Nano-sized Ceramic Particles Research Articles

Tribological performance of ZrO2 nanoparticles as friction and wear reduction additives in aviation lubricant

Abstract High-performance aircraft engines require superior aviation oils to enhance their lubricating performance and prolong service life. Addition of nano-sized ceramic particles has been considered as a useful way to improve the tribological performance of base fluids. Up to now, few previous studies focused on the tribological properties of ZrO2 nanoparticles in aviation oil. The current study dispersed ZrO2 nanoparticles into PAO20 aviation base oil as lubricant additives. A dual-step method comprised of physical blending and ultrasonic dispersing was applied in the preparation of ZrO2 nanofluids. Oleic acid was utilized as surfactant to enhance the stability of ZrO2 nanofluids. Ball-on-plate reciprocating sliding wear tests were conducted to obtain the coefficient of friction and wear volumes. It was found that the PAO20 base oil produced the highest coefficient of friction of 0.278 and wear volumes of 2.305╳10-2 mm3. 5wt% ZrO2 nanofluids with 5wt% oleic acid showed the best lubricating performance. The coefficient of friction was reduced by 31.29%, and wear volume was reduced by 42.95%. In the examination of wear tracks, a physically embedded tribo-layer of ZrO2 nanoparticles and an oleic acid tribo-film with low shearing resistance were formed, which lowered the friction, and protected the mating surfaces against abrasive and adhesive wear. The results obtained in this study have applicable values in the development of high-performance aviation lubricants.

Insight into the interface effect and PTC effect on the temperature-adaptive electrical conductivity of epoxy composite

Doping functional fillers into the polymeric matrix is an effective strategy to improve the electrical, thermal, and other performance of insulating materials. It is imperative to understand the influence of fillers on the charge carrier behavior to achieve better regulation effectiveness. In this work, micrometer-sized and nano-sized ceramic particles with positive temperature coefficient (PTC) electrical resistivity are employed to prepare the epoxy composites, whose electrical conductivity under different temperature and electric field, space charge characteristics, permittivity, and electric field distribution are studied. It is found that the doping of a PTC filler shifts the electrical conduction from bulk-controlled to electrode-limited, determining the quantity of charge carriers within epoxy composites. While the interface effect mainly affects the transport process of charge carriers, it would fail to dominate the electrical conduction since the abundant charge carrier introduced by the semiconductive functional filler. Combined with the reinforced interface effect, the electrical conductivity–temperature characteristic of the epoxy nanocomposite is optimized, leading to the reduction in the maximum electric field within electrical equipment insulation by 55%. These findings emphasize the synergistic regulation of charge carrier amount and transport, which contributes to the precision design of polymeric composites doped with functional fillers.

Sliding tribological properties of nano-sized ceramic particles as oil-based lubricant additives

The present research investigated the lubricating performance of ZnO, SiO2, and WS2 nanoparticles as oil additives applied on steel frictional pairs. The study consisted of two stages. In first stage, the lubricating properties of nanofluids were examined using the various nanoparticle concentrations. It was obtained that the 3wt% ZnO, 5wt% SiO2, and 3wt% WS2 nanofluids showed the best performance. In second stage, an orthogonal test matrix was designed to understand the influences of load, sliding frequency and surface roughness on the lubricating behavior of the nanofluids. It was found that the frequency and load had the most significant effects on the friction reduction and anti-wear properties of ZnO, SiO2, and WS2 nanofluids. By using scanning electron microscopy and energy dispersive X-ray spectroscopy for potential mechanisms. It was found that the nanoparticles could be physically embedded, and adhered to the worn areas to form tribo-films resulting in improved tribological performance.

A Polymer-Based Metallurgical Route to Produce Aluminum Metal-Matrix Composite with High Strength and Ductility.

In this investigation, an attempt was made to develop a new high-strength and high-ductility aluminum metal-matrix composite. It was achieved by incorporating ceramic reinforcement into the metal which was formed in situ from a polymer by pyrolysis. A crosslinked PMHS polymer was introduced into commercially pure aluminum via friction stir processing (FSP). The distributed micro- and nano-sized polymer was then converted into ceramic particles by heating at 500 °C for 10 h and processed again via FSP. The produced composite showed a 2.5-fold increase in yield strength (to 119 MPa from 48 MPa) and 3.5-fold increase in tensile strength (to 286 MPa from 82 MPa) with respect to the base metal. The ductility was marginally reduced from 40% to 30%. The increase in strength is attributed to the grain refinement and the larger ceramic particles. High-temperature grain stability was obtained, with minimal loss to mechanical properties, up to 500 °C due to the Zenner pinning effect of the nano-sized ceramic particles at the grain boundaries. Fractures took place throughout the matrix up to 300 °C. Above 300 °C, the interfacial bonding between the particle and matrix became weak, and fractures took place at the particle-matrix interface.

