Addition Of Nano-sized Particles Research Articles

Microstructural, texture, and crystallographic analysis of SiC particle incorporation in double-sided friction stir welding of dissimilar aluminium alloys

This paper investigates the impact of incorporating SiC nanoparticles into the welded interface joint of dissimilar aluminium alloys 2024 and 7075. Double-sided friction stir welding (DS-FSW) was performed to investigate the impact of added nanoparticles on the joint's mechanical properties and crack growth rate. Microstructural analysis of the fractured surface was conducted to assess the influence of nanoparticles on crack propagation, while field emission scanning electron microscopy (FESEM) was utilized to examine the grain size distribution across different weld zones. On analyzing the DS-FSW joint with SiC-reinforced particles using electron backscattered diffraction (EBSD), predominant shear texture components such as B/B̅ and C are observed. Additionally, there are deformed textures like Rotating cube (H) {001} <110> and F {111} <112>, along with recrystallization texture elements such as Goss {110} <001>, P {011} <112>, and Cube {001} <101>. Mechanical properties, determined through hardness and tensile tests, were compared between nanocomposite weldments and base metal to assess the improvement in mechanical properties following the inclusion of SiC particles. Crack growth tests were performed using compact test (CT) specimens at a maximum load of 5 kN and a stress ratio of R = 0.1. The addition of SiC nanoparticles to the joint area led to a significant decrease in grain size and an increase in hardness within the stir zone, compared to the base metal and samples without the powder. The tests revealed an approximately 62 % increase in tensile strength and a notable increase in microhardness of the weld zone of the aluminium alloy metal matrix composite (AAMMCs).

Corrosion resistance of squeeze cast magnesium alloy AM60-based hybrid nanocomposite coated with plasma electrolytic oxidation

ABSTRACT Plasma electrolytic oxidation (PEO) coating with NaAlO2 and KOH electrolytes was applied on the surfaces of as-cast AM60 (PEO-AM60), 7 vol.% Al2O3 fibres/AM60 (PEO-7FC) and 7 vol.% Al2O3 fibres + 3 vol.% Al2O3 nano-sized particles/AM60 (PEO-MHNC-7F3NP) to improve their corrosion resistance. The SEM and EDS analyses indicated that the PEO coating process formed a porous and dense layer on the substrate surface, as well as MgAl2O4 was the major concentration of the coating. The thickness of PEO coating on the 7FC and MHNC-7F3NP composites was slightly less than the coating on the AM60. The electrochemical corrosion tests were carried out in 3.5% NaCl aqueous solution at room temperature for investigating the corrosion behaviour of the as-cast AM60 and the composites after applying the PEO coating. The PEO coating increased the corrosion resistance of the AM60 alloy and the 7FC and MHNC-7F3NP composites to 342.81, 301.73 and 290.44 from 4.07, 2.08 and 1.88 kΩ∙cm2. By comparing the corrosion test results of the coated AM60 and the composites with those of the uncoated counterparts, it was found that the PEO coating significantly improved the corrosion resistance by up to 154 times. The addition of nano-sized particles barely increased the corrosion rate of the composite.

ZnO and Cu/ZnO-modified Magnesium orthopedic implant with improved osteoblast cellular activity: An in-vitro study

Mg-based biomaterials, due to their desirable mechanical integrity, natural bioabsorbability, and osteopromotive characteristics, are promising candidates for both orthopedic applications, such as the surgical fixation of injured musculoskeletal tissues, and cardiovascular applications like coronary artery stents. In the present study, nano- and micro-sized ZnO and Cu/ZnO bioactive particles were used to fabricate Mg-based biocomposites using friction stir processing (FSP). FSP resulted in significant microstructural modification in terms of grain refinement, uniform redistribution of secondary phase particles and homogenous dispersion of bioactive particles. Long-term biodegradation results through H2 evolution method illustrated that biodegradation rate of the bioabsorbable WE43 alloy was significantly reduced by addition of bioactive particles. In addition, fabricated biocomposites with addition of nano-sized particles resulted in lower biodegradation rate in comparison to those with micro-sized particles. Furthermore, uniform dispersion of bioactive particles resulted in superior in-vitro biocompatibility in contact with MC3T3-E1 mouse osteoblast cells. Mg–ZnO–N and Mg–Cu/ZnO–N biocomposites showed improved cell adhesion with elongated and spread morphology of MC3T3-E1 osteoblast cells. Live/dead staining and MTT assay indicated that number of healthy cells and cell viability after 24 h of incubation increased by uniform distribution of bioactive particles. Moreover, fabricated biocomposites with homogenous distribution of Zn2+ and Cu2+ ions showed higher ALP activity. Our findings propose that Mg–ZnO and Mg–Cu/ZnO biocomposites with homogenous dispersion of bioactive particles can be promising candidates for bone tissue regeneration applications.

