Nanomechanical Properties Research Articles

Changes in the composition and mechanical properties of dentin in mouse models of diabetes

ObjectivesThis study employed mouse models of type 1 (T1D) and type 2 (T2D) diabetes to characterize the changes in tooth dentin composition and its mechanical properties. MethodsThirty-two mice were used in this study and divided into T1D, T2D and corresponding control groups. Mandibles were extracted 12 weeks after the onset of diabetes, and dentin from the first molars was evaluated in varying regions of the root. The composition was assessed using Raman Spectroscopy. Nanoindentation and Vickers indentation were employed to study the mechanical properties of the tissue. Statistical significance was evaluated by two-way analysis of variance with respect to the diabetic group and region of the tooth (p ≤ 0.05). ResultsIn the T2D model, the mineral-to-collagen ratio, hardness, and storage modulus of the intertubular dentin were significantly reduced compared to tissue from the controls, especially in the cervical regions of the tooth. The reduction in the mineral-to-collagen ratio was also observed in the T1D model, but changes in nanomechanical properties were not evident. However, the bulk hardness of the teeth in the T1D model was lower than in the littermate controls. Optical microscopy revealed significant wear of the tooth crowns in both models of diabetes, which appear to result from parafunctional activities. ConclusionThis study suggests that both type 1 and type 2 models of diabetes are associated with detrimental changes in dentin. Clinical significanceBetter understanding of how diabetes affects dentin and the contributing mechanisms will be key to improving treatments for people with diabetes.

Maturity characterization and formation mechanisms of nano-scale anisotropic pyrobitumen based on atomic force microscopy (AFM)

Highly evolved pyrobitumen is an important and realistic object for maturity characterization of ancient and deeply buried organic matter, but measurement of its reflectance is challenging due to its strong optical anisotropy and nano-scale relief. Here we conducted a case study in the Sinian (Ediacaran) Dengying Formation of the Sichuan Basin, China. High-resolution, three-dimensional, morphological imaging by atomic force microscopy (AFM), laser Raman (LRM) spectroscopy, and reflectance studies were conducted on the reservoir pyrobitumen. Our results show that Young’s modulus and adhesion, which are mechanical maturity parameter, provides effective characterization of maturity. The increase in Young’s modulus of pyrobitumen lags that of the vitrinite, given that pyrobitumen is formed by oil cracking and is more hydrogen-rich than vitrinite. A quantitative relationship between Young’s modulus, adhesion and reflectance in bright and dark areas of pyrobitumen was established, which can be used for maturity characterization. The changes in Young’s modulus of the pyrobitumen is related to the condensation of organic matter and directional arrangement of microcrystals. Young’s modulus of organic matter is a robust mechanical maturity index at high organic matter maturity (Ro > 2.0 %), but it is important to pay attention to the influence of anisotropy. Compared to Young’s modulus, adhesion is less affected by anisotropy. The nano-mechanics such as Young’s modulus and adhesion will be new maturity indicator in addition to conventional optical and spectroscopic method. The nano-mechanical properties of organic matter are expected to be applied to maturity indicators and macerals classification in the field of organic petrology in the further research.

Machine learning approaches for improving atomic force microscopy instrumentation and data analytics

Atomic force microscopy (AFM) is a part of the scanning probe microscopy family. It provides a platform for high-resolution topographical imaging, surface analysis as well as nanomechanical property mapping for stiff and soft samples (live cells, proteins, and other biomolecules). AFM is also crucial for measuring single-molecule interaction forces and important parameters of binding dynamics for receptor-ligand interactions or protein-protein interactions on live cells. However, performing AFM measurements and the associated data analytics are tedious, laborious experimental procedures requiring specific skill sets and continuous user supervision. Significant progress has been made recently in artificial intelligence (AI) and deep learning (DL), extending into microscopy. In this review, we summarize how researchers have implemented machine learning approaches so far to improve the performance of atomic force microscopy (AFM), make AFM data analytics faster, and make data measurement procedures high-throughput. We also shed some light on the different application areas of AFM that have significantly benefited from applications of machine learning frameworks and discuss the scope and future possibilities of these crucial approaches.

