Characterization Of Mechanical Properties Research Articles

Ultra-high molecular weight polyethylene filled with iron by mechanical alloying

The ultra high molecular weight polyethylene (UHMWPE) shows properties that provide wide industrial and technological interest. To study the influence of iron particles on UHMWPE, the polymer was filled with Fe-powder in different stoichiometries through mechanical alloying (MA). The MA resultant samples were subjected to various analyses aiming at the characterization of mechanical, structural, and hyperfine properties. The tensile test indicated a small change in the stress-strain curves, this change was related to the yield stress. The X-ray diffraction showed the presence of a monoclinic phase, a metastable phase induced by deformation. Mössbauer spectroscopy pointed at the presence of three iron sites: metallic iron, Fe2+ e Fe3+. Considering these results, it is possible to ascertain that the iron weakly changes some properties of the polymer without degradation. There is a clear indication that iron atoms interact with carbon atoms, between the polymer chains, creating cross-links.

Characterization of microstructural evolution and mechanical properties of Cu-Ni-Cr alloys deformed by ECAP

In recent years, Cu-Ni-Cr alloy materials have been broadly applied in the marine industry. However, owing to its dendritic microstructure, this material is an obstacle to the manufacturing process, particularly in the metal-forming process. In this study, an equal-channel angular pressure (ECAP) process is proposed to improve the material microstructure and mechanical properties. A single pass of the ECAP was performed at room temperature, and the microstructural evolution and mechanical properties of the material were characterized. The ECAP compressed and tensioned the microstructures on the top and bottom surfaces, respectively. The microstructures on the front and back surfaces were similar because they were sheared. This also caused a tear-off of the dendritic microstructure. Based on the changes in the characterization of the microstructural evolution, the ultimate tensile strength increased by 32% to approximately 680 MPa, and the elongation decreased by 200% to approximately 8%. The microhardness distribution was irregular on the front and back surfaces, causing nonuniform deformation. However, the microhardness increased by an average of 35% to approximately 270 HV. Consequently, the nonuniform microstructural evolutions and mechanical properties of each surface must be considered when applying the ECAP process to improve the mechanical properties of Cu-Ni-Cr alloy materials.

Thermoplastic Starch with Maltodextrin: Preparation, Morphology, Rheology, and Mechanical Properties

This work describes the preparation of highly homogeneous thermoplastic starches (TPS’s) with the addition of 0, 5, or 10 wt.% of maltodextrin (MD) and 0 or 3 wt.% of TiO2 nanoparticles. The TPS preparation was based on a two-step preparation protocol, which consisted in solution casting (SC) followed by melt mixing (MM). Rheology measurements at the typical starch processing temperature (120 °C) demonstrated that maltodextrin acted as a lubricating agent, which decreased the viscosity of the system. Consequently, the in situ measurement during the MM confirmed that the torque moments and real processing temperatures of all TPS/MD systems decreased in comparison with the pure TPS. The detailed characterization of morphology, thermomechanical properties, and local mechanical properties revealed that the viscosity decrease was accompanied by a slight decrease in the system homogeneity. The changes in the real processing temperatures might be quite moderate (ca 2–3 °C), but maltodextrin is a cheap and easy-to-add modifier, and the milder processing conditions are advantageous for both technical applications (energy savings) and biomedical applications (beneficial for temperature-sensitive additives, such as antibiotics).

Preparation and Characterization of Mechanical Properties of HAP/45S5 Bioglass Laminated Ceramic Composites via Spark Plasma Sintering

Hydroxyapatite (HAP) displays a high degree of similarity to the inorganic components that make up roughly 70% of human hard tissue, and it possesses exceptional biological activity and biocompatibility. It is currently internationally recognized as the most biologically active hard tissue implant material. However, its substandard mechanical properties have significantly limited the application of HAP in areas requiring load bearing or in the repair of large bone defects. In this study, HAP/45S5 bioglass laminated ceramic composites were consolidated using the spark plasma sintering (SPS) technique. The grain growth and phase transformation of HAP and 45S5 bioglass were examined at various sintering temperatures. The mechanical properties of the laminated composites were investigated. At 950 °C, the flexural strength and fracture work of the sintered body were (153.22 ± 7.7) MPa and (2049 ± 34) J·m−2, respectively. These results corresponded to the load–displacement curves and showed that the composites met the mechanical performance requirements of the support material.

