Changes In Microstructure Properties Research Articles

Effect of different starches in batter formulation on oil content and associated quality attributes of fried chicken nuggets

Persistent consumption of heavily fried and breaded foods over an extended period may have the potential to contribute to the development of cardiovascular, cerebrovascular diseases, and elevated blood pressure. The potential of coating using native starches (cassava, sweet potato, and corn) in batter formulation to reduce oil uptake as well as their effects on other quality attributes (moisture, colour and textural properties) were investigated. The chicken nuggets coated with batter from different starches were fried at 170 °C for 5 to 25 min. Scanning electron microscopy (SEM) was used to study changes in microstructural properties of fried chicken nuggets samples at different time intervals. The chicken nuggets coated with batter from sweet potato starch had lower oil (13.09%) and moisture (30.49%) contents compared with those coated with other starches. The SEM revealed that longer frying duration produced chicken nuggets with fewer gas cells and pores and subsequently lower oil content. There are changes in the colour and textural properties of the fried chicken nuggets irrespective of the starches used in batter formulation. Application of starches in batter formulation at different frying time affected some quality attributes of fried chicken nuggets with sweet potato starch having better attributes when compared with others.Graphical

Electrochemistry-Based Diagnosis of Li Plating for Fast-Charging Li-Ion Batteries

Recent innovations in battery technologies have facilitated the development and widespread use of electric vehicles (EVs), by increasing the energy density of batteries while lowering their cost. Despite the rapid growth of the EV market, the long charging time of lithium-ion batteries (LIBs) remains as a major obstacle for expanding customer acceptance of EVs. Typically, graphite-based anodes in the state-of-the-art LIBs suffer from Li plating under fast-charging conditions, which causes severe performance degradations and early cell failure of batteries. To prevent the Li plating-induced failure, extensive research efforts have been devoted to developing diagnostic methods capable of detecting Li plating. The electrochemical analysis of Li plating enables non-destructive, in operando detection without complicated experimental procedures or special equipment.Herein, we present a non-destructive method for detecting Li plating during fast-charge cycling by analyzing current transients during the constant-voltage charging step, based on electrochemical battery models. Three-dimensional (3D) and pseudo-two-dimensional (P2D) battery models are employed to predict the electrochemical behavior of full cells under fast-charging conditions. 3D model enables the evaluation of local electrochemical properties, such as local reaction current densities and electrode potentials, which are largely affected by the microstructure of the electrode. Furthermore, P2D models are employed to investigate the effect of changes in microstructural properties (e.g., porosity and fraction of active surface of the graphite anode) on electrochemical behavior of full cells.For 3D modeling, the 3D Voronoi tessellation and Catmull-Clark algorithm are employed to construct the model geometry of graphite anodes. 3D modeling results predict that upon fast-charging, the charge-transfer potential on the top surface of graphite anode rapidly drops below 0 V vs. Li/Li+, triggering Li plating. To extract the electrochemical signals of Li plating, the fast-charging behaviors of full cells are investigated by using the P2D model with a partially reversible Li plating–stripping reaction. In specific, the constant-current and constant-voltage (CC-CV) charging process of the full cells with graphite anodes is simulated with Li plating-induced degradation modes; reduction of (i) interparticle pores, (ii) active surface area for Li intercalation reaction, and (iii) cyclable Li amount. Modeling results demonstrate that an inflection point appears in the current transient curve, and it shows a positive shift when the Li plating-induced degradation occurs. Electrochemical tests and microstructural analyses further confirm the validity of proposed electrochemical detection of Li plating. This study provides an effective strategy to design electrochemical methods for Li plating detection during fast-charging batteries based on electrochemistry-based models.

INVESTIGATION OF MICROSTRUCTURE OF AA7075 ALLOYS AFTER SEVERE PLASTIC DEFORMATION APPLICATION

The aim of this study is to investigate the change of microstructural properties of AA7075 alloys after severe plastic deformation. Severe Plastic Deformation is a process used to improve the properties of the material by creating intense plastic deformations on the material surface. Equal channel angular compression molding (ECAP) was used for the severe plastic deformation process in our study. AA7075 alloy samples were primarily prepared for severe plastic deformation treatment. Then, the microstructural properties of the samples were investigated using various imaging techniques such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The research results showed that significant microstructural changes occurred in AA7075 alloys after the severe plastic deformation process. The SPD process improved the mechanical properties of the material by transforming the crystalline structures of the material into a fine-grained structure. In addition, it was observed that deformation lines and pits occurred on the surface of the samples after the SPD process. It is seen that the SPD treatment increases the mechanical properties of the material such as strength, hardness and durability. Therefore, this study is an important step towards the development of the alloy's use in various industries.