Effect of fly ash and nano Silica on the formation and evolution of Calcium Silicate Hydrate in Portland Cement during hydration process

Recently, the trend of replacing cement with mineral admixtures in concrete has witnessed increasing interest in the construction industry due to the reduction in embodied energy and CO2 emissions. However, the addition of these admixtures in Portland Cement (PC) affected the formation as well as the structure of the hydration product Calcium-Silicate-Hydrate (C-S-H), which is reflected in the mechanical and durability properties of cement concrete. In the present study, nano-silica (NS) and a mixture of fly ash (FA) and NS were replaced into PC (PC + 0.5 % NS, PC + 1 % NS, PC + 0.5 % NS + 20 % FA and PC + 1 % NS + 40 % FA) to systematically study the formation and structural evolution of hydration products, namely C-S-H, at atomic and micro-scales at the early stage of hydration (3 days) and a later stage of hydration (90 days). The formation and structure of C-S-H were analyzed to correlate the microstructure development by using XRD, Rietveld technique, FESEM, TEM, FTIR and nano-scale mechanical properties by employing the nanoindentation techniques. Atomic Pair Distribution Function (PDF) is used to understand the effect of admixtures on the C-S-H structure from atomic point of view. PDF shows the structural modification of C-S-H such as different polyhedral, separation of intralayer/interlayer, pair/bond length, coordination number of atoms corresponding to the addition of additives with hydration age. Also, porosity measurements show increasing or decreasing porosity during hydration with additives. It is observed that the contribution of low-density C-S-H (LD C-S-H) is greater than that of high-density C-S-H (HD C-S-H) in the beginning days, whereas HD C-S-H more than LD C-S-H in the latter days of hydration. The elastic modulus increased from 15.44 GPa to 19.82 GPa and the hardness decreased from 0.41 GPa to 0.35 GPa of LD C-S-H in early days, whereas elastic modulus decreased from 34.84 GPa to 29.33 GPa and the hardness increased from 0.75 GPa to 0.83 GPa of HD C-S-H in the latter stage due to addition of additives. However, both increased for LD C-S-H and HD C-S-H for each corresponding mixture during hydration. The present study reported the formation and microstructural modifications of C-S-H and the correlation with nano-mechanical properties due to addition of nano or micro-sized admixtures (nano silica and fly ash) in the cement system. This correlation helps to develop low-energy cement composites by tailoring cement systems with desired properties.

Crystal structure-mechanical property relationship in succinic acid and L- alanine probed by nanoindentation

Establishing structure–mechanical property relationships is crucial for understanding and engineering the performance of pharmaceutical molecular crystals. In this study, we employed nanoindentation, a powerful technique that can probe mechanical properties at the nanoscale, to investigate the hardness and elastic modulus of single crystals of succinic acid and L-alanine. Nanoindentation results reveal distinct mechanical behaviors between the two compounds, with L-alanine exhibiting significantly higher hardness and elastic modulus compared to succinic acid. These differences are attributed to the underlying variations in molecular crystal structures − the three-dimensional bonding network and high intermolecular interaction energies of L-alanine molecules leads to its stiffness compared to the layered and weakly bonded crystal structure of succinic acid. Furthermore, the anisotropic nature of succinic acid is reflected in the directional dependence of the mechanical responses where it has been found that the (111) plane is more resistant to indentation than (100). By directly correlating the nanomechanical properties obtained from nanoindentation with the detailed crystal structures, this study provides important insights into how differences in molecular arrangements can translate into different macroscopic mechanical performance. These findings have implications on the selection of molecular crystals for optimized drug manufacturability.

The effect of chemical short-range order on incipient plastic behavior in FCC structured high entropy alloys

Chemical short-range order (CSRO) was assumed as one of the most important structure feature of high entropy alloys and the influence of CSRO on mechanical properties is a fundamental issue yet to be fully understood. In this work, we performed extensively nanoindentation experiments on CoCrFeNiAlx alloys to study the effect of CSRO on the incipient nanomechanical properties. The statistical nature of strengths at the first pop-in event was analyzed to gain insight of deformation mechanisms. All samples examined here exhibit bimodal distribution which indicate non-unique dislocation nucleation mechanisms. The bimodal distributions can be decomposed into two Gaussian distributions and the activation volumes can be obtained in the range of 0.73–1.38b3. The peaks shift to higher stress level after the development of CSRO. The heterogeneous dislocation nucleation plays a dominant role at low indentation stress with the aid of pre-existing crystalline defects. The homogeneous dislocation nucleation mechanism prevails when indentation stress close to theoretical values. The transmission electron microscopy characterization indicates the presence of chemical ordering in the aged samples. Both the degree of chemical ordering and lattice distortion are much higher in the Al containing HEAs due to the distinctive difference of properties in Al and other transition element atoms.

