Adhesive Wear Mechanism Research Articles

Taguchi analysis for sliding wear characteristics of carbon nanotube-flyash reinforced aluminium nanocomposites

Dry sliding wear characteristics of aluminium nano-composites reinforced with different wt. % of multiwall carbon nanotubes (0.25, 0.5, 0.75 wt. %) and fly ash (4, 8, 16 wt. %) produced by powder metallurgy were investigated. ANOVA and Taguchi methods of design of experiment technique were successfully used to determine the predominant factors and optimisation of the testing parameters on wear. MWCNT (wt. %) and FA (wt. %) was found to be the predominant parameter affecting wear loss with percentage contribution of 43.71% and 30.78%. The results of Taguchi indicate the optimized values of wear parameters were 0.25wt. % MWCNT, 8 wt. % FA, 2 h ball milling, 6 h sintering, 10 N applied load, 200 rpm sliding speed and 500 m sliding distance. The microstructure of composites exhibited well dispersion of the reinforcements in the aluminium matrix. The study of worn surfaces revealed minor grooves and delamination wear due to abrasive and adhesive wear mechanisms.

Insight on the Mechanical and Tribological Characteristics of Ball-on-Socket Artificial Disc under Alternate Motion of Flexion Extension–Axial Rotation and Lateral Bending–Axial Rotation

Ball-on-socket articulation is the major structural type of artificial joints. The insight on the mechanical and bio-tribological characteristics of this structure is important for designing both the device itself and its wear assessment regime. Two kinds of ball-on-socket structures were studied including a simplified general model and a real artificial cervical disc. The bio-tribological behaviors were evaluated by in vitro wear simulation method using four kinds of pairs with different combinations of structure, frictional material and testing duration under alternate motion of FE-AR (flexion extension and axial rotation) and LB-AR (lateral bending and axial rotation). In order to analyze the formation mechanism of representative wear characteristics, the mechanical behaviors were also studied by finite element analysis method. The results indicated that there were similar mechanical and bio-tribological characteristics for these two structures after about 9 MC (Million Cycles) tests. Under the axial load, it revealed more serious wear severity in the edge region than that in the central region for both convex polymer component and concave metal component, which may be due to much higher values of equivalent stress and equivalent elastic strain in the edge region than that in the central region. Under FE (flexion extension) or LB (lateral bending) motion, it showed common wide and curved wear grooves with ring distribution in the edge region for both ball component and nucleus pulposus component, which may be attributed to the higher equivalent stress and equivalent elastic strain at the limit position. It just indicated several sliding scratches for TC4 (Ti6Al4V alloy) metal component with an abrasive wear mechanism, while it revealed plastic deformation, surface cracks, sliding scratches and wear grooves for XPE (crosslinking polyethylene) polymer component with a mix of abrasive wear and adhesive wear mechanism. Hence, there was a strong correlation between structural design and bio-tribological characteristics for ball-on-socket prostheses.

Relationship Between the Microstructural Evolution and Wear Behavior of U71Mn Rail Steel

During train operation in a wheel-rail system, the service lives of the wheel and rail materials are heavily influenced by microstructural evolution. This study investigated the relationship between microstructural evolution and the wear properties of U71Mn rail steel under conditions of dry sliding wear using an MRH-5A wear tester. The results demonstrated that tribological white etching layers (T-WELs), which comprise nanocrystalline α-Fe and fine carbide, are formed after a certain number of cycles. The T-WEL thickness increased with the number of cycles; however, more cycles caused T-WEL flaking, which resulted in a reduced T-WEL length. The high microhardness of T-WELs (approximately 950 HV) is mainly attributed to ferrite grain refinement and cementite dissolution. During initial wear, the existence of grinding marks on the surfaces of the samples indicated an obvious increase in the wear loss of the steel. The high microhardness of the T-WELs can enhance wear resistance; thus, as the number of cycles was increased, the wear loss of the steel was reduced. At this point, an adhesive wear mechanism acted on the rail steel. The formation of fatigue cracks at the interface between the T-WEL and the plastic deformation layer induces T-WEL flaking, which increases wear loss. Consequently, after 6000 cycles, wear loss increased as the wear mechanism changed to fatigue wear. It is confirmed that T-WEL flaking is the primary cause of wear failure in U7Mn rail steel.

