatures. The W content in (α2+γ) lamella matrix and microstructure before and after tensile rupture property testing are studied. At 800 °C, the B2 phase content gradually decreases and the W content in (α2+γ) lamella matrix gradually increases with the extension of time periods. For example, at 800 °C for 1370h, the B2 phase content has decreased from initial 12.024% to 1.188%. And, W content in matrix has increased from initial 0.88at.% to 1.07at.%. The tensile stress accelerates the radial diffusion of W atom. Importantly, EBSD analysis shows that, under low stress, there is no obvious stress concentration in the B2 phase region (≤800 °C), which avoids premature fracture, and makes B2 phase playing a good role in coordinating stress and strain, thus improving the tensile rupture property. However, at 900 °C, there is a slight stress concentration in the microstructure, leading to the formation of many holes, which is harmful to the tensile rupture property.

Corrigendum to “Size effect of typical hygrothermal properties test values for building insulation materials” [Energy Build. 325 (2024) 115049

Corrigendum to “Size effect of typical hygrothermal properties test values for building insulation materials” [Energy Build. 325 (2024) 115049

Kinetics analysis of radical photopolymerizations for UV-curable nanocomposites based on cellulose nanocrystals: Promoting and enhancing mechanisms.

The interfacial interactions between the enhanced nanoscale components and the polymer matrix, as well as the photopolymerization behavior of the composite system, are of paramount importance to the quality and performance of photo-curable nanocomposites. Cellulose nanocrystals (CNCs), a novel class of green reinforcing materials, are anticipated to facilitate the development of high-performance applications of advanced functional materials. Herein, the promoting and enhancing effects of modified CNCs on photo-curable nanocomposites are studied. As confirmed by the FTIR spectra, the active radicals introduced on the surface of the modified CNCs promote a stronger interfacial chemical interaction between the CNCs and the photopolymer molecules. Infrared thermography is performed to reflect the thermal energy changes during the photocuring of nanocomposites for investigating the acting mechanism of the modified CNCs on the curing behavior. Notably, the nanoscale structure and enhancement effect of CNCs contribute to the effective promotion of the curing reaction of the polymer matrix molecules, and increase their crosslink density. The non-isothermal differential scanning calorimetry (DSC) test is employed to assess the thermal properties of photocured nanocomposites with varying contents of modified CNCs, in order to identify the optimal UV curing process. Kinetic analysis based on the Kissinger model indicates that CNCs not only facilitated the formation of polymer networks, but also played a role in optimizing the reaction paths and reducing the energy barriers of the reactions. The results demonstrated that the 0.75 wt% CNC nanocomposites exhibited the most favorable reactivity at 50 and 100 mW/cm2 UV intensities, which is consistent with the mechanical property test data. In terms of micro-mechanism, the active radicals on the surface enhance the ability of CNCs to chemically bind to the photopolymer. This is coupled with their significant interfacial effects, which facilitate the formation of strong interfacial binding. The aforementioned findings provide a solid foundation for the construction of high-performance photo-curable nanocomposites.

Potential applications of PLGA/PVA coaxial nanofibers with controlled release for guiding tissue regeneration

Abstract Biomedical scaffolds are increasingly used in bone repair due to their exceptional ability to support cell growth and proliferation. This study developed a multifunctional poly(lactic-co-glycolic acid) (PLGA)/polyvinyl alcohol (PVA)/metronidazole coaxial electrospun nanofiber membrane to overcome the limitations of current bone tissue self-repair mechanisms. Optimization of the coaxial electrospinning parameters significantly improved the membrane’s overall performance. Mechanical property testing revealed that the tensile strength increased from 4.304 ± 0.079 MPa to 6.915 ± 0.032 MPa as the shell layer feeding rate was increased. Drug release studies demonstrated a marked reduction in the initial burst release of metronidazole as the shell layer thickness increased. The release amount decreased from 86% to 34% by the third hour, and the release continued over the course of one week. Furthermore, the in vitro release model transitioned from first-order kinetics to Peppas-Sahlin kinetics. In vitro studies confirmed that the metronidazole-loaded coaxial fiber membrane exhibited excellent biocompatibility, antibacterial properties, and osteogenic potential. In conclusion, PLGA/PVA controlled-release nanofiber membranes loaded with antibacterial drugs offer great promise for bone tissue regeneration therapies.