Investigation of the impact of environmental conditions on the mechanical properties of thin-film copper wafers

Thin-film copper offers excellent film texture for multilevel interconnections in integrated circuit fabrication due to its superior resistance to electromigration and high electrical conductivity. To perform a chemical mechanical planarization process during semiconductor fabrication of copper, it is necessary to have a thorough understanding of the nanomechanical properties of thin-film copper. In this study, thin-film copper and reacted passivation layers on silicon substrate wafers are investigated for their nanomechanical properties under various environmental conditions. The results of this study indicate that thin-film copper passivation layers have different properties in deionized (DI) water and polishing slurry environments compared to thin-film copper exposed to ambient air. Interestingly, variations in temperature within wet environments do not significantly affect the properties of thin-film copper wafers; but changes in properties are largely driven by chemical processes. The insights gained from this study emphasize the significance of considering both the passivation layers and wet environments in semiconductor fabrication processes, which contributes to the advancement of copper-based interconnect materials and optimization of the chemical mechanical planarization process in semiconductor manufacturing.

Effect of zirconium addition on microstructural characteristics and nano-mechanical properties of P9 steel

Micro-alloying in steels has significant effects on microstructure and its properties. The main objective of the work is to understand the influence of zirconium (Zr) addition to P9 ferritic/martensitic (F/M) steel on phase stability, microstructure, and nanomechanical properties. The alloy compositions in this study were designed using thermodynamic calculations, based on which steels with Zr concentration in the range of 0.05–2 wt.% were synthesized using vacuum arc melting. The cast alloy was subjected to thermo-mechanical treatments followed by austenitization and tempering treatments. Zr concentration of the steel was found to influence the nature of secondary phases formed, which were quantified through detailed synchrotron X-ray diffraction (XRD) analysis and also characterised extensively using electron microscopy techniques. Detailed structural analysis of the Fe23Zr6 phase using aberration corrected transmission electron microscopy is reported for the first time. The nano-mechanical properties of the heat-treated steels were evaluated using instrumented indentation tests at room temperature with a sphero-conical indenter. A systematic variation in hardness and yield strength with Zr content of P9 steel was observed, which is correlated to the microstructural changes. The P9 F/M steel with optimum concentration of Zr, with better mechanical properties is proposed through this structure-property correlation study.

Integrating TiNx to Fe-based amorphous coating by reactive plasma spray for ameliorating multi-scale mechanical behavior and corrosion-abrasion resistance

Ocean engineering components are subjected to intense corrosion and abrasion. To address these challenges, the Fe-based amorphous composite coating was engineered for compatibility with these harsh conditions. The Fe-based amorphous composite coating, incorporating TiNx, demonstrated improved nanomechanical properties, offering enhanced resistance against external forces. The integration of TiNx acted as a structural backbone, limiting crack propagation within the amorphous matrix. Although the corrosion resistance of this composite coating was slightly reduced, it demonstrated improved durability subjected to hydraulic machinery corrosion abrasion working condition. Notably, under conditions of higher tribological pair speeds and increased sand concentrations, this composite coating exhibited significantly lower weight loss increase and reduced wear rates escalation compared to coatings made entirely from Fe-based amorphous material. Moreover, the composite coating exhibited diminished susceptibility to erosion damage, with reduced size and severity of erosion craters. These underlying mechanisms are thoroughly discussed in the paper.

Revealing chemistry-structure-function relationships in shark vertebrae across length scales

Shark cartilage presents a complex material composed of collagen, proteoglycans, and bioapatite. In the present study, we explored the link between microstructure, chemical composition, and biomechanical function of shark vertebral cartilage using Polarized Light Microscopy (PLM), Atomic Force Microscopy (AFM), Confocal Raman Microspectroscopy, and Nanoindentation. Our investigation focused on vertebrae from Blacktip and Shortfin Mako sharks. As typical representatives of the orders Carcharhiniformes and Lamniformes, these species differ in preferred habitat, ecological role, and swimming style. We observed structural variations in mineral organization and collagen fiber arrangement using PLM and AFM. In both sharks, the highly calcified corpus calcarea shows a ridged morphology, while a chain-like network is present in the less mineralized intermedialia. Raman spectromicroscopy demonstrates a relative increase of glucosaminocycans (GAGs) with respect to collagen and a decrease in mineral-rich zones, underlining the role of GAGs in modulating bioapatite mineralization. Region-specific testing confirmed that intravertebral variations in mineral content and arrangement result in distinct nanomechanical properties. Local Young's moduli from mineralized regions exceeded bulk values by a factor of 10. Overall, this work provides profound insights into a flexible yet strong biocomposite, which is crucial for the extraordinary speed of cartilaginous fish in the worlds’ oceans. Statement of significanceShark cartilage is a morphologically complex material composed of collagen, sulfated proteoglycans, and calcium phosphate minerals. This study explores the link between microstructure, chemical composition, and biological mechanical function of shark vertebral cartilage at the micro- and nanometer scale in typical Carcharhiniform and Lamniform shark species, which represent different vertebral mineralization morphologies, swimming styles and speeds. By studying the intricacies of shark vertebrae, we hope to lay the foundation for biomimetic composite materials that harness lamellar reinforcement and tailored stiffness gradients, capable of dynamic and localized adjustments during movement.