Thermal optimization of MHD nanofluid over a wedge by using response surface methodology: Sensitivity analysis

It is well documented that heat transfer is enhanced with addition of nanosized particles in fluid. But, in a mechanical system there are variety of factors influences the heat transfer. Some factors are significant while others are not. In this paper, authors will discuss sensitivity of different input parameters such as Le, Nt and Nb on output responses Nux and Shx. To achieve this goal, the problem is modeled using basic conservation laws. The formulated model is a set of PDEs, which are converted to set of non-linear ODEs by using similarity transformation. Then these ODEs are solved numerically by using MATLAB built in package bvp4c and compared the numerical results with existing work and found good results. Sensitivity analysis is performed by employing RSM to determine the relationship between the input parameters such that 0.1≤Le≤1, 0.1≤Nt≤1 and 0.1≤Nb≤1 and the output responses (Nux and Shx). ANOVA tables are generated by using RSM. By using the ANOVA tables the correlations between input parameters and output response are developed. To check the validity of correlated equations, the residuals are plotted graphically and show best correlations between input parameters and output responses. The high values of R2=98.65 and AdjR2=97.43 for Nux and R2=97.83 and AdjR2=95.88 for Shx demonstrates the high validity of ANOVA results to perform sensitivity analysis. Finally, we have conducted a sensitivity analysis of the responses and came to the important results that Nt and Nb is most sensitive to Nusselt number and Sherwood number respectively.

Experimental study on the flexural, hardness, and tensile properties of pineapple and jute fiber-reinforced composite with SiC nanoparticles

This scientific investigation delves into the effects of minuscule particles created from a mixture of silicon and carbon, known as SiC nanoparticles, on the flexural, hardness, and tensile properties of composites made from fibers obtained from pineapple and jute. The researchers used a manual layering technique to make these composites, by blending varying amounts of fibers and SiC nanoparticles. Then proceeded to subject the composites to a series of tests to determine their resistance to bending, strength, and ability to bear tensile forces before breaking. The findings of the research reveal that the inclusion of SiC nanoparticles in the composites made from pineapple and jute fibers led to a significant improvement in their mechanical properties such as strength, stiffness, and toughness. The composites made using a greater proportion of fibers and nanoparticles exhibited the most substantial strength and stiffness. The addition of SiC nanoparticles also contributed to an increase in the composites' hardness, with the jute fiber composite displaying more improvement than the pineapple fiber composite. In terms of tensile strength and toughness, the composites with higher weight fractions of fibers and SiC nanoparticles displayed superior performance, with the jute fiber composite outperforming the pineapple fiber composite. These results suggest that utilizing SiC nanoparticles in composites made from natural fibers like pineapple and jute holds promise for producing premium quality materials that could serve multiple industries. Nevertheless, further studies are essential to refine the fabrication process and evaluate the long-term durability and performance of these composites. Overall, this research demonstrates the potential of using natural fiber-reinforced composites with nanoparticles to create sustainable, high-performance materials.

Electrodeposited FeCoNiWMo high entropy alloy/SiC nanocomposite coatings: Microstructure, mechanical properties and corrosion resistance

In this study, FeCoNiWMo/SiC high entropy alloy nanocomposite coatings were deposited at various contents of SiC nanoparticles in the bath. The effect of the addition of SiC nanoparticles on some properties of the electrodeposited FeCoNiWMo high entropy alloy matrix was evaluated. The morphological, elemental, and phase structure were analyzed by SEM, EDX, and XRD. For mechanical measurements, Vickers microhardness and pin-on-disk wear test were performed. A potentiostat-galvanostat device was used to determine corrosion resistance. The results show that the incorporation of SiC nanoparticles changes both the microstructure and morphology of the matrix from amorphous with FCC solid solution and nodular morphology to FCC solid solution with granular structure. By increasing the SiC content, the coatings showed improved microhardness, wear resistance, and corrosion performance. At optimum concentration (20 g/L), the nanocomposite exhibited the highest microhardness, wear resistance, and corrosion resistance.

