Load-bearing Ability Research Articles

Nanodiamond-structured zinc composite coatings with strong bonding and high load-bearing capacity.

The aerospace and automotive industries find that relying solely on the intrinsic resistance of alloys is inadequate to safeguard aircraft and automotive structural components from harsh environmental conditions. While it is difficult to attribute accidents exclusively to coating failure due to the involvement of multiple factors, there are instances where defects in the coating initiate a wear or degradation process, leading to premature and unplanned structural failures. Metallic coatings have been introduced to protect the aircraft mainly from wear due to the extreme temperatures and moisture exposure during their service life. Bare metallic coatings have a limited lifespan and need to be replaced frequently. Herein, the strength and wear resistance of zinc (Zn) coating is enhanced using varying concentrations of diamond particles as an additive in the Zn matrix (Zn-D). The dispersion strengthening mechanism is attributed to the high hardness (70 HRC), and reduced friction-of-coefficient (0.21) and dissipation energy (4.6 × 10-4 J) of electrodeposited Zn-D7.5 (7.5 g l-1 of diamond concentration) composite coating. Moreover, enhanced wear resistance with minimum wear volume (1.12 × 10-3 mm3) and wear rate (1.25 × 10-3 mm3 N-1 m-1) of the Zn-D7.5 composite coating resulted in perfect blending of diamond with Zn. The improved hardness and wear resistance for Zn-D7.5 (optimum 7.5 g l-1 diamond concentration) is due to the steadiness between well-dispersed diamonds in Zn and enrichment in load-bearing ability due to the incorporation of diamond particles. Electronic structure calculations on the zinc-diamond composite models (two configurations adopted) have been performed using the density functional theory (DFT) approach, and the in silico studies appeared to facilitate meaningful and evocative outcomes. Zn-doped diamond (C10@Zn) without hydrogen (H) atoms (binding energy: 418 kcal mol-1, i.e. showing an endothermic reaction and thermodynamically not favourable) was detected to be more stable than the Zn-doped diamond (C10H16@Zn) consisting of hydrogen (H) atoms (binding energy: -33.3 kcal mol-1, i.e. showing an exothermic reaction and thermodynamically preferable). Thus, a composite coating of zinc and diamond can be a suitable candidate for the aerospace and automotive industries.

Research on Micro Gap Flow Field Characteristics of Cylindrical Gas Film Seals Based on Experimental and Numerical Simulation

Flexible support cylindrical gas film seals (CGFSs) adapt well to rotor whirling and have a good gas lubrication effect during thermal deformation. However, when a CGFS operates under the “three high” (high interface slip speed, high-pressure differential, and high ambient temperature) operating conditions, the complex deformation of the support structure is a crucial factor affecting the stability of the CGFS. A thorough and systematic analysis of the micro gap flow field characteristics of flexible support CGFSs is a fundamental problem when we study the deformation of the support structure under multiple physical field conditions. This study uses a cylindrical gas film high-speed rotor test rig to study and compare the sealing characteristics of experiments and numerical simulations and then optimizes and verifies the accuracy and effectiveness of the simulation model. A cross-scale gas film grid model is used to analyze the flow field characteristics and seal ability of different groove models and compare the mechanical characteristics and sealing performance. We also analyze the gas film pressure distribution in micro gaps and explore the impact of dynamic pressure groove microstructure on flow field characteristics. Results show that micro gaps are the primary conditions for generating hydrodynamic effects, and high rotational speed, high-pressure differential, and large eccentricity have a significant effect on improving hydrodynamic effects and enhancing gas film stability. However, an increase in these parameters can cause an increase in leakage rate. A single flow channel makes it easier to improve the hydrodynamic effect, gas film load-bearing ability, and gas film stability while reducing leakage rate. The analyses in this study supplement and improve the theory of the flow field characteristics of cylindrical annular micro gaps and provide a theoretical basis for exploring the relation between the support structural parameters of the CGFS and the mechanical characteristics of the micro gap flow field. This study provides important guidance to the establishment of a quantitative design theory of supporting structures.