Powder metallurgical processing of novel Al0.5CoCrFeNiNb0.5-Si0.1 high entropy alloys: Phase evolution and nanomechanical properties

In this research, the high entropy alloy (HEA) of Al0.5CoCrFeNiNb0.5-Si0.1 was successfully synthesized through mechanical alloying utilizing a high-energy planetary ball mill. The synthesized HEA powder was subsequently pressed and sintered at 1400 °C with varying holding times. The phase evolution was investigated using X-Ray Diffraction (XRD) technique. Furthermore, the microstructural, morphological, and compositional characteristics of the powders were examined using Transmission Electron Microscopy (TEM) with Selected Area Electron Diffraction (SAED), as well as Scanning Electron Microscopy (SEM) in conjunction with Energy Dispersive Spectroscopy (EDS). The nano-mechanical properties of the HEA compact were evaluated through nanoindentation to determine nano-hardness and elastic modulus.The mechanical alloying process was conducted for a duration of 30 h, resulting in the formation of a single-phase BCC solid solution, as confirmed by XRD and SAED analyses. The study investigated the criteria for phase stability based on the minimum Gibbs free energy and Hume-Rothery rules, which were consistent with the observed microstructural characteristics. Furthermore, the sintering process resulted in porosity levels of 6.01 % and 4.71 %, with corresponding densities of 6.96 g/cm³ and 7.12 g/cm³ for holding times of 3 and 4 h, respectively. It was noted that extended holding times improved the mechanical properties, with the alloy achieving a maximum hardness of 546 HV, nano-hardness of 5.57 GPa, elastic modulus of 265.47 GPa, and yield stress of 1.89 GPa after a holding time of 4 h.

Calcium-rich seawater affects the mechanical properties of echinoderm skeleton

Shifts in the magnesium to calcium ratio of seawater in the geological history are thought to have profoundly affected biomineralization of marine invertebrates, including some echinoderms, which changed their skeletal mineralogy from high-magnesium to low-magnesium calcite and vice versa. Here we report on experiments that aimed to investigate the effect of ambient seawater magnesium to calcium ratio on magnesium to calcium ratio and nanomechanical properties in the spines of two echinoid species (Arbacia lixula and Paracentrotus lividus). We found that echinoids cultured in seawater with a low magnesium to calcium ratio produced a skeleton with lower both magnesium content and nanohardness than those of the control specimens incubated under normal (high) magnesium to calcium ratio conditions. These results may suggest that at certain times in the geological past (during the so-called calcite seas) sea urchins with decreased skeletal magnesium contents were more susceptible to damage due to physical disturbances, predation and post-mortem taphonomic processes. Increased skeletal hardness of echinoids from the so-called aragonite seas is expected to enhance their taphonomic potential, thus, to some extent, mitigates the preservation bias related to increased solubility of high-magnesium calcite.

Impact of deposition pressure on the structural, nanomechanical, and tribological properties of δ-TaN coatings deposited via magnetron sputtering on Ti6Al7Nb alloy