Study of synergistic effect of fly ash and superabsorbent polymers on properties of cement pastes

The main goal of this study is to observe changes in microstructural properties and the mutual interaction of cement pastes containing superabsorbent polymers (SAPs) and fly ash. SAP is a type of hydrogel additive, able to absorb large amounts of liquid in its structure. In cement-based materials, it is often used in the early stages of matrix hydration to absorb excess mixing water and to release it in the later stages, which is even more desirable when the material is exposed to higher temperatures. Another research goal is a partial substitution of binder (Portland cement) by the energy by-product of high-temperature ash, produced by the combustion of brown coal. A further goal is the observation of the interactions of these binders with the SAPs on the microstructural scale. For this purpose, computed tomography (CT), X-ray diffraction (XRD), differential thermal analysis (DTA), and scanning electron microscopy (SEM) were performed. Basic physical and mechanical properties such as compressive strength, flexural strength, and bulk density were also determined. In the early stages of hydration, viscosity and chemical shrinkage were determined. From the results obtained, it is obvious that the presence of SAPs has a significant impact on the properties of cement pastes. From the two tested SAPs, SAP HM has a positive effect on volume stability and the flexural strength of the composite. The results of the mineralogical composition showed that the effect of SAP incorporation influences the crystallization of portlandite, alite, belite, and calcite. SEM analysis confirmed the results of XRD analysis and proved that hydration products can grow into SAP cavities. It is clear from the evaluation of the pore structure that SAPs increase the porosity of cement composites. The admixture of high-temperature fly ash has a positive effect on reducing the volumetric changes of mixtures. The mechanical parameters of the composite with fly ash were similar to that of the reference test specimens.

Surface Functionalization of Sugarcane-Bagasse-Derived Cellulose Nanocrystal for Pickering Emulsion Gel: Microstructural Properties and Stability Efficiency.

An environmentally friendly Pickering stabilizer was developed by upcycling sugarcane bagasse (SCB) into a cellulose nanocrystal (CNC), which was subjected to surface modification by using quaternary ammonium compound to enhance its amphiphilic characteristics. The changes in microstructural properties of modified cellulose nanocrystal (m-CNC), such as surface functional group, thermal stability, surface morphology, elemental composition, and particle size distribution were investigated. Results indicated the success of quaternary ammonium compound grafting with the presence of a trimethyl-alkyl chain on the cellulose structure, while the m-CNC preserves the needle-like nanoparticles in length of ~534 nm and width of ~20 nm. The colloidal profile of m-CNC-stabilized oil-water emulsion gels with different concentrations of m-CNC (1-5 wt%), and oil:water (O:W) ratios (3:7, 5:5, 7:3) were examined. The emulsion gel stability study indicated that the optimal concentration of m-CNC (3 wt%) was able to stabilize all the emulsion gels at different O:W ratios with an emulsion index of >80% for 3 months. It is the minimum concentration of m-CNC to form a robust colloidal network around the small oil droplets, leading to the formation of stable emulsion gels. The emulsion gel with O:W ratio (3:7) with 3 wt% of m-CNC rendered the best m-CNC-oil-droplets dispersion. The m-CNC effectively retained the size of oil droplets (<10 μm for 3 months storage) against coalescence and creaming by creating a steric barrier between the two immiscible phases. Furthermore, the emulsion gel exhibited the highest viscosity and storage modulus which was able to prevent creaming or sedimentation of the emulsion gels.

The microstructure and mechanical properties of Ce2O3 reinforced WC-Cu-10Ni-5Mn-3Sn-1.5TiC cemented carbides fabricated via pressureless melt infiltration

Microstructure and mechanical properties of WC-Cu-10Ni-5Mn-3Sn-1.5TiC cemented carbides fabricated by pressureless melt infiltration at 1200 °C for 90 min with different Ce2O3 contents (0 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt%, and 1.0 wt%) were investigated. Ce2O3 accelerated the decomposition and dissolution of WC. The melt infiltration reaction products of high carbon solid solution, such as W, Ni2W4C, and (Ti,W)C1-X are precipitated in binder alloys. High carbon solid solution gradually decreased or even disappeared, and W, Ni2W4C, and (Ti,W)C1-X seemed to grow with the increase of Ce2O3 contents. Considering the influence of decomposition and dissolution of WC and the formation of new phases, the size of WC particles decreased while the surface morphology of WC slowly changed from round and blunt to sharp-angle shaped, and the contiguity value of WC particles first decreased and then increased. The changes in microstructural properties of cemented carbides as a function of Ce2O3 inevitably led to the change in mechanical properties. The sample with 0.4 wt% Ce2O3 additions had the highest hardness (94.8 HRA). The highest values of impact toughness and TRS in 0.6 wt% Ce2O3 cemented carbides were 7.15 J cm−2 and 1977.8 MPa, respectively.