Bamboo-Inspired Crack-Face Bridging Fiber Reinforced Composites Simultaneously Attain High Strength and Toughness.

Biological strong and tough materials have been providing original structural designs for developing bioinspired high-performance composites. However, new synergistic strengthening and toughening mechanisms from bioinspired structures remain yet to be explored and employed to upgrade current carbon material reinforced polymer composites, which are keystone to various modern industries. In this work, from bamboo, the featured cell face-bridging fibers, are abstracted and embedded in a cellular network structure, and develop an epoxy resin/carbon composite featuring biomimetic architecture through a fabrication approach integrating freeze casting, carbonization, and resin infusion with carbon fibers (CFs) and carbon nanotubes (CNTs). Results show that this bamboo-inspired crack-face bridging fiber reinforced composite simultaneously possesses a high strength (430.8MPa) and an impressive toughness (8.3MPam1/2 ), which surpass those of most resin-based nanocomposites reported in the literature. Experiments and multiscale simulation models reveal novel synergistic strengthening and toughening mechanisms arising from the 2D faces that bridge the CFs: sustaining and transferring loads to enhance the overall load-bearing ability and furthermore, incorporating CNTs pullout that resembles the intrinsic toughening at the molecular to nanoscale and strain delocalization, crack branching, and crack deflection as the extrinsic toughening at the microscale. These constitute a new effective and efficient strategy to develop simultaneously strong and tough composites through abstracting and implenting novel bioinspired structures, which contributes to addressing the long-standingly challenging attainment of both high strength and toughness for advanced structural materials.

The influence of microstructural characteristics and cell wall material properties on the mechanical behaviors of different tissues of sorghum stems

Sorghum stems comprise different tissue components, i.e., rind, pith, and vascular bundles in the rind and pith regions, of different cell morphologies and cell wall characteristics. The overall responses of stems to mechanical loadings depend on the responses of these tissues themselves. Investigating how each tissue deforms to various loading conditions will inform us of the failure mechanisms in sorghum stems when exposed to wind loadings, which can guide the development of lodging-resistant variants. To this end, numerical analyses were implemented to investigate the effects of cell morphologies and cell wall properties on the overall mechanical responses of the above four tissues under tension and compression. Microstructures of different tissues were constructed from microscopic images of the tissues using computer-aided design (CAD), which were then used for finite element (FE) analyses. Shell finite elements were used to model the cell walls, and the classical lamination model was used to determine the overall mechanical responses of cell walls having different fiber composite arrangements. The results from the numerical analyses helped explain how the loading (boundary) conditions, the cell microstructures, the mechanical properties of cell walls of different tissues, the cell wall thickness, the microfibril angle (MFA) of fiber composites of the cell walls, and the turgor pressure affected the overall mechanical responses of the tissues. Tissue stiffening or softening behaviors were attributed to different microstructural deformations, i.e., local or global buckling of cell walls, cell collapse, densifications of cells, or reorientation and rearrangement of cells. The mechanical properties and thickness of cell walls only affected the stiffness and load-bearing ability of the tissues. The turgor pressure affected the compressive responses but its effect on tensile responses was negligible. The MFA had a significant influence on the stiffness and load-bearing ability when the tissues were loaded along their longitudinal axis, but it had an insignificant effect on loading in the transverse direction. Tissues with smaller cell sizes and denser cells were stronger and stiffer than those with larger cell sizes. The numerical simulations also revealed that rind and rind vascular bundles were stiffer and had higher load-bearing ability than pith and pith vascular bundles.