In the present study, δ-TaN thin films were deposited by reactive magnetron sputtering (physical vapour deposition) on Ti6Al7Nb alloy by varying the deposition pressure (0.8–0.2 Pa). Their crystalline structure, chemical composition, surface roughness, and surface morphology were investigated by using grazing incidence X-ray diffraction, energy dispersive spectroscopy, scanning probe microscope, and field emission scanning electron microscopy (FESEM), respectively. Structural analysis results confirmed the deposition of cubic δ-TaN thin films along the (111) basal plane; moreover, spherical dome-like surface morphology was observed by FESEM. Further, to analyze the nanomechanical properties of the deposited δ-TaN coatings, such as hardness (H) and modulus (E), scratch tests were performed utilizing the nanomechanical system. Moreover, friction and wear properties of the coating and bare sample (substrate) were investigated on nano-tribometer equipment using a rotary ball-on-disk type configuration. The stainless steel (SS-316) and silicon nitride (Si3N4) balls were used as the counter materials for the tribological tests. The observations of nanomechanical tests revealed that H (GPa), E (GPa), and H/E ratio values increased from 11.83 to 28.30 GPa, 176.02 to 248.45 GPa, and 0.06 to 0.11, respectively, with the decrease of the deposition pressure. In the scratch test, the highest critical load (cohesion failure) was found for δ-TaN coating deposited at the lowest deposition pressure (0.2 Pa). Tribological results of δ-TaN coatings demonstrated average coefficient of friction (COF) value ranges between 0.066–0.092 and 0.072–0.029 against steel and Si3N4 balls, respectively. The wear rate values were observed to vary from 8.15 × 10−5 to 7.56 × 10−6 and from 1.77 × 10−3 to 8.99 × 10−6 against steel and Si3N4 balls, respectively. Generally, the average COF and wear rate decreased against 316 SS and Si3N4 balls as the deposition pressure of coatings decreased. However, the coating deposited at 0.8 and 0.6 Pa against Si3N4 ball showed early delamination of the coating, resulting in the sudden fluctuation in COF plots and higher wear rate in the range of 10−3 mm3/N.m.

Differentiation of Spiral Ganglion Neurons from Human Dental Pulp Stem Cells: A Further Step towards Autologous Auditory Nerve Recovery.

The degeneration of spiral ganglion neurons (SGNs), which convey auditory signals from hair cells to the brain, can be a primary cause of sensorineural hearing loss (SNHL) or can occur secondary to hair cell loss. Emerging therapies for SNHL include the replacement of damaged SGNs using stem cell-derived otic neuronal progenitors (ONPs). However, the availability of renewable, accessible, and patient-matched sources of human stem cells is a prerequisite for successful replacement of the auditory nerve. In this study, we derived ONP and SGN-like cells by a reliable and reproducible stepwise guidance differentiation procedure of self-renewing human dental pulp stem cells (hDPSCs). This in vitro differentiation protocol relies on the modulation of BMP and TGFβ pathways using a free-floating 3D neurosphere method, followed by differentiation on a Geltrex-coated surface using two culture paradigms to modulate the major factors and pathways involved in early otic neurogenesis. Gene and protein expression analyses revealed efficient induction of a comprehensive panel of known ONP and SGN-like cell markers during the time course of hDPSCs differentiation. Atomic force microscopy revealed that hDPSC-derived SGN-like cells exhibit similar nanomechanical properties as their in vivo SGN counterparts. Furthermore, spiral ganglion neurons from newborn rats come in close contact with hDPSC-derived ONPs 5 days after co-culturing. Our data demonstrate the capability of hDPSCs to generate SGN-like neurons with specific lineage marker expression, bipolar morphology, and the nanomechanical characteristics of SGNs, suggesting that the neurons could be used for next-generation cochlear implants and/or inner ear cell-based strategies for SNHL.

Exploring the Effect of Aluminium Solute Atoms on Nanomechanical Properties of Copper‐Aluminium System using Nanoindentation

In this work, nanomechanical properties for Cu and Cu–Al (where Al = 2, 4, 6, and 8 wt%) alloys are determined using nanoindentation with Berkovich tip. Nanoindentation experiments are performed using trapezoidal load function where maximum load (Pm) varies from 1000 to 9000 μN at an equal interval of 1000 μN by maintaining equal loading and unloading rate. It is found that Cu8Al sample shows lower depth of penetration (h) at any load (P) in comparison to other samples due to more pinning of dislocations or hinderance of the dislocation movement by solute (Al) atoms during nanoindentation deformation. In addition, it is observed that the recovery is maximum for Cu8Al sample among all samples; however, this recovery is reducing with the increasing Pm for all samples. Thereafter, the elasticity and plasticity index are calculated from the area under the P–h curves, which shows that the elastic index is maximum for Cu8Al and minimum for Cu. Furthermore, the nanomechanical properties (reduced elastic modulus [Er] and hardness [H]) are reported for all samples and significant indentation size effect is observed for Cu8Al due to dislocation structure during deformation.