Synergetic effects of cryo-FSP on microstructural, mechanical and corrosion behavior of stir cast AA5083-2 wt% SiC nanocomposite

In recent past, a significant research attention has been given to the study of nanosize ceramic particles reinforced aluminium alloy composites due to its excellent mechanical and surface properties compared to unreinforced counterpart. Hence, the major aim of the present study is to investigate the effects of cryocooling friction stir processing (cryo-FSP) on microstructural evolution, and its effects on mechanical properties & corrosion behavior of a stir-cast 2 wt% nanosize SiC (n-SiC) particles reinforced AA5083 nanocomposite in comparison to the room temperature (RT) FSPed and as cast counterparts. The cryo-FSP was performed successfully using optimized process parameters of 1400 rpm and 40 mm/min traverse speed using a specially designed cryo-FSP setup extracting deformation heat efficiently by a flowing mixture of LN2 and methanol (−30 °C). Evolution of a finer equiaxed grain structure (∼2 μm) with a homogeneous distribution of n-SiC particles and precipitate phases is confirmed (through SEM-EBSD and STEM/TEM analysis) in the cryo-FSPed composite compared to RT-FSPed sample (∼4 μm). The cryo-FSPed sample exhibited a superior yield strength (i.e., YS = 230 ± 3 MPa) compared to the RT-FSPed sample (i.e., YS = 197 ± 4 MPa) with a reasonably good ductility for both (i.e., 14 %). The improved YS is attributed mainly to the grain boundary strengthening due to extra grain refinement induced by cryo-FSP and dispersion strengthening via second phase particles. Different strengthening mechanisms' analyses established a good correlation between the theoretical YS and experimentally obtained tensile YS. Fractography analysis corroborated well with the tensile properties of the corresponding samples. Compared to the interdendritic cast structure, both the FSPed samples exhibited a superior corrosion resistance due to an improved surface characteristic developed in the dynamically recrystallized matrix with uniform dispersion of second phase particles. However, due to more grain boundary active phenomenon and higher misorientation angles, a bit higher corrosion rate could be observed in the fine-grained cryo-FSPed sample compared to the RT-FSPed composite.

Mechanical properties and strengthening mechanism of the nano-sized m-ZrO2 ceramic particle reinforced NbMoTaW refractory high-entropy alloy

Body-centered cubic (BCC) refractory high-entropy alloys (RHEAs) possess the typical advantage of high strength. However, RHEAs often exhibit apparent brittleness at room temperature, which remains great challenges for their engineering applications. In this study, NbMoTaW with 0 and 1 wt% m-ZrO2 nano-sized ceramic particles RHEAs have been successfully fabricated by ball milling and spark plasma sintering (SPS). The effect of m-ZrO2 ceramic particles on the microstructures and mechanical properties of NbMoTaW RHEAs was investigated. Results show that the matrix of alloys was characterized by single-phase BCC. Microstructural analysis shows that the grains in the single-phase BCC alloy have been refined by 39.0% through introduction of oxide nano-ceramic particles. The m-ZrO2 ceramic addition could effectively enhance both the hardness and strength of the NbMoTaW RHEA, accompanied by a slight decrease in plasticity. Compared with the vacuum arc-melting (VAM) method, the sintered NbMoTaW-1ZrO2 RHEA shows a significant increase in comprehensive compressive properties, especially the ductility. The yield strength, ultimate compressive strength and fracture strain of sintered NbMoTaW-1ZrO2 RHEA are 1775 MPa, 2118 MPa and 12.4%, respectively, surprisingly increased by 67.8%, 74.9% and 376.9%. A quantitative yield strength model correlating m-ZrO2 ceramic particle size, volume fraction and NbMoTaW-1ZrO2 grain size was built. The addition of fine m-ZrO2 ceramic resulted in Orowan strengthening and fine grains, thereby increasing yield strength of alloy. The superior combination of mechanical properties of the NbMoTaW-1ZrO2 RHEA could promote it to be a promising alloy in engineering applications.