Internal mechanical properties test and constitutive analysis of compression concrete specimens

Internal mechanical properties test and constitutive analysis of compression concrete specimens

An intelligent thymol/alizarin-loaded polycaprolactone/gelatin/zein nanofibrous film with pH-responsive and antibacterial properties for shrimp freshness monitoring and preservation.

Improper storage methods cause food resources to be wasted, and the development of multifunctional intelligent packaging can realize freshness monitoring and extend the shelf life. In this study, an intelligent alizarin/thymol-loaded polycaprolactone/gelatin/zein nanofibrous film was prepared and achieved the dual functions of pH-responsive and antibacterial properties. The film was fabricated using electrospun technology and characterized by SEM, FT-IR, WCA, TGA, DSC, and mechanical property tests, which had good antioxidant properties (81.40±0.74% free radical scavenging). The film could effectively inhibit the growth of Escherichia coli, Staphylococcus aureus, and Shewanella putrefaciens within 12h and exhibited light yellow-light purple-dark purple color change at pH2-12, with good color stability and color responsiveness to ammonia in the environment. In the shrimp application, shelf life was extended by 2days and freshness could be monitored by the color change. This scientific research opens up new possibilities for realizing multifunctional food packaging alternatives.

Preparation of glass-ceramics via co-sintering of coal fly ash and metastable slag

ABSTRACT Coal fly ash (CFA) was used as the main object of study to prepare ash microcrystalline glass by co-sintering with metastable slag (MS) using its strong crystallization ability and sintering activity at low and medium temperatures. The effects of different material ratios on the crystalline phase composition and properties of the microcrystalline glass were discussed using various physical and chemical analysis methods in combination with mechanical properties tests. The results show that the compressive strength, density, chemical resistance and sintering densities of ash microcrystalline glass gradually increase with the increase of sintering temperature and the proportion of metastable slag. The compressive strength of the prepared ash microcrystalline glass can meet the requirements of GB/T19766–2016 “Natural Marble Building Panel” (≥50 MPa) when the addition amount of fly ash is 10–40% and the sintering temperature is 850–1085°C; among them, the chemical corrosion resistance of the prepared product meets the industrial requirements when the addition amount of fly ash is 10–30% and the sintering temperature is 940°C (acid loss rate ≤ 96%, alkali loss rate ≤ 98%).

OPTIMIZATION OF HPMC IN SERUM GEL CONTAINING BUTTERFLY PEA FLOWER EXTRACT (CLITORIA TERNATEA L.) AS FACIAL MOISTURIZER AND IT’S PHYSICAL STABILITY

Skincare refers to a series of skin treatments (epidermis) and the middle layer of the skin (dermis) aimed at protecting and maintaining the body, and is categorized as a cosmetic product. One of the most commonly used cosmetic preparations is skincare serum, which helps maintain skin elasticity and hydration. A rising trend in the industry is the development of serums, and one potential plant to be used as a safe active ingredient in cosmetics is the butterfly pea flower (Clitoria ternatea L), which is rich in flavonoids with antioxidant activity. The objective of this study was to determine whether butterfly pea flower extract serum can be formulated into a facial serum with moisturizing properties and to evaluate the physical stability of the serum preparation. The method used is Laboratory experiments were performed. The butterfly pea flower extract was obtained through maceration with 70% ethanol and then formulated into facial serum using different concentrations of HPMC base at 3%, 4%, and 5%. The results of serum stability tests were obtained using physical stability methods. Physical property tests included organoleptic testing (lavender scent, deep blue color, slightly thick, or serum-like texture), with stable organoleptic properties observed during storage, without any changes ...

Transformations of diatomite components and changesin its technical properties caused by calcination at different temperatures – a case study of the Jawornik deposit, Poland

Diatomite rocks from the eastern part of the Polish outer Carpathians come in several varieties with different colour, compactness, amount of clay and sandy substance as well as the degree of silicification. One of them is dark grey blocky diatomite, present in the Jawornik deposit and characterised by average quality. During the tests, it was thermally calcined at temperatures from 300°C to 1,200°C in order to improve its functional properties. The results of observations regarding the changes that the rock and its components underwent under conditions of increasing temperature were presented. The results of thermal analysis, X-ray diffraction and tests of physical properties (i.e. density, water absorption and Vickers microhardness) of the rock were presented. Detailed observations of the rock’s mineral components were made using a scanning microscope. Their physical changes (e.g. cracks or signs of melting) and chemical transformations were described. It has been shown that during calcination, irreversible changes occur in the mineral composition and structure of diatomite. It was proven that for the discussed diatomite the optimal calcination temperature is 900°C, as it ensures the greatest increase in its open porosity by 11% and an almost threefold increase in its hardness. The chemical composition of diatomite also changes due to the combustion of the organic matter present in it and the resulting relative increase in the 1,200 content. Calcination improves the technological features of this variety of diatomite, making it similar to the best quality varieties found in this deposit.