Processing and evaluation of nano SiC reinforced aluminium composite synthesized through ultrasonically assisted stir casting process

Aluminium composites were synthesized through an ultrasonically assisted stir casting method by reinforcing 0.5 wt%SiC, 1.0 wt%SiC, 1.5 wt%SiC and 2.0 wt%SiC nanoparticles. Ultrasonication was carried out to the composite melt to refine the grain size and to achieve uniform nano-SiC dispersion in the aluminium matrix. Scanning electron microscopy (SEM) reveals the uniform dispersion of nano-SiC particles in the 0.5 wt%, 1.0 wt% and 1.5 wt% SiC reinforced compose. However, the X-Ray Diffraction (XRD) peaks confirm the Al2Cu intermetallic phases in the Al- 2.0 wt% SiC composite. The mechanical properties of the synthesized composites were significantly enhanced with the incorporation of SiC reinforcements and the maximum hardness and ultimate tensile strength (U.T.S) of 163 BHN and 431 MPa was attained for 1.5 wt% SiC reinforced composite. Nevertheless, the generated brittle agglomeration at 2.0 wt% SiC reinforcements decreases the mechanical properties of the composite due to the variation of thermal expansion coefficients between the matrix and the agglomerations. The yield strength of the fabricated Al– SiC composites was analyzed through different strengthening mechanisms. Results concluded that the yield strength contribution due to thermal mismatch is more influenced followed by the Orowan strengthening and grain refinement strengthening mechanism. In addition to this, the contribution of the strengthening mechanisms was found to be increased with the addition of SiC nanoparticles. Fractography investigation for the fractured tensile specimens reveals the ductile fracture for unreinforced aluminium and brittle fracture for the SiC-reinforced composites due to the presence of cleavage texture of the fractured surfaces of Al–SiC nanocomposites.

Effect of SiC Nanoparticle content on the properties of Ni-W-SiC nanocomposite thin films deposited by pulse current electrodeposition

In this study, pulse current electrodeposition (PC) was used to fabricate Ni-W-SiCthin films on mild steel plates, by utilizing a Watts-type Ni liquid that contained SiC nano-particles (NPs). The films deposited with 9 g/L SiC NP showed a smooth, finely granular, and remarkably homogeneous surface structure. All films showed SiC NPs equally distributed on the Ni-W-SiC-NPs surface regardless of the starting SiC NP content. The calculations revealed that the thicknesses of Ni-W-SiC-NPs films deposited at 9 and 12 g/L were ≈ 27.3 and ≈ 22.2 µm, respectively. Moreover, the crystallite sizes decreased as the SiC NPs’ level was changed up to 9 g/L. Film particles became smaller (≈66 nm) but enlarged to 85 nm when SiC NPs level was changed from 9 g/L to 12 g/L, respectively. The deposited layer demonstrated an increase in microhardness from 490.2 HV to 881.5 HV with the addition of SiC nanoparticles. However, the hardness values of the Ni-W-SiC-NPs films became lower as the SiC NPs levels were changed from 9 to 12 g/L. Additionally, films fabricated using 9 g/L of SiC NP level demonstrated a minimal corrosion current (equal to 1.536 ×10−6 µA/cm2). The corrosion resistance of the film deposited at 9 g/L was about 5.3 times that of the film obtained at 0 g/L, indicating an excellent corrosion resistance. The study can provide the corrosion protection for water or oil pipes, metal containers and agricultural machinery.

Mixed convection and non-linear thermal radiative analysis for Carreau-Yasuda nanofluid in an endoscope

The understanding of flow behaviour of non-Newtonian fluids in the presence of nanoparticles is of great interest from an industrial point of view. Bulk addition of nano-sized particles in fluid enhance thermo-physical properties of fluid which is of crucial importance to industries such as medicine, agriculture, electronics etc. Current study discusses thermophoretic diffusion and Brownian motion in peristaltic flow of Carreau-Yasuda nanofluid in tube-like (endoscopic) structure. Unlike many existing studies, the nonlinear radiation effect in the presence of heat and mass transfer i.e., mixed convection is considered. Dissipation, Joule heating and heat source, sink effects are modelled. The governing mathematical problems are numerically solved. Non-dimensionalization is achieved via use of lubrication approach and streamline functions. Quantities like velocity, temperature, concentration, heat transfer rate and trapping are addressed. Observing effects of Weissenberg number (We = 0.1 − 0.3) on fluid flow conclude that velocity as well as the size of trapped bolus increases as We is increased. Heat transfer rate enhances as temperature ratio parameter (θ1 = 0.3 − 0.7) is increased.