Impact of Water Content on the Superlubricity of Ethylene Glycol Solutions

Aqueous solutions of water and ethylene glycol (EG) are prevalently employed in braking, heat transfer, and lubrication systems. However, the precise mechanism through which water content affects the lubricative attributes of EG solutions remains elusive. This research systematically examines the tribological characteristics of EG solutions at varying concentrations using a ceramic–TiAlN friction-pair system. As the concentration of EG increases, the sequential transformation of the associated molecular complex structure in the lubricating medium can be described as follows: [H2O]m·EG → [H2O]m·[EG]n → H2O·[EG]n. Among them, the stoichiometric coefficients “m” and “n” are the simplest mole ratio of H2O and EG in the molecular complex structure, respectively. The most favorable EG concentration was determined to be 50 wt.%. At this concentration, a flexible molecular complex adsorption structure ([H2O]m·[EG]n) with a significant bearing capacity (due to intense hydrogen bonding) forms on the surface of the friction pair, which results in a reduction in the running-in duration and facilitates the achievement of superlubricity, and the coefficient of friction (COF) is about 0.0047. Solutions containing 50 wt.% EG enhance the load-bearing ability and hydrophilicity of the lubricating medium. Moreover, they minimize the roughness of the worn region and curtail the adhesive forces and shear stress at the frictional interface, enabling the realization of superlubricity. Consequently, this research offers valuable insights into the optimal water-to-EG ratio, revealing the mechanism of a superlubricity system that possesses exceptional tribological attributes and holds significant potential for practical applications.

Hybrid hemp/glass fiber reinforced high-temperature shape memory photopolymer with mechanical and flame-retardant analysis

Cultivated natural fibers have a huge possibility for green and sustainable reinforcement for polymers, but their limited load-bearing ability and flammability prevent them from wide applications in composites. According to the beam theory, normal stress is the maximum at the outermost layers but zero at the mid-plane under bending (with (non)linear strain distribution). Shear stress is the maximum at the mid-plane but manageable for most polymers. Accordingly, a laminated composite made of hybrid fiber-reinforced shape memory photopolymer was developed, incorporating strong synthetic glass fibers over a weak core of natural hemp fibers. Even with a significant proportion of natural hemp fibers, the mechanical properties of the hybrid composites were close to those reinforced solely with glass fibers. The composites exhibited good shape memory properties, with at least 52% shape fixity ratio and 71% shape recovery ratio, and 24 MPa recovery stress. After 40 s burning, a hybrid composite still maintained 83.53% of its load carrying capacity. Therefore, in addition to largely maintaining the load carrying capacity through the hybrid reinforcement design, the use of shape memory photopolymer endowed a couple of new functionalities to the composites: the plastically deformed laminated composite beam can largely return to its original shape due to the shape memory effect of the polymer matrix, and the flame retardancy of the polymer matrix makes the flammable hemp fiber survive the fire hazard. The findings of this study present exciting prospects for utilizing low-strength and flammable natural fibers in multifunctional load-bearing composites that possess both flame retardancy and shape memory properties.

Axial compression behaviour of concrete filled double skin steel tube columns anchored with orbicular rings: Experimental and numerical approach

Double-skin tube column sections have been used extensively in recent years. These sections are composed of two adjacent, coaxially spaced steel casings, and the space in the middle of them is occupied with concrete. These CFDST columns behave similarly to CFST sections but are more rigid and have a lesser self-weight. The behavior of a novel type of CFDST column, the orbicular anchored CFDST column, was assessed under axial compression in the current research. It comprises an inside and an outside steel tube with orbicular rings near the ends of the columns. The orbicular rings were positioned at various spots such as [Formula: see text] and [Formula: see text] and a wide range of tests were accomplished to evaluate the functionality of orbicular anchored CFDST columns in respect of maximum load-bearing capability, load-strain behavior, and load-deformation behavior. A FE model was developed and its accuracy was authenticated by comparing its findings with experimental results. Furthermore, a parametric investigation was carried out employing the authenticated FE model to examine the functioning of the proposed CFDST to variations in orbicular position, cross-sectional dimensions of rings, yield strength of orbicular ring, etc. The outcomes of the study indicated that orbicular anchored CFDST columns had 15% higher ultimate load capacity than unstiffened counterparts. The orbicular anchorage improved the ductile response and increased the axial stiffness of the CFDST column. Further, it was concluded that orbicular rings enhanced the constraining effect of external steel casing on sandwiched concrete and improved the composite action of CFDST specimens. The design formula to ascertain the load-bearing ability of columns was also developed and can be employed amid preliminary designs of proposed column sections.