Cross-Cultural Adaptation and Psychometric Properties Testing of the Persian Version of the Emergency Department Forensic Nursing Survey.

Forensic nursing is an evolving specialty focusing on healthcare when legal issues are involved. Valid tools are needed to assess emergency department (ED) nurses' performance of forensic nursing role behaviors and their corresponding perceptions. We aimed to translate and culturally adapt the original English version of the "Emergency Department Forensic Nursing Survey" (EDFNS) into Persian and evaluate its psychometric properties among ED nurses. This methodological study was conducted in 2022. The EDFNS was translated into Persian. Face and content validity, along with construct validity (exploratory/confirmatory factor analyses) and reliability (internal consistency/test-retest reliability), were assessed. The EDFNS-P (EDFNS-Persian) items were appropriate, clear, and relevant in face validity assessment. Content validity was satisfactory for all items (content validity ratio = 0.66/content validity index = 0.92). In total, 274 nurses completed the questionnaires. The EDFNS-P consisted of five factors, namely, identifying forensic cases, acting as a forensic nurse specialist, assisting with legal investigations, providing holistic supportive care, and protecting forensic evidence, explaining 56.49% of the total variance. Confirmatory factor analysis assessment showed a good model fit. The EDFNS-P demonstrated acceptable internal consistency and stability (α = 0.902/intraclass correlation coefficient = 0.938). The concept of forensic nursing role behaviors within Iranian EDs is multidimensional. The EDFNS-P is a 37-item reliable and valid scale. It can help identify areas requiring improvement, promote better collaboration among healthcare professionals, and increase recognition of the specialty. Future studies examining the factor structure in different contexts are suggested to validate the findings. Further research is needed to assess the Persian version of the EDFNS in countries where forensic nursing roles are increasingly emerging.

Studying the geotechnical stability of the earth’s surface during the formation of different backfill mass types in quarry cavities

The research focuses on studying the geotechnical stability of backfill mass in the mined-out spaces of inactive quarries for restoring the earth’s surface in the conditions of the Kryvyi Rih region, where large-scale complex iron ore mining is conducted. Based on the analysis, it has been determined that in the region, to fill inactive quarry cavities and failure zones, the traditional method of filling them with dump waste rock is used. Given that the city of Kryvyi Rih is a densely populated, highly indutrialised agglomeration, the restoration of additional land areas could bring significant benefits for the economic development of the region, but the rock mass is not able to provide reliable geomechanical stability of the earth’s surface. The transformation of the physical state of the backfill mass from a loose to a monolithic state is proposed. In order to select alternative backfill methods, the quantitative and qualitative structure of the accumulated wastes of the mining-metallurgical complex that can be used as backfill materials is analyzed. Taking into account the significant volumes of accumulated beneficiation tailings and their limited utilization, it is recommended to use them as part of cemented paste backfilling, which will lead to an improvement in the environmental situation. The research methodology consists of laboratory tests of physical-mechanical properties of dump hard rocks, analysis of the properties of paste backfilling, and numerical modeling of stability of various types of backfill masses. It has been found that the mixture of rocks of 0...100 mm in terms of bulk density and voidness is close to the minimum fraction of 0...5 mm, which does not require the need to select a certain fractional composition. A «stress-strain» curve of a 0...100 mm rock mixture with a logarithmic relationship, characterized by three stages of strain, has been plotted. The strain modulus value has been calculated. The similarity of the mechanical characteristics of the studied mixture to the full-scale characteristics of dump hard rocks is substantiated. The modeling results show that the maximum strains in the case of rock backfilling reach 780 mm, while the calculations of paste backfilling show a significant decrease in the subsidence value, reaching only 43 mm. The difference in the values of subsidence is due to a significant difference in physical-mechanical properties. Based on studying the hardening conditions of paste backfill mixtures and temperature dynamics in the region, a seasonal approach and the formation of a combined backfill mass are proposed to maintain the reclamation rate. The research findings are valuable for the development of the construction direction of reclamation in the Kryvyi Rih region and the rational use of restored land areas.