Update of the HTSI method: Application to the characterization of mechanical properties of CaF$$_2$$ from RT to $${800}\,^\circ \text{C}$$

Update of the HTSI method: Application to the characterization of mechanical properties of CaF$$_2$$ from RT to $${800}\,^\circ \text{C}$$

Photochemical Patterning and Characterization of Mechanical Properties on Soft Materials

AbstractAlthough different chemistries for the spatio‐temporal localization of molecules and gradients of chemical signals within soft materials are now available, the achievement of spatio‐temporal patterns of mechanical properties in such materials and their characterization remain considerable challenges. This study presents the syntheses of two novel photo‐sensitive and thermoresponsive hydrogel systems, a photo‐stiffening and a photo‐softening hydrogel. Their potential for fabricating soft materials with patterned mechanical properties is then demonstrated by fabricating an actuator whose higher‐order bending properties can be switched on with light, and by encoding mechanical properties for digital information encryption and storage. Microindentation and a custom‐made data analysis software are essential for the characterization of all the materials. From a general perspective, this work opens a route to the fabrication of soft materials with patterned mechanical properties, addressing an important emerging challenge in soft materials science with applications in soft robotics and information encryption and storage.

Prediction of single cell mechanical properties in microchannels based on deep learning

Traditional methods for measuring single-cell mechanical characteristics face several challenges, including lengthy measurement times, low throughput, and a requirement for advanced technical skills. To overcome these challenges, a novel machine learning (ML) approach is implemented based on the convolutional neural networks (CNNs), aiming at predicting cells’ elastic modulus and constitutive equations from their deformations while passing through micro-constriction channels. In the present study, the computational fluid dynamics technology is used to generate a dataset within the range of the cell elastic modulus, incorporating three widely-used constitutive models that characterize the cellular mechanical behavior, i.e., the Mooney-Rivlin (M-R), Neo-Hookean (N-H), and Kelvin-Voigt (K-V) models. Utilizing this dataset, a multi-input convolutional neural network (MI-CNN) algorithm is developed by incorporating cellular deformation data as well as the time and positional information. This approach accurately predicts the cell elastic modulus, with a coefficient of determination R2 of 0.999, a root mean square error of 0.218, and a mean absolute percentage error of 1.089%. The model consistently achieves high-precision predictions of the cellular elastic modulus with a maximum R2 of 0.99, even when the stochastic noise is added to the simulated data. One significant feature of the present model is that it has the ability to effectively classify the three types of constitutive equations we applied. The model accurately and reliably predicts single-cell mechanical properties, showcasing a robust ability to generalize. We demonstrate that incorporating deformation features at multiple time points can enhance the algorithm’s accuracy and generalization. This algorithm presents a possibility for high-throughput, highly automated, real-time, and precise characterization of single-cell mechanical properties.

Characterisation and prediction of mechanical properties in laser powder bed fusion-printed parts: a comparative analysis using machine learning

ABSTRACT This study investigates the effects of process parameters including scanning strategy, build orientation, and hatching distance on the mechanical properties of AlSi10Mg parts produced by Laser Powder Bed Fusion (L-PBF). The experiment varied these parameters within defined ranges and used statistical analysis to evaluate their impact on tensile strength and ductility. Results showed that scanning strategy had the greatest influence, followed by hatching distance, while build orientation affected anisotropic properties. Microstructural analysis showed clear correlation between process conditions and mechanical strength, thereby showing the underlying mechanisms that govern material behavior. Moreover, Machine learning models, including Random Forest Regression (RFR), Support Vector Regression (SVR), and Artificial Neural Networks (ANNs), were applied to predict tensile strength and ductility characteristics. RFR and SVR outperformed ANNs, showing high predictive accuracy with limited datasets. These findings emphasize the importance of optimizing L-PBF process parameters to minimize anisotropy and achieve consistent mechanical properties in produced parts.

Mode I cohesive law of birch wood-biobased adhesive systems

ABSTRACT The development and assessment of bio-based wood adhesives face challenges due to the limitations of conventional test procedures, particularly in predicting adhesive performance in real-world applications. This study investigated the mode I cohesive law of two birch wood-biobased adhesive systems, comparing them with conventional fossil-fuel-based systems. The experimental approach, developed during the ‘90s at Lund University, involves direct measurement of the traction-separation relation and allows evaluation of post-peak behaviour and fracture mechanical property characterisation. SEM analysis confirmed fracture development within the bond line for all tests. The birch–fish-adhesive bonds demonstrated peak stress of approx. 4 MPa, with serrated fracture surfaces and favourable fracture properties (specific fracture energy approx. 370 Nm/m2, brittleness approx. 40 GPa/m). Birch wood bonded with lignin-based adhesive showed lower, yet reasonable, levels of peak stress (approx. 3 MPa) but less favourable fracture properties (specific fracture energy approx. 110 Nm/m2, brittleness approx. 90 GPa/m), suggesting room for further optimisation.