Study on the Biotribological Properties of Ti6Al7Nb and Ultra High Density Molecular Weight Polyethylene at Different Lubricant Temperature

Higher frictional heat will be produced during the service process of artificial hip joint prosthesis in vivo than natural joint, which would cause the rise of the temperature of synovial fluid and the change of the wear resistance of prosthetic materials. In this work, the biotribological properties of ZrO2/Ti6Al7Nb and ZrO2/UHMWPE pairs at different lubricant temperatures were investigated. The results show that there is a strong correlation between the wettability and average friction coefficient of Ti6Al7Nb, while there is also a strong correlation between the wettability and mass loss of UHMWPE. The wear loss of Ti6Al7Nb and UHMWPE decreases gradually and the friction coefficient increases gradually as the lubricant temperature rises from 20 ℃ to 46 ℃, which is mainly affected by the precipitation process of protein. As a protective layer, it can reduce the wear rate, but as a third body, it can participate in the friction process and increase the friction coefficient. The characteristics of lubricant change greatly at 60 ℃, but the increase of temperature is not the only reason for the precipitation of synovial protein. The synergistic effect with the friction process results in a significant change on the wear mechanism of Ti6Al7Nb and UHMWPE under this condition. The wear mechanism of Ti6Al7Nb is mainly abrasive wear and adhesion wear at different lubricant temperature. With the increase of lubricant temperature, the proportion of adhesion wear mechanism becomes larger. Due to the low thermal deformation temperature and thermal conductivity, the wear mechanism of UHMWPE changed obviously at 60 ℃, and the wear morphology is mainly plastic deformation.

Tribological behavior of friction stir processed AA6061 aluminium alloy

Abstract In the age of light weight, aluminum alloys are used as one of the most predominant materials in automotive and aircraft industries. But their applications are being restricted where tribological (relative motion between parts) is major issue. Thus, coating metallic substrates i.e. aluminum alloys with ceramic powders is an effective solution in prolonging the component service life. The present investigation aims at changing the surface morphology by introducing carbide powders (180 µm) of boron, silicon and tungsten on to AA 6061 Al alloy (widely used in automobile components) using friction stir processing. Fabricated surface metal matrix composites (SMMCs) exhibited better wear resistance compared to the base metal. SMMC (127VHN) consisting B4C as reinforcement has shown superior wear resistance among other SMMCs made from WC and SiC respectively. From the SEM analysis, it is clearly observed that abrasion wear is the primary cause for less wear resistance in AA 6061 aluminium alloy while as adhesive wear mechanism is found to be predominant one in all other surface composites resulting in the increase of wear resistance. Thus, it is recommended to use B4C as reinforcing material for surface modification of AA6061 aluminum alloy when compared with other reinforcing materials of WC and SiC.

Coefficient of friction of dry sliding Al 6061-T6 alloy under different loading conditions

PurposeThis paper aims to focus on the effect of normal load, sliding speed and temperature on the coefficient of friction of Al 6061-T6 alloy under dry sliding conditions.Design/methodology/approachDry sliding experiments were conducted using rotary type pin on disk tribometer. Pins with 3 mm radius of contact and circular disks of 165 mm diameter were fabricated to simulate Hertzian contact configuration. Experiments were conducted by applying three different normal loads (1, 1.5 and 2 kg) and three different sliding speeds (1.25, 2 and 3 m/s) at different temperatures [room temperature (31 ± 1 °C), 60 °C, 100 °C and 150 °C].FindingsCoefficient of friction at end of the first cycle of sliding, stabilized stage, unsteady state and steady state are reported elaborately in this study. Adhesive and abrasive wear mechanisms were observed in the dry sliding of Al 6061- T6 alloy contacts from the microscopic analysis of worn contact surfaces. The coefficient of friction was more influenced by the increase in normal load than the increase in sliding speed and temperature.Practical implicationsThe results obtained from this study are significant for the design of aluminium-to-aluminium contacts in aerospace engineering and automobile engineering.Originality/valueThis study reveals the coefficient of friction of aluminium-to-aluminium (Al 6061-T6 alloy) contacts under cylinder on flat contact configuration.