Comparative analysis of process-induced strain glass states in austenitic and martensitic NiTi shape memory alloy plates

Strain glass alloys (SGAs) are metallic alloys with glassy martensitic nanodomains within a crystalline material that occur from compositionally or processing-induced strain. SGAs originate from shape memory alloys (SMAs) and exhibit similar shape memory properties and high actuation densities. The transition from SMA to SGA is relatively unexplored, and although there are similarities to amorphous SMAs and cold-worked SMAs, SGAs should be distinguished as a separate grouping. The transition occurs by interrupting the long-range martensitic order, which in turn disrupts the martensitic transformation, resulting in short-range martensitic order. A glassy martensitic phase is produced that exhibits enhanced structural and load-bearing abilities, functional stresses, and recoverability. In this study, the transformation from SMA to SGA is explored in two common commercially available SMAs, Ni49.5Ti50.5 and Ni50.8Ti49.2 (at. %), to compare martensitic versus austenitic SGAs, respectively. SMA plates were cold worked in 5% increments until a strain glass transition occurred. Characterizations of the samples at various stages of cold work were examined via differential scanning calorimetry (DSC), Vickers hardness, transmission electron microscopy (TEM), and synchrotron radiation X-ray diffraction (SR-XRD). Some prominent characteristics between the two plates, such as enthalpy peaks, twin size reduction, and crystallographic structure, were examined and compared to improve the understanding of the SMA to SGA transition.

On the identification of the ultra-structural organization of elastic fibers and their effects on the integrity of annulus fibrosus

Due to the complicated structure of the elastic fiber network in annulus fibrosus, existing in-silico studies either simplified or just overlooked its distribution pattern. Nonetheless, experimental and simulation results have proven that elastic fibers are of great importance to maintaining the structural integrity of annulus fibrosus and therefore to ensuring the load-bearing ability of intervertebral discs. Such needs call for a fine model. This work aims at developing a biphasic annulus fibrosus model by incorporating the accurate distribution pattern of collagen and elastic fibers. Both the structural parameters and intrinsic mechanical parameters were successfully identified using single lamella and inter-lamella microscopy anatomy and micromechanical testing data. The proposed model was then used to implement finite element simulations on various anterior and posterolateral multi-lamellae annulus fibrosus specimens. In general, simulation results agree well with available experimental and simulation data. On this basis, the effects of elastic fibers on the integrity of annulus fibrosus were further investigated. It was found that elastic fibers significantly influence the free swelling, radial stretching and circumferential shear performances of annulus fibrosus. Nonetheless, no significant effects were found for the circumferential stretching capability. The proposed biphasic model considers for the first time the distribution characteristics of elastic fibers at two scales, including both the principal orientations of all fiber families and the detailed distribution pattern within each family. Better understandings on the functions of collagen and elastic fibers can therefore be realized. To further enhance its prediction capability, the current model can be extended in the future by taking the fiber–matrix interaction as well as progressive damages into consideration.

Resazurin-impregnated gelatin-based indicator for intelligent packaging applications

Modified resazurin (Res) incorporating gelatin (Gel) based indicator films were prepared to monitor the quality of packed shrimp in real time. FE-SEM micrographs show uniform dispersion of Res with minimal irregularities in the indicator film. The integration of Res increased the film's load-bearing ability and tensile strength without affecting the film's transparency and water vapor permeability. FT-IR and XPS profiles showed high compatibility and intermolecular H-bonds between the Res and Gel polymer matrices. The release rate of Res from the Gel-Res indicator film depended on the food simulant showing higher release rates in aqueous solutions (water and 10% ethanol) than in alcohol solutions (50% and 95% ethanol solutions). The Gel-Res indicator film exhibited excellent color stability even after storage for 60 days at room temperature. It was sensitive to ammonia vapor and alkaline pH solutions with a color change from yellow to pink with a total color difference (ΔE) of 15.4. In shrimp packaging tests, Gel-Res films exhibited noticeable color changes, which corresponded well with TVB-N levels and pH changes. These results suggest that the Gel-Res indicator films have acquired ideal prerequisites for potential intelligent seafood packaging.