Understanding the effect of particle reinforcement on friction stir weldment: A review

Friction stir welding is a solid-state environment-friendly joining process with many advantages over all fusion welding processes. Many variants in friction stir welding are used for uplifting the process to its maximum possible extent. One such variant is particle reinforcement in the weldment, which is used for improving the mechanical properties by enhancing the metallurgical aspects in the weld region. Generally, micro- and nano-sized ceramic particles are used for reinforcing, which have a much higher melting point than the materials to be joined. From the literature studies, particle size plays a prominent role in attaining better mechanical properties in reinforcing techniques. In addition, an increase in particle size decreases the corresponding mechanical property. Higher heat input conditions like higher tool rotational speed and low welding speed are preferred as they better mix reinforced particles with the matrix material in the weld zone. However, the higher input conditions in the regular friction stir welding process coarsen the grains, thereby deteriorating the mechanical properties of the joint. Increasing the number of passes and switching the direction between the passes leads to uniform distribution of particles and enhance the mechanical properties. This review article's main aim is to understand better reinforcement particles in the weld line of a friction stir welding process. Also, the author emphasizes reinforcing the combination of nano and microparticles to reduce the cost of reinforcement without compromising the mechanical properties. The work mentioned above is missing in the open literature.

Experimental Investigation of Tribological Properties of Two Fully Formulated Engine Oils with Additional Nanoscale Spherical Zirconia Particles

Decreasing harmful emissions of vehicle engines is becoming more and more challenging due to stricter standards. A possible solution is to improve the tribological attributes of lubricants, which can be achieved through the application of appropriate additives. According to preliminary studies conducted by the authors, ZrO2 (zirconium-dioxide) nano-sized ceramic particles as lubricant additives have overwhelmingly positive tribological attributes in the presence of non-metallic superficial materials. Additive concentration, as well as cross-effects with other additives were investigated in order to determine a formulation resulting in optimal tribological attributes. In this paper, the experimental investigation of ZrO2 nano-ceramic powder as a lubricant additive is presented. The tribological performance of individually samples were experimentally investigated on a ball-on-disc translational tribometer. The experiments revealed an optimal additive content of 0.3 wt%. Increasing the quantity of additives further ruined friction and wear properties of the examined tribological system.

Synergistic optimization in microstructure and mechanical properties of low carbon steel via trace amount of nano-sized TiC-TiB2

The current research studied the microstructure and mechanical properties of low carbon steels reinforced by a trace amount of TiC-TiB 2 nanoparticles. An innovative method was proposed to introduce the nanoparticles into molten iron through the use of an aluminum master alloy. It was found that the addition of nanoparticles refined the grains and lamellar structures in pearlite of low carbon steels. During the liquid-solid phase transformation, the amount of widmanstatten structures containing acicular ferrite decreased after adding the nanoparticles. For mechanical properties, the simultaneous enhancement of hardness, tensile properties and impact toughness of low carbon steels was achieved. According to the edge-to-edge matching model, it was found that the nanoparticles could be utilized as heterogeneous cores to facilitate the nucleation of austenite and ferrite. A higher nucleation rate resulted in finer microstructure under as-cast and annealed conditions. Moreover, the enhanced yield strength and tensile strength were attributed to the inhibition of migration of dislocations due to more grain boundaries and the nanoparticles. The enhanced ductility and toughness were associated with the fine microstructure and scattering behavior of cracks by the nanoparticles. These results can be used as references in the development of high-performance steels by using the nano-sized ceramic particles. • Nanoparticles-reinforced low carbon steels were prepared by using a TiC-TiB 2 /Al master alloy. • The as-cast and annealed microstructures were refined by adding TiC-TiB 2 nanoparticles. • The mechanical properties were simultaneously enhanced by adding TiC-TiB 2 nanoparticles. • An E2EM model indicated that the nanoparticles could be utilized as heterogenous cores.

Digital light processing (DLP) of nano biphasic calcium phosphate bioceramic for making bone tissue engineering scaffolds