Influence of Operating Temperature on Crack Growth Characteristics and Fatigue Life Prediction of Carbon Black-Filled Hydrogenated Nitrile Butadiene Rubber.

Rubber is widely used in situations involving cyclic loads, and the influence of temperature on rubber properties is particularly pronounced under cyclic loading. In this study, mechanical property tests and crack propagation tests of carbon black-filled hydrogenated nitrile butadiene rubber were conducted at four different operating temperatures. Based on the results of the crack propagation tests, the temperature-dependent characteristics of the Paris-Erdogan parameters and strain energy density were clarified. The Paris-Erdogan parameters were successfully expressed as a function of temperature. The strain energy density, on the other hand, exhibited the property of being strongly influenced by factors of strain, loading frequency, and others, while the temperature dependence was weak. On this basis, the unified fatigue crack growth kinetic model was constructed at multiple temperatures. The model results can match the experimental data well, particularly at temperatures of 60 °C and 80 °C. Finally, the fatigue life prediction model at different temperatures was constructed by combining the fatigue life test results. The results indicate a correlation between crack propagation characteristics and fatigue life predictions across different operating temperatures, with the predictions agreeing well with the measured life. The models can be used to analyze early fracture behavior or fatigue life prediction of rubber at different operating temperatures and minimize the need for extensive product testing prior to the manufacture of rubber products.

Effect of annealing on the structure and properties formation of a copper alloy alloyed with palladium and silver

A copper alloy with small additions of palladium and silver (Cu–1.5Pd–3Ag (at. %))—which has potential applications as a corrosionresistant conductor of weak electrical signals—was studied using X-ray diffraction analysis, microhardness measurements, specific electrical resistivity, and tensile mechanical properties tests. Samples were examined in several initial states: quenched (from 700 °C) and deformed at room and cryogenic temperatures (with a 90 % reduction in cross-sectional area in both cases). To study the processes of structural reorganization and property evolution, the initial samples were annealed in the temperature range from 150 to 450 °C (in 50 °C increments), followed by cooling in water or air. The duration of the heat treatments ranged from 1 to 48 hours. It was established that annealing the Cu–1.5Pd–3Ag alloy at temperatures below 450 °C leads to the precipitation of silver-based phase particles in the Cu matrix. Annealing of the initially quenched alloy was found to slightly increase its specific electrical resistivity (ρ) from 3.55·10–8 to 3.8·10–8 Ohm·m (after 48 h at 250 °C). It was revealed that alloying copper with 1.5 at. % palladium and 3 at. % silver enhances the strength properties (the yield strength of the alloy reaches 500 MPa) and raises the recrystallization temperature, while the electrical conductivity of the alloy remains around 50 % IACS. The optimal combination of properties (strength, ductility, and electrical conductivity) is observed after annealing the pre-cryodeformed alloy at 250 °C for less than 18 h. Extending the annealing time causes overaging, resulting in softening. The results of this study can be applied in the development of a new high-strength material with reduced electrical resistivity.

Research on the low-temperature performance of basalt fiber- rubber powder modified asphalt mixtures under freeze-thaw in large temperature differences region

Accurately assessing the low-temperature performance of asphalt materials is important for asphalt pavements in cold regions with large temperature differences. This study investigates the effects of freeze-thaw cycles on the low-temperature performance of basalt fiber-rubber powder composite modified asphalt mixtures (BRMAM). The influence of basalt fibers content on the mechanical properties of asphalt binder was characterized through basic property tests and bending beam rheometer (BBR) assessments. A freeze-thaw cycle process was designed to stimulate the more realistic climate. The deterioration of low-temperature performance and freeze-thaw damage mechanism were analyzed by the splitting tensile test, three-point bending test and semi-circular bending (SCB) test. Methods suitable for evaluating BRMAM’s low-temperature performance were compared and explored. The results indicate that when fiber content was about 0.3%, the reinforcement effect of basalt fibers on asphalt material was more pronounced. As freeze-thaw cycles progress, the impact of frost heave force on the cracking resistance significantly increases, while the influence degree gradually decreases. Excess fibers reduced the interfacial bond between rubber powder modified asphalt and aggregate. When fiber content is between 0.2 and 0.4%, BRMAM demonstrates optimal low-temperature performance and the least sensitivity to freeze-thaw cycles. After 30 cycles, the TSR of BRMAM with 0.3% basalt fiber even reached 47.6%.