Microstructure and compressibility evolution of sulfate saline compacted loess under drying-wetting cycles

Soil salinization not only can induce environmental problems but also cause notable changes in the engineering performance of soil, especially the compacted loess that is often exposed to drying-wetting (D-W) cycles in Northwest China. To explore the changes in compression behavior of the saline compacted loess under D-W cycles, a series of the oedometer tests were conducted on compacted loess samples with different D-W cycles and sodium sulfate content. In addition, the changes in microstructural properties of the loess samples were also investigated by scanning electron microscope (SEM) tests. The results demonstrate that the compressibility coefficient of the loess samples increases with D-W cycles and tend to stabilize after three cycles, while varies linearly with salt content. The compressibility deterioration equation for the based on the compressibility coefficient was then established considering both D-W cycles and salt content, which can well predict the compressibility deterioration of saline compacted loess under D-W cycles. Due to the repeated gasification and liquefaction of pore water and the repeated dissolution and crystallization of sodium sulfate, the skeleton of saline compacted loess with higher salt contents or more D-W cycles tends to loosen, which greatly enhances the effective connectivity of the pores and leads to the deterioration of compressibility. Finally, the compressibility deterioration ratios due to D-W and salt erosion were discussed by decoupling analysis. These findings can provide references for the engineering practice in loess areas.

The Effect of Surface Treatment on Structural Properties of CVD Diamond Layers with Different Grain Sizes Studied by Raman Spectroscopy.

Extensive Raman spectroscopy studies combined with scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) measurements were performed to investigate structural and chemical changes in diamond layers deposited by chemical vapour deposition (CVD) upon post-growth treatment with hydrogen. The aim of this study is to characterize the changes in micro-structural properties of diamond layers with different grain sizes and different contents of sp2 carbon phase. Hydrogenation or oxidization of diamond layer surface is often performed to modify its properties; however, it can also strongly affect the surface structure. In this study, the impact of hydrogenation on the structure of diamond layer surface and its chemical composition is investigated. Owing to their polycrystalline nature, the structural properties of CVD diamond layers can strongly differ within the same layer. Therefore, in this project, in order to compare the results before and after hydrogen treatment, the diamond layers are subjected to Raman spectroscopy studies in the vicinity of a T-shape marker fabricated on the surface of each diamond layer studied.

Performance of cementless binders produced from industrial waste products in strong acid

There is a growing demand for alternative low carbon binders. For these relatively new binder systems to be well received in industry it is important that detailed understanding of their durability performance is available. This paper investigates the hydrochloric acid resistance of geopolymer binders containing 100% fly ash and various blends of fly ash and blast furnace slag. Both physical and microstructural properties changes were examined to assess acid resistance and the leaching behaviour was also monitored. As the slag content of geopolymer binders increased, the resistance to hydrochloric acid also increased, evidenced by the reduced mass and strength loss observed. Findings also illustrate that geopolymer binders have hydrochloric acid resistance which exceeds that of traditional Portland cement binders in terms of the mass losses observed. The process of hydrochloric acid attack for each binder is also studied. • Fly ash/slag geopolymers had improved resistance to HCl than Portland cement. • As the slag content increased the resistance of geopolymers also increased. • Neat fly ash mixes had high apparent acid penetration but low surface deterioration. • Fly ash/slag geopolymers underwent decalcification of C-A-S-H type gel. • Neat fly ash mixes experienced dealumination of N-A-S-H gel.