Prediction of wear resistance model for magnesium metal composite by response surface methodology using central composite design

PurposeIn recent days, friction stir processing (FSP) has emerged as a pioneering approach for the manufacture of composites with enhanced mechanical and tribological properties. The present study aims to examine the impact of process parameters such as tool rotation speed and number of FSP pass on the AZ61A/TiC magnesium metal composite for responses such as hardness and wear resistance.Design/methodology/approachTo minimize number of experimental runs, design of experiment was configured according to the response surface methodology using central composite design. Analysis of variance has been conducted to develop mathematical and empirical model for studying relationship between tool rotation and number of pass for responses such as microhardness and wear resistance. Microhardness was checked on vickers microhardness testing machine, and tribological behavior were examined on pin-on-disc using tribotester. Wear morphology was analyzed via scanning electron microscopy.FindingsThe responses were predicted using validated mathematical model, and contour plots were generated to study the interaction and influence of process parameters. Wear observations suggest that for the base magnesium alloy adhesive wear mechanism was dominating and for the developed nanocomposites, abrasive wear mechanism is a prominent factor. It was also observed that both the selected parameters significantly influenced the responses.Originality/valueTo the best of the authors’ knowledge, no prior work has been conducted with this material and preparation of composites with TiC nanoparticles. Furthermore, no mathematical models have been developed to predict the response values.

Microstructure and Wear Behaviour of 17-4 Precipitation Hardening Stainless Steel with Various Ti Content

In this study, the wear behaviour of aged 17-4 PH SS (precipitation hardening stainless steel) that contains 0.5, 1, 1.5, and 2% of Ti was examined. The mixed elemental powders (in wt.%: 17 Cr, 4 Cu, 4 Ni, 1 Mn, 1 Si, 0.3 Nb, 0.07 C, and Fe remaining) were cold-pressed (800 MPa), and the pre-formed 17-4 PH SS green compacts were sintered at 1300°C for 60 min in a 0.1 Pa vacuum and at 4 °C/min heating rate and cooled down in furnace to room temperature. Alloys with different amounts of titanium were aged at 480°C for 1, 4, and 8 h. Scanning electron microscopy, X-ray diffraction analysis, and density and hardness measurements were employed to characterize the aged alloys. The pin-on-disc apparatus was used for wear testing. The wear testing was performed under the sliding speed of 0.8 m/sec, two various loads (of 30 and 45 N), and at five different sliding distances of 600, 1200, 1800, 2400, and 3000 m. Research results showed that in 17-4 PH SS, the weight loss and density decreases with a higher titanium content, while their hardness increase. Thus, a higher amount of Ti addition contributes to lower weight losses. The friction coefficient shows the highest value in the samples containing 0.5% Ti and the lowest in the alloy containing 2% Ti. M23C6 and M3C carbides are formed in the microstructure of the material, as expected. From the SEM images of worn surfaces, the adhesive and oxidative wear mechanisms were determined as dominant. Due to the choice of composition with the highest hardness and corresponding sintering conditions, the wear resistance of alloys can be increased significantly.

Tribological Behavior of AlCrSiN-Coated Tool Steel K340 Versus Popular Tool Steel Grades.

The tribological performance of metalwork steel tools is of vital importance in both cold and hot working processes. One solution for improving metal tool life is the application of coatings. This paper investigates the differences in quantitative wear behavior and wear mechanisms between AlCrSiN-coated and bare steel K340 and five reference tool steels: X155CrVMo12-1, X37CrMoV5-1, X40CrMoV5-1, 40CrMnMo7 and 90MnCrV8. The investigated tool steels were heat-treated, while K340 was subjected to thermochemical treatment and then coated with an AlCrSiN hard film (K340/AlCrSiN). The hardness, chemical composition, phase structure and microstructure of steels K340 and K340/AlCrSiN were examined. Tribological tests were conducted using the ball-on-disc tester in compliance with the ASTM G99 standard. The tests were performed under dry unidirectional sliding conditions, using an Al2O3 ball as a counterbody. The wear factor and coefficient of friction were estimated and analyzed with respect to hardness and alloying composition of the materials under study. Scanning electron microscopy (SEM) observations were made to identify the sliding wear mechanisms of the analyzed tool steels and physical vapor deposition (PVD)- coated K340 steel. In contrast to the harsh abrasive–adhesive wear mechanism observed for uncoated tool steels, the abrasive wear dominates in case of the AlCrSiN. The deposited thin film effectively prevents the K340 substrate from harsh wear severe degradation. Moreover, thanks to the deposited coating, the K340/AlCrSiN sample has a coefficient of friction (COF) of 0.529 and a wear factor of K = 5.68 × 10−7 m3 N−1 m−1, while the COF of the reference tool steels ranges from 0.70 to 0.89 and their wear factor ranges from 1.68 × 10−5 to 3.67 × 10−5 m3 N−1 m−1. The AlCrSiN deposition reduces the wear of the K340 steel and improves its sliding properties, which makes it a promising method for prolonging the service life of metalwork tools.