Grain refinement mechanism of SiC nanoparticles/Mg-9 wt. % Al composite investigated by sharp interface model at microscale and nanoscale

The grain refinement mechanism of Mg-9 Al (wt. %) alloy with the addition of SiC nanoparticles (NPs) is studied by a new strategy, a combination of experimental characterizations and sharp-interface model (SIM) simulations. Experiments show that the NPs near grain boundaries form a multilayer coating. Mean grain size is refined with the increase of NPs volume fraction. When the addition level of NPs is raised to 1.0 vol. %, the grain size decreases from 144 µm to 52 µm. The SIM simulations support that the primary interaction between NPs and the moving solid-liquid interface is NPs being pushed to the vicinity of grain boundaries. An equivalent solute-diffusion coefficient for the liquid phase is numerically determined based on iterative SIM simulations. Three possible refinement mechanisms are numerically examined at the microscale and nanoscale. It is the first SIM nanoscale simulation of the Gibbs-Thompson pinning effect. The growth restriction through blocking solute diffusion is identified as the dominant mechanism in the present experiment. The modification of thermal condition and the Gibbs-Thompson pinning effect is less critical. The Gibbs-Thompson pinning is the most promising mechanism for producing nanocrystalline metals with a strict dependence on the uniform dispersion of NPs. This work provides deep insights for controlling grain refinement of Mg matrix composites and shows a new synthetic way, the experiment-sharp interface model, to obtain equivalent solute-diffusion coefficients.

The structural, magnetic, and pinning features of Bi-2223 superconductors: Effects of SiC nanoparticles addition

In this research, the influence of Silicon Carbide nanoparticles (SiC-NPs) addition on the microstructure, superconducting, and pinning properties of (Bi, Pb)2Sr2Ca2Cu3O10+θ (Bi-2223) superconductors is comprehensively studied. The superconductors are synthesized by the sol-gel method and SiC-NPs are added up to 0.8 wt%. The X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) measurements are carried out for structural and morphological investigations. The superconductivity parameters such as intra-granular critical current density (JC, intra), inter-granular current critical density (JC, inter), transport critical current density (JC, t), and pinning force density (FP) are detected through DC- and AC-susceptibility, hysteresis loop, and transport measurements. The obtained results show that the 0.4 wt% addition of SiC-NPs improves the microstructure and the connectivity of grains as well as JC, inter, JC, intra, JC, t, and FP in the Bi-2223 superconductor. This research opens notable avenues for the use of synthesized Bi-2223 ceramics for electrical and industrial applications such as high-current energy storage, wires, and tapes.

Microstructural improvement of solar salt based MgO composites through surface tension/wettability modification with SiO2 nanoparticles

Composite phase change materials (CPMCs) are of particular interest in high-temperature thermal energy storage and waste heat utilization applications. To further enhance their thermal conductivity, CPCMs are often doped with nanosized particles (NPs). However, NP's influence the PCM's viscosity and wettability, significantly contributing to the CPCM's microstructure. Their effects on the PCM's viscosity have been extensively documented, but little has been done on its effect on wettability. To this end, we investigated, using a custom maximum bubble pressure tensiometer, the surface tension of the solar salt, as well as its contact angle on an MgO {1 0 0} surface with various concentrations of α-SiO2 NPs. At 0.5 wt%, an increase of 2.45% on the surface tension is observed, scaling up to 11.8% at 2.5 wt%. Contrary to the pure salt, in the presence of SiO2 the surface tension increases up to 400 °C followed by rapid decay, which is found to be related to NP agglomeration and subsequent sedimentation. In terms of contact angle NP addition leads to an increase at the melting point, but fully wetting conditions are attained at 390 °C independent of α-SiO2 content. To capitalize on this effect, MgO-Solar salt CPCMs without and with 1.0 wt % SiO2 are kept at 390 °C for 5 h. Silica addition leads to smaller leakage (mass loss), improved density (by 8.9%), improved porosity (by 18.9%), mean pore size reduction (by 100%) and enhanced thermal diffusivity (by 6.5%). This is suggested to be indirectly related to the surface tension/wettability modification through doping with polar NPs.