Correlation between Microstructure and Mechanical Properties of 6063-O Aluminum Alloy and IS 2062 Mild Steel under High Strain Rate Shear Loadings

An experimental study for the characterization of 6063-O aluminum alloy and IS 2062 mild steel materials under high strain rate shear loading was conducted. A microstructural study of the tested samples was performed to understand the correlation between the microstructure and mechanical properties. Aluminum alloy 6063-O and IS 2062 mild steel specimens were subjected to shear strain rates in the range of 120-200 and 100-280 s−1, respectively. An enhancement in the shear strength is observed for both the materials tested at high strain rates. The microstructural study on the fracture surfaces of the aluminum alloy and the mild steel test coupons was carried out using scanning electron microscopy (SEM). Grain size refinement was observed with increasing strain rate indicating a strong dependence of mechanical properties on the grain size evolution during testing. Changes in microstructural properties at different shear strain rates and its effect on the mechanical properties are presented.

Investigation on surface sulfate attack of nanoparticle-modified fly ash concrete.

Sulfate attack on concrete structures is a major durability concern wherein concrete interacts with marine water, swamp water, groundwater, sewage water, freshwater, etc. In this study, the supplementary cementitious materials such as fly ash (FA) and nanoparticles are together incorporated into conventional concrete aiming to enhance the resistance of concrete against the penetration of sulfates. The present work is focused to understand the degradation in FA concrete modified with nanoparticles by surface sulfate attack. Concrete mix such as FA and FA modified with 2 wt% nano-TiO2 (FAT), nano-CaCO3 (FAC), and 1:1 ratio of nano-TiO2 to nano-CaCO3 (FATC) was fabricated. The specimens were exposed in 3% of ammonium and sodium sulfate for 90 days. The deterioration effects and changes in microstructural properties in all the specimens were comparatively studied. Results showed FAT, FAC, and FATC concrete have been deteriorated in ammonium and sodium sulfate solution compared with FA concrete. Partial replacement of cement with fly ash decreases the quantity of freely available reactive aluminates. Consumption of free lime by the fly ash prevents to react with sulfate. The enhanced properties of fly ash concrete against sulfate attack could be achieved with less C3A content thus reducing the available Ca(OH)2 and reducing the possibility of development of deleterious ettringite and gypsum.

Focal white matter disruptions along the cingulum tract explain cognitive decline in amnestic mild cognitive impairment (aMCI)

White matter abnormalities of the human brain are implicated in typical aging and neurodegenerative diseases. However, our understanding of how fine-grained changes in microstructural properties along white matter tracts are associated with memory and cognitive decline in normal aging and mild cognitive impairment remains elusive. We quantified tract profiles with a newer method that can reliably measure fine-grained changes in white matter properties along the tracts using advanced multi-shell diffusion magnetic resonance imaging in 25 patients with amnestic mild cognitive impairment (aMCI) and 23 matched healthy controls (HC). While the changes in tract profiles were parallel across aMCI and HC, we found a significant focal shift in the profile at specific locations along major tracts sub-serving memory in aMCI. Particularly, our findings depict white matter alterations at specific locations on the right cingulum cingulate, the right cingulum hippocampus and anterior corpus callosum (CC) in aMCI compared to HC. Notably, focal changes in white matter tract properties along the cingulum tract predicted memory and cognitive functioning in aMCI. The results suggest that white matter disruptions at specific locations of the cingulum bundle may be a hallmark for the early prediction of Alzheimer’s disease and a predictor of cognitive decline in aMCI.

Performance Evaluation of Crumb Rubber Asphalt Modified with Silicone‐Based Warm Mix Additives

This research was conducted to elucidate better understanding of the performance of crumb rubber asphalt modified with silicone‐based warm mix additives. Two different silicone‐based warm mix asphalt (WMA) additives (herein Tego XP and Addibit) were used to prepare crumb rubber modified (CRM) warm mix asphalt binders. The viscosity of these CRM binders was measured at different temperatures and shearing rates. Furthermore, softening point and penetration tests, Multiple Stress Creep Recovery (MSCR), Time Sweep (TS), Atomic Force Microscopy (AFM), Frequency sweep (FS), and Fourier Transform Infrared (FTIR) tests were also conducted on prepared samples. Based on these robust and rigorous laboratory experiments, it was established that viscosity of CRM binders was reduced by addition of Tego XP and Addibit WMA additives. However, WMA additives had different influence on rheological properties of the binder. CRM binder with Tego XP improved resistance to rutting of the binders but would degrade the fatigue performance. On the contrary, viscoelastic continuum damage (VECD) model results and those of phase angle approach revealed that the binder with Addibit improved resistance to fatigue cracking of the binders but had no adverse effects on high temperature rutting performance. FTIR test results established a presence of polydimethylsiloxane (PDMS) in CRM binders with Tego XP and Addibit. PDMS is a well‐known hydrophobic organic and inorganic polymer that is water repellent; therefore, binders containing these silicone‐based warm mix additives could be beneficial in resisting moisture damage in asphalt binders and mixtures. Morphology of CRM binders with and without WMA revealed good distribution of the rubber particles in asphalt binder matrix. Further addition of WMA increased surface roughness of the binder, which can be correlated to changes in microstructure properties of the binder. Therefore, the study concluded that addition of Tego XP and Addibit reduces viscosity and improves mechanical properties of the asphalt binder.