Preparation and Tribological Behaviors of Lubrication-Enhanced PEEK Composites

Poly-ether-ether ketone (PEEK) is a great potential thermoplastic in industry and medical treatment and health. In this work, PEEK/graphene oxide (GO) and PEEK/MoS2 composites were prepared by a novel hot isostatic pressing method. The addition of GO alters the tribological behaviors mechanism; fatigue wear mechanism is predominant to PEEK/GO composites. However, the combination of abrasive and adhesive wear mechanisms is observed for PEEK/MoS2 composites and PEEK. The reason for this is that the hardness and tensile strength of composites are increased with the appropriate addition of GO. The response time to stable friction state of PEEK/GO and PEEK/MoS2 composites is reduced in comparison with PEEK, which is conducive to shorten running-in time, reduce the energy consumption, and improve the tribological performances of composites. The addition of GO and MoS2 can effectively decrease the friction coefficient and wear rate, and the optimal content of GO and MoS2 was 0.7 wt.% and 15 wt.%, respectively. The results indicate that PEEK/GO and PEEK/MoS2 are impressive composites that possess super tribological properties.

Experimental investigation on post-processed NiCr thermal barrier coating and its sliding wear behaviour

NiCr metal is deposited on martensitic stainless steel using an atmospheric plasma spray method. To enrich the metallurgical properties of the NiCr metallic coating, a standard heat treatment process is adopted. From the investigation, it has been shown that the voids and porosity developed during the thermal spray have been controlled through heat treatment. Electron image analysis reveals that the coating has reduced porosity with strong and dense bonding strength. With reference to the surface hardness, the post-processed coating yields a maximum of 140 Hv compared with the coated (129 Hv) and base metal (115 Hv). Subsequently, the sliding wear behaviour of post-processed NiCr coating has a minimum wear of 25 μm for an applied load of 5 N and 57 μm for an applied load of 15 N. Owing to the high metallurgical bonding, the coating has sustained the heavy loads, and the wear formation is controlled. However, the base metal has an adhesive wear mechanism caused by the high frictional force on the sliding friction. Therefore, it is recommended that post-processed thermal barrier coatings possess good metallurgical bonding and withstand heavy load causing minimum wear.

Retrieval analysis of an explanted NuNec cervical disc: A case report

Retrieval analyses allow investigation of the efficacy of artificial implants to replace diseased or damaged natural joints. Implants are not always removed due to mechanical failure; a well-functioning implant may require removal due to causing pain. As an alternative treatment to fusion, total disc replacement is an evolving treatment. Recently, to eliminate the possible failure mechanisms observed in metal-on-polymer and metal-on-metal artificial discs, an all-polymer cervical artificial disc has been introduced. The NuNec cervical arthroplasty system is a self-mating, all-polymer design which utilizes a ball-in-socket configuration with each component made of polyether ether ketone. For the first time, a retrieval analysis of a NuNec cervical disc, which has been removed due to pain from a 54-year-old female patient, has been undertaken. The main reason associated with pain was the size of the implant which was found to be too big for the patient. The time in vivo of the implant was 2 years and at the time of removal, the implant was thought to be functioning well. The average surface roughness values of the socket and the ball of the explanted NuNec disc were measured as 0.067 ± 0.056 μm (Sa) and 0.037 ± 0.023 μm (Sa). Compared to an unused disc, the surface roughness significantly decreased (p = 0.00). The articulating surfaces of the explant had negative skewness and burnished appearances. Evidence for both abrasive and adhesive wear mechanisms was observed on the explant. The hydroxyapatite coatings at the backsides were completely lost.

Surface, Subsurface and Tribological Properties of Ti6Al4V Alloy Shot Peened under Different Parameters.

Ti6Al4V alloy was shot peened by using stainless-steel shots with different sizes (0.09–0.14 mm (S10) and 0.7–1.0 mm (S60)) for two durations (5 and 15 min) using a custom-designed peening system. The shot size was the main parameter modifying the roughness (0.74 µm for S10 vs. 2.27 µm for S60), whereas a higher peening time slightly increased roughness. Hardness improved up to approximately 35% by peening with large shots, while peening time was insignificant in hardness improvement. However, longer peening duration with large shots led to an unwanted formation of micro-cracks and delamination on the peened surfaces. After dry sliding wear tests, the mass loss of peened samples (S60 for 15 min) was 25% higher than that of un-peened samples, while the coefficient of friction decreased by 12%. Plastically deformed regions and micro-scratches were observed on the worn surfaces, which corresponds to mostly adhesive and abrasive wear mechanisms. The present study sheds light on how surface, subsurface and tribological properties of Ti6Al4V vary with shot peening and peening parameters, which paves the way for the understanding of the mechanical, surface, and tribological behavior of shot peened Ti6Al4V used in both aerospace and biomedical applications.