Nanomechanical resilience and thermal stability of RSJ2 phage

As the world moves toward a green economy and sustainable agriculture, bacterial viruses or bacteriophages (phages) become attractive biocontrol agents for controlling crop diseases. Effective utilization of phages in farms requires integrated knowledge of crops, pathogens, phages, and surroundings. Phages must encounter environmental fluctuations, including temperature, and must remain infectious for successful bacteria lysis. This work studied a soilborne RSJ2 phage discovered in Thailand, which can eliminate Ralstonia solanacearum, causing bacterial wilt disease in chili. We investigated how phage infectivity and nanomechanics responded to thermal changes. The plaque-based assay showed that the infectivity of the RSJ2 phage was stable within 24–40 °C, an average temperature fluctuation in tropical regions. The structural examination also showed that the phage remained intact. The nanomechanical property of the phage was inspected by the atomic force microscopy-based nanoindentation. The result revealed that the phage stiffness within 24–40 °C was statistically similar (0.05–0.06 N/m). Upon heating at 40 °C for 1, 5, and 10 h and resting at 25 °C, the stiffness of the phage particles increased to 0.09–0.11 N/m (54–83% increase). The stiffness results suggest structural adaptation of the protein subunits as a response to thermal alteration. The study exhibits that the phage structure is highly dynamic and can nanomechanically respond to varying temperatures. The phage stiffness may reveal insight into phage adaptation to environmental factors. Equipped with the knowledge of phage infectivity, structure, and nanomechanics, we can design practical guidelines for effective phage usage in farming and propelling green and safe agriculture.

MICROSTRUCTURE, CHEMICAL COMPOSITION, AND NANOMECHANICAL PROPERTIES OF ARC-PVD ZrTa/ZrTaO2 BILAYER COATINGS

The results of vacuum-arc deposition of thin bilayer ZrTa/ZrTaO2 coatings on the surface of titanium dental implants, AISI-316L stainless steel are presented. The structure, phase and chemical composition of deposited coatings have been investigated by means of scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and X-ray diffraction analysis XRD. Nanomechanical properties have been investigated by nanoindentation method. The obtained results can be useful for optimization of implant surfaces to prevent corrosion and mechanical failure, thereby improving osseointegration.

New insights into the deformation mechanism of orientation-dependent nanoindentation behaviours

Nanoindentation has been widely used to access the micro-/nanomechanical properties of materials. However, the contribution of micro-texture evolution to the anisotropic surface topography, the correlation of dislocation density characteristics with the orientation-dependent plastic volume, and the specifics of inherent slip activities, are still not fully elucidated up to now.Herein, nanoindentation simulations were performed on (001)-, (101)- and (111)-oriented single-crystal aluminium. Dominant slip systems are exactly determined for each surface pile-up for the first time. Moreover, lattice rotation facilitates the formation of pile-ups. The anisotropic plastic volume is controlled by the preference of intrinsic dislocation movement. In (001) sample, dislocations prefer to propagate along the free surface instead of into the depth of the sample, causing its most obvious pile-ups.

Elasticity Mapping of Colloidal Glasses Reveals the Interplay between Mesoscopic Order and Granular Mechanics.

Colloidal glasses (CGs) made of polymer (polymethylmethacrylate) nanoparticles are promising metamaterials for light and sound manipulation, but fabrication imperfections and fragility can limit their functionality and applications. Here, the vibrational mechanical modes of nanoparticles are probed to evaluate the nanomechanical and morphological properties of various CGs architectures. Utilizing the scanning micro-Brillouin light scattering (µ-BLS), the effective elastic constants and nanoparticles' sizes is determined as a function of position in a remote and non-destructive manner. This method is applied to CG mesostructures with different spatial distributions of their particle size and degree of order. These include CGs with single-sized systems, binary mixtures, bilayer structures, continuous gradient structures, and gradient mixtures. The microenvironments govern the local mechanical properties and highlight how the granular mesostructure can be used to develop durable functional polymer colloids. A size effect is revealed on the effective elastic constant, with the smallest particles and ordered assemblies forming robust structures, and classify the various types of mesoscale order in terms of their mechanical stiffness. The work establishes scanning µ-BLS as a tool for mapping elasticity, particle size, and local structure in complex nanostructures.

Development of Functionally Graded HA-Al2O3-TiO2 Composite Coating on Ti Alloy: Microstructural Characterization, Nano-mechanical Properties, and Wear Behavior

Development of Functionally Graded HA-Al2O3-TiO2 Composite Coating on Ti Alloy: Microstructural Characterization, Nano-mechanical Properties, and Wear Behavior