The Study of the Failure Envelopes of Hollow Shaft Single-Plate Helical Piles in Clay

Helical piles are utilized worldwide as foundations for onshore infrastructure, providing fast installation and high capacity. Their unique advantages have led to their potential as an alternative to monopile foundations for offshore wind turbines. One challenge in their service life is dealing with combined loading caused by wind, waves, current, and the weight of the structure itself. While research has focused on helical piles’ capacity for uniaxial tensile loads, there is limited knowledge regarding their performance under combined loads. This study used FEM analysis to investigate the impact of aspects such as helix-to-shaft diameter ratios and helix position on the capacity and failure mechanisms of hollow shaft single-plate helical piles in clay. With 561 analysis cases under both uniaxial and combined loading, failure envelopes were evaluated for various helix-to-shaft diameter ratios and positions. The study revealed a linear positive correlation between helix-to-shaft diameter aspect ratios and load-bearing ability, while the effect of helix positioning on failure envelopes was more complex and nonlinear. The outcomes from this comprehensive analysis enabled the development of a formula to predict the bearing capacity of helical anchors under combined loading.

Stress-shielding resistant design of custom pelvic prostheses using lattice-based topology optimization

Endoprosthetic reconstruction of the pelvic bone using 3D-printed, custom-made implants has delivered early load-bearing ability and good functional outcomes in the short term to individuals with pelvic sarcoma. However, excessive stress-shielding and subsequent resorption of peri‑prosthetic bone can imperil the long-term stability of such implants. To evaluate the stress-shielding performance of pelvic prostheses, we developed a sequential modeling scheme using subject-specific finite element models of the pelvic bone-implant complex and personalized neuromusculoskeletal models for pre- and post-surgery walking. A new topology optimization approach is introduced for the stress-shielding resistant (SSR) design of custom pelvic prostheses, which uses 3D-printable porous lattice structures. The SSR optimization was applied to a typical pelvic prosthesis to reconstruct a type II+III bone resection. The stress-shielding performance of the optimized implant based on the SSR approach was compared against the conventional optimization. The volume of the peri‑prosthetic bone predicted to undergo resorption post-surgery decreased from 44 to 18%. This improvement in stress-shielding resistance was achieved without compromising the structural integrity of the prosthesis. The SSR design approach has the potential to improve the long-term stability of custom-made pelvic prostheses.

Enhancing the quasi-static strength of prosthetic socket made from composite laminates via hybridisation: Experimental and numerical study

This study aims to develop composite laminates for the manufacture of prosthesis socket with enhanced mechanical performance. Layered hybridisation of fabrics (i.e. glass, carbon, and Kevlar fabrics) is used to manufacture hybrid composite laminates by resin infusion via vacuum bagging method. The response of these materials to compression loading is investigated by using compression-loading testes and the load-bearing ability was examined by tensile strength tests. Moreover, finite element analysis has been carried out by using the Abaqus software to predict the compressive failure load and damage failure modes for all sockets samples. Experimental results revealed that the hybrid laminates exhibited more stability and higher absorbing energy compared to non-hybrid laminates during compressive loading tests. Furthermore, the hybridisation of fabrics layers can play key role for improving the tensile strength properties of hybrid composite laminates compared to composite laminates without hybridisation. The numerical simulation results of compressive failure load and damage failure modes are in accordance with experimental results qualitatively as well as quantitatively.