Optimization of wet sliding wear parameters of Titanium grade 2 and grade 5 bioimplant materials for orthopedic application using Taguchi method

In this research ball on disc wear tests have been carried out on Titanium grade 2 and Titanium grade 5 material using ASTM G-99 standard at room temperature in simulated body fluid. The tribological property such as the weight loss was studied by using the Taguchi design of experiments. The design of experiment was done using an L18 orthogonal array. An analysis of variance demonstrated that the individual contribution such as the applied normal load factor was 91.17% for weight loss, which means it is highest individual contribution as compared to other factors so it was concluded that weight loss is mainly influenced by the applied normal load. The analysis of the signal to noise ratio shows that the optimal weight loss was obtained with titanium grade 5 material at an applied normal load of 5 N with sliding velocity 0.05 m/s for sliding distance of 100 m. The results showed that weight loss increases with increasing the applied normal load and sliding velocity. The microstructure of all substrate materials was analyzed using a scanning electron microscope. Wear track study showed that adhesive dominant wear mechanism for both the grades.

Variational phase-field continuum model uncovers adhesive wear mechanisms in asperity junctions

Wear is well known for causing material loss in a sliding interface. Available macroscopic approaches are bound to empirical fitting parameters, which range several orders of magnitude. Major advances in tribology have recently been achieved via Molecular Dynamics, although its use is strongly limited by computational cost. Here, we propose a study of the physical processes that lead to wear at the scale of the surface roughness, where adhesive junctions are formed between the asperities on the surface of the materials. Using a brittle formulation of the variational phase-field approach to fracture, we demonstrate that the failure mechanisms of an adhesive junction can be linked to its geometry. By imposing specific couplings between the damage and the elastic energy, we further investigate the triggering processes underlying each failure mechanism. We show that a large debris formation is mostly triggered by tensile stresses while shear stresses lead to small or no particle formation. We also study groups of junctions and discuss how microcontact interactions can be favored in some geometries to form macro-particles. This leads us to propose a classification in terms of macroscopic wear rate. Although based on a continuum approach, our phase-field calculations are able to effectively capture the failure of adhesive junctions, as observed through discrete Molecular Dynamics simulations.

Role of tool rotational speed on the tribological characteristics of magnesium based AZ61A/TiC composite developed via friction stir processing route

Purpose: A new composite material was prepared and Different properties such as hardness and tribological behaviour of the fabricated metal matrix composite (MMC) was investigated and compared with the base AZ61A magnesium alloy. Design/methodology/approach: For the current research work, state-of-the-art technology, Friction stir processing (FSP) was performed to develop magnesium based AZ61A/TiC composite at optimized set of machine parameters. Findings: Increasing tool rotational speed ultimately leads in enhanced hardness, which further gives superior tribological properties as compared to base AZ61A alloy. Wear observations suggests a combination of abrasive and adhesive wear mechanism. Research limitations/implications: More microstructural and mechanical properties can be examined. Practical implications: The idea behind selecting AZ61A is mainly due to its increasing use in bicycle pedals and military equipment’s where at certain places it needs to encounter friction. In this current work, microhardness study and wear behaviour of AZ61A/TiC composite processed via FSP were examined. Originality/value: Paper is completely new and no work has been done till date considering this material and preparing composite with nanoparticles TiC.

Effect of Multiwalled Carbon Nanotubes on Elevated Temperature Tensile and Wear Behavior of Al2024 Matrix Composites Fabricated by Stir Casting and Hot Extrusion

In this study, aluminum alloy matrix composites reinforced with MWCNT particles by 0.5 wt.% were fabricated by a new developed technique, consisting of semi-powder metallurgy and stir casting processes. Then, hot extrusion process was applied to the composite materials. Phase analysis and microstructure investigations were performed for the as-cast and extruded samples. Hardness test was conducted, and tensile tests were applied at room, 150 and 250 °C. The tribological performances of unreinforced alloy and MWCNT-reinforced composite were examined at room, 150 and 250 °C as well. The results showed that hardness of base aluminum alloy was improved. The peaks belonging to the MWCNT were detected by x-ray diffraction (XRD) analysis. The incorporation of MWCNT presents strengthening effect on the mechanical properties at all test temperatures. The wear rate generally decreased with the addition of MWCNT for all test conditions. Extrusion process had a positive effect to enhance wear and hardness behavior. Abrasive, adhesive, oxidative and thermal wear mechanisms were observed by scanning electron microscope.