Thermogravitational convection of ferrofluid combined with the second law of thermodynamics for an open chamber with a heat-generating solid block under an influence of uniform magnetic field

The present numerical study scrutinizes the effect of uniform Lorentz force on the thermogravitational energy transport and entropy production of nanosuspension in an open domain with a heat-generating solid element. The left border is kept at low temperature (Tc) whilst the horizontal borders are assumed to be adiabatic. Finite volume method (FVM) is employed to work out the heat and mass transfer equations. For fixed value of Rayleigh number (Ra = 107), numerical analysis was optimized for wide ranges of nanoparticle volume fraction (ϕ = 1%–4%), thermal conductivity ratio of a heat generating body (k⁎ = 0.1–5), Hartmann parameter (Ha = 0–100), angle of inclined magnetic field (γ = 0°–90°) and non-dimensional temperature drop (Ω = 0.001–0.1). The numerical solutions were analyzed employing patterns of temperature and stream function as well as average Nusselt number and entropy lines. The outcomes indicated that, an increasing magnetic parameter Ha leads to reduction of mean Nu and the rate of entropy production. An addition of nano-sized particles enhances the energy transport and average entropy production for the system. It is also revealed that the maximum energy transport strength occurs at high thermal conductivity ratio (k⁎ = 5).

Entropy generation in MHD free convection of nanoliquid within a square open chamber with a solid body

PurposeThe study aims to investigate magnetohydrodynamics thermal convection energy transference and entropy production in an open chamber saturated with ferrofluid having an isothermal solid block.Design/methodology/approachAnalysis of thermal convection phenomenon was performed for an open chamber saturated with a nanofluid having an isothermal solid unit placed inside the cavity with various aspect ratios. The left border temperature is kept at Tc. An external cooled nanofluid of fixed temperature Tc penetrates into the domain from the right open border. The nanofluid circulation is Newtonian, incompressible, and laminar. The uniform magnetic field of strength B at the tilted angle of γ is applied. The finite volume technique is used to work out the non-linear equations of liquid motion and energy transport. For Rayleigh number (Ra=1e+7), numerical simulations were executed for varying the solid volume fractions of the nanofluid (ϕ = 0.01–0.04), the aspect ratios of a solid body (As = 0.25–4), the Hartmann number (Ha = 0–100), the magnetic influence inclination angle (γ = 0–π/2) and the non-dimensional temperature drop (Ω = 0.001–0.1) on the liquid motion, heat transference and entropy production.FindingsNumerical outcomes are demonstrated by using isolines of temperature and stream function, profiles of mean Nusselt number and entropy generations. The results indicate that the entropy generation rate and mean Nu can be decreased with an increase in Ha. The inner solid block of As = 0.25 reflects the maximum heat transfer rate in comparison with other considered blocks. The addition of nano-sized particles results in a growth of energy transport and mean entropy generations.Originality/valueAn efficient computational technique has been developed to solve natural convection problem for an open chamber. The originality of this research is to scrutinize the convective transport and entropy production in an open domain with inner body. The outcomes would benefit scientists and engineers to become familiar with the investigation of convective energy transference and entropy generation in open chambers with inner bodies, and the way to predict the energy transference strength in the advanced engineering systems.

A Brief Review on Thermal Behaviour of PANI as Additive in Heat Transfer Fluid

Since a decade ago, investigation on nanofluids has grown significantly owing to its enhanced thermal properties compared to conventional heat transfer fluids. This engineered nanofluid has been widely used in the thermal engineering system to improve their energy consumption by improving the thermal efficiency of the system. The addition of nano-size particles as additives dispersed in the base fluids proved to significantly either improve or diminish the behaviour of the base fluids. The behaviour of the base fluid highly depends on the properties of the additives material, such as morphology, size, and volume fraction. Among the variety of nanoparticles studied, the conducting polymers have been subject of high interest due to its high environmental stability, good electrical conductivity, antimicrobial, anti-corrosion property and significantly cheap compared to other nanoparticles. As such, the main objective of the present review is to provide an overview of the work performed on thermal properties performance of conducting polymers based nanofluids.

Superior corrosion and wear resistance of pulse plated Ni–W–B/SiC composite coatings

In the present work, Ni–W–B/SiC composite coatings have been produced under pulse current condition which in through the influence of SiC nanoparticles amount in the coatings were investigated (by changing the concentration of SiC in the plating bath from 0 to 12 g/l) were examined. It was found that initial inclusion of SiC nanoparticles into the plating bath (4 g/l SiC) leads to presence of SiC nanoparticles in the coatings. However, subsequent addition of SiC nanoparticles up to the 8 g/l results in lower SiC amounts in the deposits due to the agglomeration of the nanoparticles. The corrosion resistant of the coating increases from 20.406 to 33.360 kΩ cm2 by adding 4 g/l SiC to the plating electrolyte and wear weight loss of the coating is decreases from 0.410 to 0.303 mg/cm2 respectively, which reveals enhanced electrochemical and tribological behavior. It seems that dense deposit with higher amounts and uniform distribution of SiC particles in the above composite coating is the main reason for improving corrosion and wear resistance.