Advances in Multiscale Modeling and Mechanical Properties Characterization of 3D‐Braided Composites

The 3D‐braided composites have been widely used in aerospace and other fields due to the excellent mechanical properties, designability, and resistance to delamination. Accurately analyzing and evaluating mechanical properties of braided composite structures is the key, which successfully designs related structural components. However, 3D‐braided composites have complex internal meso–microscopic structures, and directly establishing a solid structure model to predict mechanical behavior poses certain challenges. The multiscale research methods are a type of approach that studies the cross‐scale structural characteristics at macro–meso–microscopic scales and couples relevant scales into a whole. Its emergence provides the possibility for evaluating the overall structural performance of 3D‐braided composites. In this article, first, the multiscale analysis models of 3D‐multidirectional‐braided composites are reviewed, and then the theoretical and numerical research progress on the static and dynamic multiscale mechanical performance of regular components of 3D‐braided composites is summarized. In addition, due to the distortion and variation of geometric shapes of 3D‐braided composites on the meso–microscopic structure; therefore, also in this article, the research progress on multiscale mechanical performance characteristics of special‐shaped components is summarized. Finally, the key problems in the multiscale research of 3D‐braided composites are presented.

Characterization of Mechanical Properties and Surface Wettability of Epoxy Resin/Benzoxazine Composites in a Simulated Acid Rain Environment

Despite the robustness of thermosetting coatings in various applications, prolonged exposure to acidic environments can cause gradual deterioration, leading to structural or functional damage. This study investigates composite materials comprised of cycloaliphatic epoxy resin (CER) and benzoxazine (BZ) at three different weight ratios: 50:50, 25:75, and 0:100. These composites were exposed to nitric acid, simulating acid rain, for durations ranging from 1 to 5 h. The specimens were characterized for weight change, mechanical properties (flexural strength and short beam strength), and surface properties (contact angle and contact angle hysteresis). Although minimal changes in the physical and mechanical properties of both homopolymer and copolymer composites were detected after short acid exposure (up to 5 h), surface wettability analysis via static contact angle and contact angle hysteresis revealed more pronounced deterioration. The static contact angle decreased by 24.96% and 28.32% for homopolymer BZ and copolymer BZ-CER composites, respectively. Contact angle hysteresis increased by 19.39% and 27.80% for 5 h acid-exposed homopolymer BZ and copolymer CER, respectively. This study underscores the utility of surface wettability analysis as a valuable tool for monitoring deterioration from acidic aging in polymers, particularly in BZ-CER systems used in structural and high-performance applications.

Enhancing the recyclability of ELV plastic bumpers: Characterization of molecular, morphological, rheological, mechanical properties and ageing degradation

While the automotive industry has traditionally prioritized metal recycling, the increasing use of plastics in vehicles underlines the need for sustainable management of these materials. Recycling rates of plastics from end-of-life vehicles (ELVs) in Europe are low, but recent EU legislation requires 25 % of the plastics in new vehicles to be recycled, forcing innovative designs and strategies to enhance the recovery and quality of recycled resins. This study focuses on post-consumer bumpers, a significant recoverable component of ELVs, by assessing their molecular, morphological, rheological, and mechanical properties to investigate their homogeneity and quality from various sources to assess their suitability for recycling. Since the aging of these materials, caused by thermo-oxidative and thermo-mechanical degradation processes, can compromise the quality of recycled bumpers, we propose a blend of recycled PP from different bumper cars with virgin resin, representing a realistic scenario where the post-consumer ELV bumpers are collected. Interestingly, this blend, which can replace up to 50 % of the virgin resin without additional compatibilizers or additives, mitigates the degradation effects. Furthermore, the study evaluates the degradation resistance of these blends through multiple extrusion cycles and accelerated weathering tests in a temperature-controlled UV chamber to ascertain the number of cycles the material can tolerate without significant quality degradation, and to determine its suitability for long-term applications. Our results not only support the feasibility of using recycled PP for automotive components but also contribute to meeting the EU's recycling targets. This research highlights the potential for significant advances in the circularity of automotive plastics, providing a sustainable pathway for integrating recycled materials into new vehicle production.

Melt-Processed Polybutylene-Succinate Biocomposites with Chitosan: Development and Characterization of Rheological, Thermal, Mechanical and Antimicrobial Properties.