Breakthrough safety technology of explosion free in fire self-venting (TPRD-less) tanks: The concept and validation of the microleaks-no-burst technology for carbon-carbon and carbon-glass double-composite wall hydrogen storage systems

The paper describes the breakthrough microleaks-no-burst (μLNB) safety technology of explosion free in fire self-venting hydrogen tanks that do not require thermally-activate pressure relief devices (TPRD). The technology implies melting of the hydrogen-tight liner before hydrogen-leaky double-composite wall loses its load-bearing ability. Hydrogen then flows through the wall's microchannels and either burns in microflames on its own or together with resin. The experimental validation of the technology is presented for 7 prototypes with the nominal working pressure of 70 MPa made of carbon-carbon or carbon-glass composites. The prototypes are fire tested at the specific heat release rate HRR/A = 1 MW/m2 characteristic for gasoline/diesel spill fires. The μLNB technology eliminates catastrophic consequences of tank rupture in fire: blast waves, fireballs, and projectiles. The technology limits hydrogen accumulation in naturally ventilated enclosures. It reduces the risk of hydrogen-powered vehicles to an acceptable level below that for fossil fuel automobiles, including underground parking and tunnels. It provides an unprecedented level of life safety and property protection.

Large Deflection of Foam-Filled Triangular Tubes under Transverse Loading.

In this paper, the large deflection of the foam-filled triangular tube (FFTT) is studied analytically and numerically under transverse loading. Considering the strengths of the foam and the tube, the yield criterion of FFTT is established. Based on the yield criterion, a theoretical model for the large deflection of the clamped triangular tube filled with foam under transverse loading is developed. The numerical simulations are carried out using ABAQUS/Standard software, and the analytical results are compared with the numerical ones. The effects of foam strength, thickness of the tube, and the width of the punch on the load-bearing capacity and energy absorption of the clamped FFTT loaded transversally are discussed in detail. It is demonstrated that the load-bearing ability and the energy absorption increase with increasing foam strength, tube thickness, and punch width. The closer the loading position is to the clamped end, the greater the increases in the capacity of load bearing and the energy absorption of the triangular tube filled with foam. The theoretical model can be used to foresee the large deflection of metal FFTT under transverse loading.

Experimental study of manufacturing of human mandible using fusion deposit modeling (rapid prototyping)

Rapid prototyping method is used, for the manufacture of human mandible for replacement for accident victims. Rapid prototyping will make the manufacture of implants much easier and more exact than conventional methods such as titanium implant manufacturing in Alveolar ridge augmentation. After performing the necessary tests, the material selected for usage in the implants was ABS (Acrylonitrile Butadiene Styrene). Tensile tests are performed on ABS for implant manufacturing. Structured Light 3D Scanner is used to scan a life-size human mandible and the Standard Triangular Language (STL) file was created that file has been used in all the processes involved in the modeling and manufacturing of the Human Mandible by Rapid prototyping on ABS. FEM analysis is done on said material at different orientations using ANSYS 2021. From the test results it is found that the ABS material can sustain more than the required average bite force. Furthermore, a comparison of stress and load-bearing ability of bone and ABS is done to confirm the viability as a replacement material for bone in the mandible, which was found to be positive. The biocompatibility of ABS with the bloodstream and the body is researched and found to be positive. Implantation methods and bone powder coating variants are researched, to be able to fit the implant in the temporomandibular joint with the fastest recovery time.

Two-Way Shape Memory Effect of a Shape Memory Composite Strip

In this work, a NiTi shape memory alloy (SMA) wire was embedded into a rubber/shape memory polymer (SMP) soft matrix to form a composite strip with a two-way reversible bending behavior. First, the elastic moduli of SMA wire were characterized as increasing about 3 times (18.6 GPa at martensite phase and 50.1 GPa at austenite phase) from 25 °C to 90 °C. Then, an SMA composite strip using SMP to replace the rubber matrix was fabricated to significantly improve the load-bearing ability (16-fold) at 28 °C. After that, the good two-way bending behaviors of the rubber/SMP-based SMA strip with high shape deploying ratio above 80% were demonstrated. Finally, the application of rubber/SMP-based composite strips in a space-deployable antenna model with two-way reversible bending behavior was developed and demonstrated through a heating and cooling temperature cycle.