Nano-sized ceramic particles are beneficial for the properties of 3D printed structures via digital light processing (DLP). However, achieving optimal conditions for the preparation and processing of ceramic nanoparticle-based slurry is a significant challenge. In this work, a stable and well dispersed slurry with nano-sized biphasic calcium phosphate (BCP) powders was developed and porous BCP bioceramic scaffolds with good bioactivity were accurately fabricated via the DLP additive manufacturing technology. Effects of dispersant, photoinitiator and solid loading on rheological properties and curing abilities of BCP slurries were systematically studied. The slurry having 65 wt % of nano-sized BCP powders showed a relatively low viscosity of 400 mPa s at the 50 s−1 shear rate. It was found that the optimal photoinitiator concentration was tightly associated with the energy dosage in DLP. Furthermore, the effects of sintering temperature (1100 °C, 1200 °C and 1300 °C) on the surface morphology, shrinkage, phase constitution, hardness, compressive properties, and in vitro biological performance of DLP-formed bioceramics were comprehensively investigated. The results showed that DLP-formed BCP ceramics sintered at 1300 °C had the best mechanical properties, in vitro cytocompatibility, and homogeneous bone-like apatite formation ability. Finally, DLP-formed 3D scaffolds with different pore sizes ranging from 300 μm to 1 mm were successfully fabricated, which exhibited high fidelity and accuracy. The current study has demonstrated the great potential of using DLP technology to construct functional complex BCP bioceramic scaffolds for bone tissue regeneration.

ИЗГОТОВЛЕНИЕ МЕТАЛЛОМАТРИЧНЫХ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ С ПРИМЕНЕНИЕМ АДДИТИВНЫХ ТЕХНОЛОГИЙ (обзор)

A review of scientific and technical literature in the field of obtaining metal-matrix composite materials (MMCM) reinforced with ceramic particles using additive technologies is presented. The structure, basic physical and mechanical properties and morphology of MMCM are briefly described. The structure and properties of MMCM reinforced with micro- and nano-sized ceramic particles are briefly described. The use of additive technologies for the manufacture of MMKM will make it possible to manufacture parts of a more complex shape, providing high adhesion between powder layers.

Nano/micro implant debris affect osteogenesis by chondrocytes: Comparison between ceramic and UHMWPE from hip walking simulator.

A new generation of ceramic on ceramic (BIOLOX ®delta) bearings has emerged more than 10 years ago proving a high resistance to wear and good clinical results. However, biological reactions to wear debris, particularly the nanoparticles, need to be evaluated. The first originality of this study is to start from real wear particles obtained by the hip walking simulator (CERsim). These particles were compared with particles obtained by usual methods to assess the biocompatibility of materials: press machine (CERpress). Two ranges of ceramic particles were thus observed: ceramic particles with micron (intergranular fractures) and nano sizes (intragranular fractures), and characterized compared to ultra-high molecular weight polyethylene (UHMWPE). The second originality of this work is to assess the cellular reaction using the primary joint chondrocyte cultures simulating the osteogenesis process and not the cell lines, which are used to simulate the biological reaction of osteolysis. The first results showed a significant difference in cell viability between the cells in contact with particles from the walking simulator and those obtained with the press machine. On the other hand, it was found that the way of extraction of the particles from the lubricant could significantly affect the biological reaction. More interestingly, nano-sized ceramic particles showed a significant impact on the secretion of functional inflammatory mediators, agreeing with recent results in vivo. These novel methods of characterizing the osteogenic impact of UHMWPE and ceramic wear debris can complement the conventional expertise method focusing previously on the osteolysis aspect.

Tribološka svojstva nanostrukturnih keramičkih čestica ZrO2 u automobilskim mazivima

The demand for decreasing CO2-emission and harmful material content of the exhaust gas of passenger cars requires the improvement of the entire powertrain including the applied lubricants. One of the possible future engines lubricant can be the nano-sized ceramic particles, which can provide positive tribological properties also in the presence of nonmetallic surface materials. This paper presents the experimental investigation of ZrO2 nanoceramic powder as a lubricant additive. The tribological performance of the lubricant samples was experimentally investigated on a ball-on-disc translation tribometer. An optimum concentration was found at 0.4 wt%, where the wear scar diameter on the ball specimen was reduced by more than 40% compared to the reference sample. The SEM-analysis confirmed the mending mechanism theory: nanoparticles were revealed to aggregate between the asperities resulting in a significantly smoother contact surface.