Preparation of bimetallic nano-composite by dissimilar friction stir welding of copper to aluminum alloy

Butt friction stir welding between pure copper and AA5754 alloy was carried out. Reinforcing SiC nano- particles were utilized in friction stir welded (FSW) joints to decline the harmful effects of intermetallic compounds. Tensile tests, micro-hardness experiments, scanning electron microscopy and X-ray diffraction analysis were applied to studying the properties of welded joints. The joints with a travel speed of 50 mm/min and a rotation speed of 1000 r/min showed the best results. The presence of nano-sized SiC particles reduced the grain size of aluminum and copper in the stir zone (SZ) from 38.3 and 12.4 μm to 12.9 and 5.1 μm, respectively. The tensile strength of the joint in the presence of reinforcing SiC nano-particles was ~240 MPa, which is ∼90% of that for the aluminum base. Furthermore, the highest microhardness of the weld zone was significantly increased from HV 160 to HV 320 upon the addition of SiC nano-particles. The results also showed that raising the heat generation in FSW joints increased the amount of Al4Cu9 and Al2Cu intermetallic compounds.

Computational assessment of thermo-hydraulic performance of [formula omitted]-water nanofluid in hexagonal rod-bundles subchannel

This study investigated alumina nanofluid's thermo-hydraulic performance as a coolant in the subchannel geometry of a hexagonal rod-bundle reactor core using the computational fluid dynamics (CFD) tools. This study analyzed the critical thermo-hydraulic performance-the heat transfer enhancement for an permissible increased pressure drop limit while considering the variation in the volume of nanoparticles concentrations, consistent with the previous related studies. The simulation model was developed for single-phase, forced, and turbulent flow conditions with a homogeneous mixture of species. The simulation results compared with the relevant standard correlations for the inlet Reynold number range of 20,000 to 80,000. Our study exhibited that heat transfer can be improved significantly with the addition of nano-size particles. This rise in heat transfer decreased the fuel clad surface temperature, improving the reactor fuel-clad temperature safety margin. However, the pressure drop also increased considerably, which needed to be within the permissible limit. Therefore, a trade-off between the heat transfer enhancement and drawback of the increased pressure drop within the reactor design limit is recommended.

Graphene nanoplatelets as additives to MQL for improving tool life in machining Inconel 718 alloy

Inconel 718 is widely used in the aerospace sector thanks to its excellent mechanical properties and corrosion resistance. However, these unique characteristics coupled with its low thermal conductivity make Inconel 718 a difficult-to-cut material. To limit the temperature rise within the cutting zone, flooding is conventionally used leading to health risk for operators and environmental impact. The addition of nano-sized particles to the biodegradable oil in Minimum Quantity Lubrication (MQL) to create a mixture called NanoFluid (NF) represents an alternative to flooding. In the present study, Graphene NanoPlatelets (GNPs) were chosen as additives to create NF. Turning trials were performed by spraying NF at different concentrations and flow rates. First, the NF characteristics were studied in terms of viscosity, specific heat capacity, stability and coefficient of friction. Then, the tool wear mechanisms were identified and quantified, and the machined surface finish analyzed at varying cutting length. Finally, on the basis of the experimental findings and the environmental impact of NF, the optimum combination of graphene concentration and flow rate was provided in order to simultaneously accomplish tool life increase and formation of smoother surfaces.

BN–SiC ensembles to form tribofilm with excellent shielding effects in PEEK- stainless steel contacts for artificial joint

Developing more reliable joint prostheses is crucial for minimizing impact of end-stage arthritis. In this work, SiC-BN hybrid nanoparticles were compounded into PEEK and their roles in tribocorrosion behaviors of PEEK sliding against a 316L steel in simulated body fluid were explored. Our results manifest that the addition of SiC and BN nanoparticles enhances synergistically tribological performance of the friction pairs. Tribofilm growth and tribo-chemistry at the friction interface were thoroughly investigated. It is demonstrated that hydrolysis products of SiC and easy-slippery characteristic of BN released onto the interface endow the tribofilm with shielding and boundary lubrication effects. Hence, when sliding takes place with the PEEK composite filled with SiC/BN hybrids, the friction pairs exhibit high tribological and anti-corrosion performance.