Comparative studies on corrosion and tribological performance of multilayer hard coatings grown on WC-Co hardmetals

Multilayer TiN/TiCN/TiCN/TiC/TiN and TiN/TiCN/TiCN/TiC/Al2O3 hard coatings with total thicknesses of 15.7 μm and 9.3 μm were deposited on WC-10Co substrates using a chemical vapor deposition system. Evaluation of surface, cross-section morphologies, chemical composition and phases of coatings were analyzed by field emission scanning electron microscopy (FESEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD) analyses respectively. Corrosion properties were evaluated in 3.5 wt% NaCl medium using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Tribological properties of fabricated multilayer hard coatings were evaluated using pin-on-disk tests. Results show that active dissolution of the WC-10Co occurred while the coated samples showed more anodic slopes as well as lower corrosion current densities. The corrosion current densities of 3.3 × 10−7 A/cm2 and 7.5 × 10−8 A/cm2 were obtained for the TiN/TiCN/TiCN/TiC/TiN and TiN/TiCN/TiCN/TiC/Al2O3 coated specimens which are much lower than 4 × 10−6 A/cm2 of substrate. EIS analysis confirmed the results of potentiodynamic polarization curves. Delamination of the TiN coating and formation of titanium oxide compounds on the surface of the TiN/TiCN/TiCN/TiC/TiN coating revealed that oxidative wear mechanism is dominant for this sample, while adhesive wear mechanism was dominant for the TiN/TiCN/TiCN/TiC/Al2O3 coated sample.

Wear mechanisms identification using Kelvin probe force microscopy in TiN, ZrN and TiN/ZrN hard ceramic multilayers coatings

Mechanical and tribological properties of titanium nitride, zirconium nitride, and (TiN/ZrN)n multilayers were studied to examine the potential of Kelvin probe force microscopy (KPFM) to identify wear mechanisms. Crystalline structure, chemical composition, residual stress, and the mechanical properties showed that the coatings are iso-structural polycrystalline multilayers, with a reduction of grain size, crystallite size, and compressive stress; however, hardness increased with increase in the number of the bilayers. Pin-on-disc test was used for tribological evaluation, and wear tracks were analyzed using field-emission scanning electron microscopy/energy dispersed spectroscopy (FE-SEM/EDS) and KPFM. The increase in mechanical properties generated predominantly abrasive wear mechanisms. Abrasive and adhesive wear mechanisms differentiated by KPFM demonstrated that fragile wear mechanisms presented differences in capacitance and surface potential and that the method is sensitive when the adhered material presents differences in chemical composition. We have demonstrated KPFM to be a promising technique to study tribo-oxidation processes, providing experimental evidence to understand the wear mechanisms at nanometric scales.

Effect of the Residual Porosity of CoCrMo Bearing Parts Produced by Additive Manufacturing on Wear of Polyethylene

Additive manufacturing (AM) has proven to be a flexible technique to create complex designs layer-by-layer. Among others, this versatility has disabled the production of advanced total joint replacements. The high degree of customization offered by AM provides countless opportunities to empower the fabrication accuracy of complex biomaterial constructs to tailor patient-specific implants according to their morphology and pathology. In addition, AM offers interesting microarchitecture control of surfaces, which influences biotribological performances. Porosity is an inherent defect of AM-based metallic material and has been shown to affect mechanical performances such as tensile stress. Thus, in the context of bearing surfaces of artificial joints, this article aims to understand the physical behavior of AM-created cavities on the wear performance of polyethylene in a synovial-like environment with a multidirectional pin-on-disc machine at 37 °C.The article provides quantitative ultra-high molecular weight polyethylene wear results against AM-based cobalt-based alloy parts with a gradient of cavities. The results demonstrate a strong correlation between mass loss of UHMWPE and the total surface porosity defects in the metallic counterparts. Reducing the surface porosity of AM parts is therefore beneficial for improving the wear resistance of UHMWPE.This work not only underlines the negative effect of metallic surface cavities in the wear resistance of UHMWPE but also gives some understanding of the physical behavior of metallic cavities produced by AM. The AM-created cavities modify adhesion wear and abrasion wear mechanisms. Interestingly the pores also limit the abrasive effect of a third body particles by acting as debris collector.