Investigation of the tribological properties of nano-scaled ZrO2 and CuO additive in automotive lubricants

To improve the fuel efficiency and the lifetime of the internal combustion engines, the lubricants and their additives have to be developed further. One of the possible future engines lubricants can be the nano-sized ceramic particles, which can provide positive tribological properties also in the presence of non-metallic surface materials. This paper presents the results of investigations with the help of ZrO2 and CuO nano-sized ceramic particles. To define the tribological properties of these additives, lubricant samples with different additive-concentrations were prepared and tribologically analysed. The frictional losses of these lubricant samples were analysed by a ball-on-disk sliding friction machine. The worn surface on the test specimens was analysed by different high-resolution microscopes. To define the functional mechanisms of the nano-additives, the worn surfaces were investigated by high resolution scanning electron microscopes. The ZrO2 additive has experimentally shown an excellent wear reduction property (over 40% wear reduction compared with the neat Group 3 base oil) at the optimum mixing concentration of 0.4wt%. Both frictional and wear reduction properties could be determined at the application of CuO additive (15-15% friction coefficient and wear scar diameter reduction) at its optimum concentration (0.5wt%). A copper-yellow layer can be seen on the worn surface of the disc specimens with CuO, which indicates the mechanism of chemical transformation to elementary copper from the cupric-oxide nanoparticle and this elementary copper can be melted on the surface, because of the applied high temperature and high loads during the experiments.

Fatigue properties of value-added composite from Al-Si-Mg/palm kernel shell ash nanoparticles

The fatigue properties of AMCs are affected by low ductility, poor toughness, and resistant to crack growth which is attributed to the reinforcement particles, sizes, and shapes, because the crack growth rate behavior of the composite displays a markedly higher sensitivity to the applied stress intensity (K) than observed in most metals. The use of nano-sized ceramic particles has been reported to strengthen the metal matrix, while maintaining good ductility, high temperature creep resistance, and better fatigue. Based on this background, fatigue properties of Al-Si-Mg/palm kernel shell ash nanoparticles (PKSAnp) was investigated. Sol-gel method was used in the production of the PKSAnp; 4 wt% of PKSAnp was added to Al-7%Si-0.3%Mg alloy to produce A356/4 wt% PKSAnp composites; fatigue properties were determined as per ASTM E466; microstructure of the composite was determined using a scanning electronic microscope; ANSYS bench work software was used determined the factor of safety and fatigue life. The presence of PKSAnp in the alloy has great influences that alter the number of cycles obtained for the composite even at higher temperature. The presence of PKSAnp shifted the curve to a higher number of cycle before failure. The result shows that failure of the alloy will occur before the design life is reached since the minimum value obtained for the alloy is less than one.

Nano-size carbide-reinforced Ni matrix composite prepared by selective laser melting

Thermally stable nano-size ceramic particles are the preferred reinforcements for superalloys as they improve the alloys' microstructural stability and high-temperature properties. In this work, very dense and crack-free carbide-reinforced GTD222 (nickel-based superalloy) composites were prepared via selective laser melting (SLM). The distribution of TiC nanoparticles presents a three-dimensional (3D) network structure in the SLMed TiC/GTD222 composite. Mechanical testing revealed that the SLMed TiC/GTD222 composite has superior strength (UTS = 1320 MPa, YS = 1100 MPa) compared to the SLMed GTD222 superalloy. The GTD22 alloy reinforced with carbide nanoparticles’ distinctive microstructure and its excellent mechanical properties for is discussed.

Effects of nano-sized ceramic particles on the coefficients of thermal expansion of short SiC fiber-aluminum hybrid composites

Coefficients of thermal expansion (CTE) for short SiC fiber-reinforced aluminum matrix hybrid composites (AMHCs) containing nano-sized SiC particles are predicted through a novel multi-step micromechanics approach. The thermo-mechanical properties of aluminum matrix filled with SiC nanoparticles are extracted utilizing an analytical micromechanics model as a first step. These effective properties are then used in the Mori-Tanaka method to obtain the effective CTEs of AMHCs. The modeling of nanoparticle agglomeration often formed in real engineering situations, is accomplished using a nested method. The predictions of the developed micromechanical model are compared to experimental measurements available in the literature, and an acceptable agreement is observed between them. The effects of the volume fraction, diameter and agglomerated degree of SiC nanoparticles, and also the volume fraction and aspect ratio of SiC short fibers on the AMHC CTEs are investigated. In addition to randomly oriented fiber-reinforced AMHCs, modeling of the effective CTEs of aligned short fiber-reinforced AMHCs is performed. The results reveal that addition of nano-sized SiC particles reduces the CTE of short SiC-fiber-reinforced AMHCs. The decrease of particle size and increase of fiber aspect ratio also assist in improving the overall thermo-elastic properties of AMHCs. However, the presence of the ceramic nanoparticle agglomeration leads to increase the AMHC CTEs. According to the micromechanical analysis, it is found that the alignment of short fibers is an efficient method to reduce the AMHC CTEs.