Characterization of laser bending of SUS304L/C11000 clad sheets

Laser bending process is an advanced method for manufacturing of various bends on different types of materials. The combination of different metals using clad sheets makes it possible to achieve a wide range of tailored properties. Laser beam irradiation over these materials creates extreme temperature gradients in the thickness direction that can lead to bending deformation and changes in microstructural properties. In this study, laser bending of SUS304L/C11000 clad sheet is characterized using 200 W ytterbium fiber laser. The effects of laser power, scanning velocity and beam diameter on the bending angle are investigated, and metallographic studies, as well as tensile, fatigue and hardness tests, are conducted on SUS304L/C11000 clad sheets that have been exposed to laser irradiation with different number of passes. The specific characteristics obtained from this study provide valuable information for the bendability of SUS304L/C11000 clad sheet and evolution of microstructure and mechanical properties after laser bending.

Seed-fused ZSM-5 nanosheet as a superior MTP catalyst: Synergy of micro/mesopore and inter/external acidity

Abstract ZSM-5 nanosheet (NS) has an optimal diffusivity due to b-axis oriented two-dimensional structure, but the extra large external acidity results in the deactivation of the catalyst in methanol to propylene (MTP) reaction. The seed-fused ZSM-5 nanosheets (CNS-x) were synthesized by a seed induced method, the performance of samples was compared with one without seed. Further, the B-incorporation sample (B-CNS-5) was prepared with 5 wt% seed and boron acid. Revealing the importance of fusion effect of ZSM-5 seed on the nanosheet, especially the change in microstructure properties and its structure-effect relationship, which is not explicitly documented in previous work. With the seed amount increasing from 5 to 30 wt % in the gel, the crystallization time is largely shortened, along with the change in the resulting nanosheet, such as reduction of particle size and acid strength/external surface acidity, an increase of over 50% micropore volume. The CNS-x samples perform longer catalytic lifetime (168–226 h) compared to NS (103 h). CNS-5 displays an extremely high selectivity to propylene (C = 3) ∼54% and total light olefins (C = 2-C = 4) of∼84%. A super sample B-CNS-5 exhibits longest lifetime (302 h), achieving highest C = 3 yield due to change in the acid sites distribution and increase of extra weak acid sites. For the converted methanol (g/gcatalyst), the result is B-CNS-5 (966) > CNS-5 (525)> NS (324). In converse, the average coke selectivity (Sav, C) is B-CNS-5 (0.18‰)

Competing growth of titanium nitrides and silicides in Ti thin films processed in expanding microwave plasma: Morphology and microstructural properties

The diffusion of nitrogen into Ti silicide films allows the performance of complementary metal oxide semiconductor (CMOS) components to be improved. In this work, the thermochemical treatment is carried out in an expanding microwave plasma reactor using (Ar-33%N2-1%H2) gas mixtures. This process promotes the chemical reactions on the surface of metals. The diffusion of nitrogen into the film is improved by the reducing effect of NHx and/or H species towards passive layers such as oxides which form a barrier of diffusion in the surface layers during the process. The simultaneous formation of Ti nitrides and silicides at the surface and at the film-substrate interface, respectively gives rise to two competing processes which result in the growth of the Ti nitride phase at the expense of the Ti silicide phase at a critical temperature of 800°C. This paper reports on a comprehensive analysis of the evolution of TiSi2 and TiN phases and microstructural properties of films by means of X-ray diffraction, Raman spectroscopy, transmission electron microscopy and selected area electron diffraction investigations. Square shaped crystals of TiN are identified on the top of round shaped crystals of TiSi2. The growth of the TiN phase at the expense of TiSi2 induces a catastrophic decrease of the intensity of the (040) diffraction line of TiSi2 and a huge increase of the (220) reflection line of TiN. The microstructural properties changes during the process such as the formation of TiN crystals of nanometric size in the bulk of the TiSi2 phase as well as the migration of free Si which epitaxially grows at the film-substrate interface have been evidenced by very detailed investigations for the first time. The results are related to the mechanism of formation of TiN from the reaction between TiSi2 and nitrogen.