Tribological properties of typical woods under water lubrication compared with the Lignum vitae

Purpose This study aims to investigate the potential of wood as a water-lubricated bearing material, determine the factors influencing the water-lubricated properties of wood and identify suitable alternatives to Lignum vitae. Design/methodology/approach Three resource-abundant wood species, Platycladus orientalis, Cunninghamia lanceolata and Betula platyphylla, were selected, and their properties were compared with those of Lignum vitae. The influencing mechanism of the tribological properties of different woods under water lubrication was thoroughly analyzed, in conjunction with the characterization and testing of mechanical properties, micromorphology and chemical composition. Findings The findings reveal that the mechanical properties and inclusions of wood are the primary factors affecting its tribological properties, which are significantly influenced by the micromorphology and chemical composition. The friction experiment results demonstrate that Lignum vitae exhibits the best tribological properties among the four wood species. The tribological properties of Platycladus orientalis are comparable to those of Lignum vitae, being only 17.1% higher. However, it is noted that higher mechanical properties can exacerbate the wear of the grinding pair. Originality/value The originality of this study lies in the combination of friction experiments and wood performance tests to identify the factors contributing to the superior water lubrication performance of wood, thereby guiding the application and improvement of different wood types in water-lubricated bearings. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0284/

COMPOSITE MATERIAL BASED ON WASTE RUBBER-PROOFED FABRICS

The article considers a method for processing interstitial waste of rubber-proofed fabrics into a composite material by crushing waste and fastening the resulting crumbs with polymer binders. Formulations have been worked out, samples have been obtained, and tests of physical and mechanical properties have been carried out. It is shown that the change in the size of the crumb, its proportions with the binder affects the characteristics of the samples. The coefficient of variation in thickness ranged from 4 to 20 %, the loss of 0.1 mm of thickness during abrasion ranged from 1,6 to 4,8 thousand cycles, the coefficient of tangential resistance during friction with a metal bar is from 0.51 to 0.60. The obtained materials can be used for the production of anti-slip coatings and other products.

Flexural Behavior of BFRP Bar-Recycled Tire Steel Fiber-Reinforced Concrete Beams.

This research advocates for the use of basalt fiber-reinforced polymer (BFRP) bars and recycled tire steel fibers to reinforce concrete beams. Six concrete beams were constructed using different volume contents of recycled tire steel fibers (0, 0.5%, 1.0%, 1.5%) and BFRP reinforcement ratios (0.48%, 0.75%, 1.08%). Mechanical properties tests were conducted to investigate the flexural characteristics and failure modes of beams utilizing the non-contact full-field strain displacement measuring technology-digital image (3D-DIC) technology. The recycled tire steel fiber (RTSF) improves flexural performance, which contributes to inhibiting crack propagation, reducing flexural deformation, and improving the first cracking and ultimate loading capacities. Under the same reinforcement ratio, in comparison to ordinary BFRP beams, the cracking load of BFRP-RTSF beams increased by 17.73%, 23.76%, and 42.94%, respectively, and the ultimate bearing capacity increased by 4.03%, 5.85%, and 13.21%, respectively. In addition, a modified calculation model of bearing capacity considering RTSF tensile strength is proposed. The predicted values of BFRP-RTSF beams match well with the experimental values.

Quasi-Static Mechanical Biomimetics Evaluation of Car Crash Dummy Skin.

Accurate replication of soft tissue properties is essential for the development of car crash test dummy skin to ensure the precision of biomechanical injury data. However, the intricacy of multi-layer soft tissue poses challenges in standardizing the development and testing of dummy skin materials to emulate soft tissue properties. This study presents a comprehensive testing and analysis of the compressive mechanical properties of both single and multi-layered soft tissues and car crash dummy skin materials, aiming to enhance the biofidelity of dummy skin. We presented one-term Ogden hyperelastic models and generalized Maxwell viscoelastic models for single-layer and multi-layer soft tissues, as well as dummy skin materials. The comparative analysis results indicate that the existing dummy skin material fails to fully consider the strain-rate-dependent characteristic of soft tissue. Furthermore, dummy skin materials exhibited ~3 times shorter relaxation times and ~2-3 times lower stress decay rates compared to soft tissues, suggesting a less viscous nature. This study provides an accurate representation of the mechanics of soft tissue and dummy skin under quasi-static compressive loading. The findings are instrumental for the development of novel bionic skin materials or structures to more precisely replicate the biomechanical properties of soft tissues, thereby enhancing the accuracy and reliability of car crash test dummies.