Molecular dynamics simulation and experimental verification for bonding formation of solid-state TiO2 nano-particles induced by high velocity collision

Collision processes of solid-state nano-sized ceramic particles were investigated by molecular dynamics (MD) simulation in order to clarify their bonding mechanisms. Effect of particle temperature on particle bonding formation was examined, and collision behavior of nano-sized TiO2 particle was discussed in terms of particle deformations. Microstructures and bonding qualities of bonded nano-sized TiO2 particles induced by high velocity collision were examined by high resolution transmission electron microscope (HR-TEM) to verify the MD results. Simulation results demonstrate that the bonding formation of nano-sized TiO2 particles can be attributed to the atomic displacement and lattice distortion in localized impact region of particle boundaries. TEM microstructure results prove simulation results and indicate effective chemical bonding formations between nano-particles at low temperature by high velocity collision. Quantitative results show that the high temperature is beneficial to the particle bonding formation. The asperity around nano-sized ceramic particles surface contributes to the displacement and lattice distortion in localized impact region under the high impact compressive pressure. The fact demonstrates a new mechanism of nano-scale ceramic particle bonding formation induced by the localized atomic displacement. The study present opens up a promising prospect of fabricating functional equipment with nano-scale ceramic particles with high velocity collision at ambient temperature.

Nanocomposite quasi-solid-state electrolyte for high-safety lithium batteries

Rechargeable lithium batteries are attractive power sources for electronic devices and are being aggressively developed for vehicular use. Nevertheless, problems with their safety and reliability must be solved for the large-scale use of lithium batteries in transportation and grid-storage applications. In this study, a unique hybrid solid-state electrolyte composed of an ionic liquid electrolyte (LiTFSI/Pyr14TFSI) and BaTiO3 nanosize ceramic particles was prepared without a polymer. The electrolyte exhibited high thermal stability, a wide electrochemical window, good ionic conductivity of 1.3 × 10−3 S·cm−1 at 30 °C, and a remarkably high lithium-ion transference number of 0.35. The solid-state LiFePO4 cell exhibited the best electrochemical properties among the reported solid-state batteries, along with a reasonable rate capability. Li/LiCoO2 cells prepared using this nanocomposite solid electrolyte exhibited high performance at both room temperature and a high temperature, confirming their potential as lithium batteries with enhanced safety and a wide range of operating temperatures.

Engulfment of ceramic particles by fibroblasts does not alter cell behavior

Despite many studies, the impact of ceramic particles on cell behavior remains unclear. The aim of the present study was to investigate the effects of nano-sized ceramic particles on fibroblastic cells. Fibroblasts (dermal fibroblasts freshly isolated from skin samples and WI26 fibroblastic cells) were cultured in a monolayer in the presence of alumina or cerium–zirconia particles (≈50 nm diameter) at two concentrations (100 or 500 μg ml−1). Fluorescent alumina particles were also used. The following properties were analyzed: cell morphology, cytoplasmic ceramic incorporation (using confocal and transmission electron microscopy) and migration (using a silicon insert). Sedimentation field-flow fractionation (SdFFF) was also used to evaluate the rate of incorporation of ceramic particles into the cells. Finally, after treatment with various concentrations of ceramic particles, fibroblasts were also included in a collagen type I lattice constituting a dermal equivalent (DE), and the collagen lattice retraction and cell proliferation were evaluated. In monolayer conditions, the presence of both alumina and cerium–zirconia ceramic particles did not cause any deleterious effects on cultured cells (dermal fibroblast and WI26 cells) and cell fate was not affected in any way by the presence of ceramic particles in the cytoplasm. Confocal (using fluorescent alumina particles) and electron microscopy (using both alumina and cerium–zirconia particles) showed that ceramic particles were internalized in the WI26 cells. Using fluorescent membrane labeling and fluorescent alumina particles, a membrane was observed around the particle-containing vesicles present in the cytoplasm. Electron microscopy on WI26 cells showed the presence of a classical bilayer membrane around the ceramic particles. Interestingly, SdFFF confirmed that some dermal fibroblasts contained many alumina ceramic particles while others contained very few; in WI26 cells, the uptake of alumina ceramic was more homogeneous. In DE, collagen lattice retraction and cell proliferation were unchanged when WI26 fibroblastic cells contained alumina or cerium–zirconia ceramic particles. Our data suggest that ceramic particles are internalized in the cells by endocytosis. The presence of ceramic particles in the cytoplasm has no affect on cell behavior, confirming the excellent biocompatibility of this material and anticipating a minimal harmful effect of potential wear debris.