Rate capability and Ragone plots for thermal management multifunctional structure designing

With the miniaturization of electronic devices, thermal management has been widely concerned in aerospace engineering. A multifunctional structure with load-bearing and thermal management abilities is proposed and manufactured by combining shape-stabilized phase change material with carbon fiber reinforced plastic (CFRP). The Winkler foundation model is employed to study the load-bearing ability. And corresponding 3D failure mechanism maps are constructed for studying the dominant failure modes. The thermal rate capability and Ragone plots are used for investigating the thermal management ability under different thermal loads. Based on that, the physical properties of phase change materials and geometric parameters influences for thermal management ability are elucidated. Furthermore, the trade-off between load-bearing and thermal management abilities is illustrated by the specific strength – specific energy curves. The appropriate geometric parameters can be selected based on the practical applying conditions through thermal Ragone/structural strength plot. The proposed framework can provide reference for multifunctional structure design.

Controlling the mechanical failures of stir-cast Mg-AZ91D alloy using dicalcium silicate reinforcement

The poor load-bearing ability of Mg-AZ91D alloy leads to various mechanical failures like fracture, microcracks, ductile failure, and shear failure. To overcome the aforementioned failures, the present study introduces Ca2SiO4 as an effective reinforcement with the Mg-AZ91D matrix. The Mg-Ca2SiO4 composites were prepared with various weight percentages (2.5%, 5%, and 10%) using the conventional stir casting technique in an inert gas condition. The effect of different Ca2SiO4 /reinforcement particle weight percentages on the mechanical behaviour of Mg-Ca2SiO4 is studied. Various characterization tools like Scanning Electron microscope- Elemental mapping, Optical Microscope, X-ray diffractometer, Vickers hardness tester, Charpy impact tester, and Universal testing machine were employed. The morphology study confirmed the movement of Ca2SiO4 particles into an intergranular region of the Mg-AZ91D matrix, which played a vital role in the grain refinement of Mg-Ca2SiO4 composites. Mg-Ca2SiO4 composite produced a grain size of 84 µm, which is comparatively low than the Mg-AZ91D alloy. The Reinforcement of a higher weight percentage of Ca2SiO4 (10%) has improved the hardness (38.99%), tensile (45.54%), compression strength(31.68 %) and impact strength (31.99%) of Mg-Ca2SiO4 composite. The various strengthening and failure mechanisms associated with the Mg-AZ91D and Mg-Ca2SiO4 composites are further detailed in this study.

L-cysteine aided polyaniline capped SrO2 nanoceramics: Assessment of MC3T3-E1-arbitrated osteogenesis and anti-bactericidal efficacy on the polyurethane 2D nanofibrous substrate

Fabricating bioartificial bone graft ceramics retaining structural, mechanical, and bone induction properties akin to those of native stem-cell niches is a major challenge in the field of bone tissue engineering and regenerative medicine. Moreover, the developed materials are susceptible to microbial invasion leading to biomaterial-centered infections which might limit their clinical translation. Here, we successfully developed biomimetic porous scaffolds of polyurethane-reinforcedL-cysteine-anchored polyaniline capped strontium oxide nanoparticles to improve the scaffold’s biocompatibility, osteo-regeneration, mechanical, and antibacterial properties. The engineered nanocomposite substrate PU/L-Cyst-SrO2 @PANI (0.4 wt%) significantly promotes bone repair and regeneration by modulating osteolysis and osteogenesis. ALP activity, collagen-I, ARS staining, as well as biomineralization of MC3T3-E1 cells, were used to assess the biocompatibility and cytocompatibility of the developed scaffolds in vitro, confirming that the scaffold provided a favorable microenvironment with a prominent effect on cell growth, proliferation, and differentiation. Furthermore, osteogenic protein markers were studied using qRT-PCR with expression levels of runt-related transcription factor 2 (RUNX2), secreted phosphoprotein 1 (Spp-I), and collagen type I (Col-I). The overall results suggest that PU/L-Cyst-SrO2 @PANI (0.4 wt%) scaffolds showed superior interfacial biocompatibility, antibacterial properties, load-bearing ability, and osteoinductivity as compared to pristine PU. Thus, prepared bioactive nanocomposite scaffolds perform as a promising biomaterial substrate for bone tissue regeneration.