The current research is devoted to the development and characterization of green antimicrobial polymer biocomposites for food packaging applications. The biocomposites were developed by melt compounding on the basis of two different succinate polymer matrices with varying chain stiffness-polybutylene succinate (PBS) or its copolymer with 20 mol.% of polybutylene adipate (PBSA). Fungi chitosan oligosaccharide (C98) and crustacean chitosan (C95) were used as antimicrobial additives. The rheological properties of the developed biocomposites were determined to clear out the most suitable temperature for melt processing. In addition, mechanical, thermal, barrier and antimicrobial properties of the developed biocomposites were determined. The results of the investigation revealed that PBSA composites with 7 wt% and 10 wt% of the C98 additive were more suitable for the development of green packaging films because of their higher ultimate elongation values, better damping properties as well as their superior anti-microbial behavior. However, due to the lower thermal stability of the C98 additive as well as PBSA, the melt processing temperatures of the composites desirably should not exceed 120 °C. Additionally, by considering decreased moisture vapor barrier properties, it is recommended to perform further modifications of the PBSA-C98 composites through an addition of a nanoclay additive due to its excellent barrier properties and thermal stability.

Local characterization of mechanical properties and deformation mechanisms of SPS graded strain-transformable Ti-Nb alloy

Compositional boundaries of activity regarding transformation-induced plasticity and mechanical twinning (TRIP/TWIP) in Ti-Nb alloying system is determined by a novel methodology using chemically graded samples prepared by Spark Plasma Sintering. Presented methods of characterization include nanoindentation and microindentation testing complemented by EBSD analyses. The link between composition, microstructure, deformation mechanisms and mechanical properties can be established. Applied to the Ti-Nb system for a proof of concept, both the identification of local mechanical properties with respect to composition, and the refinement of the compositional ranges within which the different deformation mechanisms occur can be obtained. The graded sample ranging from 14 at.% to 34 at.% Nb is studied. TRIP/TWIP activity is resolved by EBSD in range 17 to 24 at.% of Nb, which is significantly lower than the results from the literature. This difference is attributed to the presence of interstitial oxygen (2470 ± 60 weight ppm).

Mechanical Property Characterization of 3D-Printed Carbon Fiber Honeycomb Core Composite Sandwich Structures

Mechanical Property Characterization of 3D-Printed Carbon Fiber Honeycomb Core Composite Sandwich Structures

DYNAMIC LIGHT SCATTERING-BASED MICRORHEOLOGY OF THERMOSENSITIVE CHITOSAN HYDROGELS: PRELIMINARY STUDIES

This paper presents a preliminary characterisation of the local mechanical properties of thermosensitive chitosan systems using dynamic light scattering, an endeavour that has not yet been attempted. The tests included solutions of chitosan chloride with the addition of sodium glycerophosphate as well as those without a substance to support the gelation process. There was much better agreement between the data obtained from measurements on the microscopic and macroscopic scales for systems without the addition of glycerophosphate. In most cases, the addition of a pH-neutralising salt resulted in higher values of dynamic moduli than those obtained during microrheological measurements. Therefore, it seems to be possible to use dynamic light scattering to conduct microrheological studies of thermosensitive chitosan systems.

Characterization of Mechanical Properties of Ramie/SiO2 Hybrid Composite by Incorporation of Kenaf Fiber

This study examines the mechanical characteristics of a novel hybrid composite consisting of 25% ramie fiber, 15% kenaf fiber, and 2% titanium dioxide particles. Ramie fiber is known for its tensile rigidity and durability, while kenaf fiber is valued for its availability and biodegradability. Titanium dioxide particles are included to enhance the composite's mechanical properties. Mechanical tests—including tensile, bending, impact, and hardness—were conducted, revealing an average tensile strength of 66.14 MPa, a flexural strength of 86.46 MPa, an impact strength of 35.88 kJ/m², and a hardness of 181.8 HV. The significance of this study lies in its innovative combination of natural fibers with inorganic particles, addressing the demand for high-performing yet eco-friendly materials. The novelty of the composite is reflected in the strategic integration of ramie and kenaf fibers, which offer complementary mechanical properties, with titanium dioxide particles to enhance overall performance. This approach achieves a balance between strength, rigidity, and impact resistance while maintaining environmental sustainability. The inclusion of titanium dioxide boosts mechanical performance without compromising the material's eco-friendly nature. These findings suggest that this composite is suitable for technical applications requiring exceptional strength, rigidity, and impact resistance. This research contributes to the advancement of composite materials technology, showing potential for the development of sustainable and effective materials across various industries.

Characterization of Mechanical and Viscoelastic Properties of Glass Fibre Reinforced Polymer Composites

Characterization of Mechanical and Viscoelastic Properties of Glass Fibre Reinforced Polymer Composites

Characterization of mechanical properties of shale constituent minerals using phase‐identified nanoindentation

Characterization of mechanical properties of shale constituent minerals using phase‐identified nanoindentation

Design and characterization of structural, mechanical, electronic, and optical properties of CrxMo1-xS2 alloys for advanced material applications

Design and characterization of structural, mechanical, electronic, and optical properties of CrxMo1-xS2 alloys for advanced material applications