Milling effect on the microstructural and hydrogenation properties of TiFe0.9Mn0.1 alloy

TiFe is a remarkable hydrogen storage alloy thanks to its reversibility at ambient temperature and pressure, high capacity and low cost. However, activation and sorption kinetics should be improved for practical applications. The effect of mechanical milling on the morphological, structural and hydrogen sorption properties of powdered TiFe0.9Mn0.1 alloy has been determined. Pristine alloy powder with mean particle and crystal sizes of 45 μm and 30 nm, respectively, was used as a reference. The pristine powder was ball milled for different times up to 5 h leading to significant changes in microstructural properties already observed after 0.5 h of milling. For such short milling time, the particle and crystal sizes decrease by a factor of five and three, respectively, with minor formation, if any, of amorphous phases. These microstructural changes promote a reduction of the activation time towards hydrogen absorption by a factor of five and enhance sorption kinetics. Besides, the hydrogen thermodynamic properties are slightly modified leading to sloping plateau pressures and hydride stabilization. These modifications may lead to a lowering of apparent desorption rates which should be carefully considered for the use of milled TiFe-type alloys in practical applications.

Combined Experimental and Numerical Analysis of Surface-Modified Solid Oxide Fuel Cell Cathodes

In this study, the effects of surface modification on the performance of composite solid oxide fuel cell (SOFC) cathodes are investigated through a series of experiments and relevant multi-physics simulations. Experimentally, the LSM/YSZ composite cathodes of commercial fuel cells are surface-treated with various electrocatalysts, and datasets of both polarization curves and electrochemical impedance spectra are collected. The multi-physics simulations consider both charge conservation and species transportation, as well as a multi-step oxygen reduction reaction (ORR) mechanism with parallel pathways. The numerical simulations are developed and then calibrated against data from baseline cells. Based on changes in microstructural properties and rate constants, the performance of the modified fuel cells is then predicted using reaction mechanism parameters recalibrated from experimental data. Analysis is also performed to separate and quantify the effect on cell performance from the changes in microstructural properties and reaction mechanism parameters resulting from surface modification. This study provides insights into the tuning of electrochemical processes when modifying the surface of cathodes and guides further performance improvements.

Combined Experimental and Numerical Analysis of Surface-Modified Solid Oxide Fuel Cell Cathodes

In this study, the effects of surface modification on the performance of composite solid oxide fuel cell (SOFC) cathodes are investigated through a series of experiments and relevant multiphysics simulations. Experimentally, the LSM/YSZ composite cathodes of commercial fuel cells are surface-treated with various electrocatalysts, and datasets of both polarization curves and electrochemical impedance spectra are collected. The multiphysics simulations consider both charge conservation and species transportation, as well as a multi-step oxygen reduction reaction (ORR) mechanism with parallel pathways. The numerical simulations are developed and then calibrated against data from baseline cells. Based on changes in microstructural properties and rate constants, the performance of the modified fuel cells is then predicted using reaction mechanism parameters recalibrated from experimental data. Analysis is also performed to separate and quantify the effect on cell performance from the changes in microstructural properties and reaction mechanism parameters resulting from surface modification. This study provides insights into the tuning of electrochemical processes when modifying the surface of cathodes and guides further performance improvements.

Inert atmosphere processing of hydroxyapatite in the presence of lithium iron phosphate

The present study describes sintering behaviour of hydroxyapatite (HAp) upon addition of lithium iron phosphate (LFP) (1–10 wt.%) system in inert (Ar) atmosphere. The interaction between materials and melting of LFP influenced early and intermediate stages of HAp sintering, shifting the densification curves towards low-temperature side. Analysis of densification process indicated significant differences upon LFP addition. The reaction mechanism that assumes the initial interaction between phosphates from LFP and calcium from HAp was proposed, generating calcium vacancies and contributing to HAp densification. Cross-sections of sintered samples showed changes in microstructural properties, with uniform atomic distribution and presence of Li2Fe3O4 spherical inclusions (200 nm) located at grain boundaries of calcium phosphate matrix. The Rietveld refinement analysis indicated changes in structural and microstructural parameters like crystallite size, anisotropy and microstructural strain of HAp upon LFP addition. Mechanical characterisation indicated improvements in fracture behaviour upon LFP addition.