Pin-on Disc Research Articles

Microwave-Assisted Synthesis, Characterization and Tribological Properties of a g-C3N4/MoS2 Nanocomposite for Low Friction Coatings

This study explores the tribological performance of microwave-assisted synthesized g-C3N4/MoS2 coatings. The two-dimensional transition metal dichalcogenide (TMD) nanosheet is getting prominence in the study of tribology due to its layered structure. The graphitic carbon nitride (g-C3N4) nanosheet was made using the calcination method and its nanocomposite with molybdenum disulfide (MoS2) was produced using a microwave-assisted method. The structure and morphology of the samples were characterized by some well-known methods, and tribological properties were studied by a pin-on-disc (POD) apparatus. Morphological analysis revealed that graphitic carbon nitride and molybdenum disulfide coexisted, and the layer structured MoS2 was well dispersed on graphitic carbon nitride nanosheets. BET analysis was used to determine the pore volume and specific surface area of the synthesized materials. The inclusion of MoS2 nanoparticles caused the composite’s pore volume and specific surface area to decrease. The reduction in g-C3N4 pore volume and specific surface area confirmed that the pores of calcinated graphitic carbon nitride were filled with MoS2 nanoparticles. The tribological property of g-C3N4/MoS2 nanocomposite was systematically investigated under different factors such as applied loads (5N to 15N), sliding speed (500 to 1000 mm/s) and material composition (uncoated, MoS2-coated, 9 wt.% of g-C3N4 and 20 wt.% of g-C3N4 in the composite). The optimal composite material ratio was taken 9%, by weight of g-C3N4 in the g-C3N4/MoS2 composite for a variety of levels of loads and sliding speeds. The results indicates that the incorporation of g-C3N4 in nanocomposites could reduce friction and improve wear life, which were better than the results with single MoS2. This study demonstrates a solution to broaden the possible uses of g-C3N4 and MoS2-based materials in the field of tribology.

Corrosion and wear behaviors of brick powder reinforced aluminum composites manufactured by stir casting

Aluminum 6061 (Al6061) possesses good mechanical properties, strength, hardness, and corrosion resistance. However, the properties of Al6061 can be sufficiently raised by making composites. Metal matrix composites (MMCs) are well known for their high strength and corrosion resistance. However, these properties depend on the reinforcement materials added to the metal matrix. In the present work, Al6061-based MMCs have been manufactured by stir casting. In these MMCs, brick powders are used as reinforcement materials. Four MMCs have been developed by varying concentration and size of brick powders: MMC1, 2 h ball milled and 1% by weight; MMC2, 2 h ball milled and 7% by weight; MMC3, 4 h ball milled and 1% by weight; and MMC4, 4 h ball milled and 7% by weight. The successful formation of MMCs is examined by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray powder diffraction. The corrosion and wear resistance of the manufactured MMCs have been investigated by electrochemical measurements and a pin-on disc tribometer. Based on the results of both tests, MMCs can be ranked as MMC4 > MMC3 > MMC2 > MMC1. The reason for improved behavior can be quoted as an enhancement in overall hardness and interaction of reinforced material with the matrix. To support this statement, the Vickers hardness of Al6061 and the developed composites have also been measured.

Tribological performance of (Cr,Al)N+Mo:W:Sg in fluid-free friction regime

Highly loaded contacts in fluid-free-friction regime of uncoated gears lead to early system failures due to frictional heat and wear phenomena such as overheating, fretting as well as wear. A possibility for reducing friction and wear is the incorporation of solid-lubricants such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2) by applying physical vapor deposition (PVD) coatings. For this purpose, a (Cr,Al)N hard matrix was modified with Mo, W and S in a graded coating architecture (Cr,Al)N+Mo:W:Sg. Furthermore, coating analyses as well as tribological analyses of (Cr,Al)N+Mo:W:Sg coated 16MnCr5E specimens were conducted in fluid-free friction regime by varying the Hertzian contact pressure between 400 MPa ≤ pH ≤ 1300 MPa against uncoated 100Cr6 counter parts in a pin-on-disc (PoD) tribometer. The results show a high friction and wear reduction independent from Hertzian pressures in fluid-free friction regime. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses of the formed tribofilm prove a chemical composition of oxidic and sulfidic bindings of Mo and W. W forms sulfide-bonded mixed oxide WOmSn but not WS2 opposite to Mo which forms MoxOy and MoS2 within the tribofilm. Based on these results, synergistic effects between WOmSn, MoxOy and MoS2 were assumed.

Analysis of the corrosion and wear of WC-10Co-4Cr + GNPs coating applied to HSLA DH-36 steel using HVOF

High strength low alloy (HSLA) steels offer unique properties and features that show their utility in harsh conditions. Wear and corrosion are concerns when using HSLA steel in shipbuilding and marine environment. In such harsh conditions, WC-10Co-4Cr is a suitable candidate for applying a protective coating to HSLA steel using High Velocity Oxy-Fuel (HVOF) to improve wear and corrosion resistance. The addition of graphene nano-platelets (GNPs) to WC-10Co-4Cr powder increased its mechanical qualities due to its unique properties such as low wear and excellent corrosion resistance. In this work, WC-10Co-4Cr + 3% GNP was coated on laser-treated DH-36 steel. The corrosion potential for these coatings on pre-laser textured with pitch-to-diameter ratio 1.67 was −0.437V compared to the pristine DH-36 was −0.821V; while corrosion current density was 0.143 × 10−3 & 5.362 × 10−6, respectively. Finally, the dry sliding wear test using the Pin-on-Disc (PoD) method, microhardness using the Vickers Indentor, and corrosion resistance using a potentiometer were utilised to analyse the coated surface. The wear resistance of steel coated with WC-10Co-4Cr + 3% GNPs was about 1.5 times compared to pristine substrate. Microstructure and morphology of corroded surfaces were examined using FE-SEM. The results reveal that GNPs act as a solid lubricant, improving the surface’s wear resistance.

Wear Characteristics of 22MnB5 Boron Steel under Friction Micro Pin-On-Disks Test

22MnB5 Boron Steel can be considered as emerged material for high strength and low weight application. This material potentially used in abrasive condition such as cutting tool or brake pad where high friction resistance applies. In this study, the wear characteristics of 22MnB5 was investigated under the frictional tests via micro pin-on-disk. 22MnB5 Boron Steel was prepared the form of round shape within the size of 2.6 mm thickness and 12 mm diameter by using laser cutting. 4 different samples were tested namely blank (sample A), self-hardening heat treatment (sample B), 60 HRC hot stamped (sample C) and 70 HRC hot stamped (sample D). The results show that Coefficient of Friction (COF) increased as the hardness of 22MnB5 decreased. Low COF of 0.2114 recorded for sample D with 70 HRC hardness. The COF increased to 0.24, 0.29 and 0.3 when sample C (60 HRC), sample B (52 HRC) and sample A (45.5 HRC) applied respectively. For pin-on disc test, worn area decreased as the hardness increased. 22MnB5 that prepared with the highest hardness of 70 HRC presented smallest wear area of 700 µm x 2400 µm. It is followed by 800 µm x 2400 µm, 1000 µm x 2400 µm, 1600 µm x 2800 µm, when sample C, B and A were scratched. Observation on the worn surface revealed delamination of 22MnB5 surface in the form of fragmented flaking debris.

Effect of Mg addition on microstructure and mechanical properties of AlSi12 alloy produced by high-pressure casting method

PurposePaper aims to an alloy development study was carried out to increase the mechanical properties of cylinder heads.Design/methodology/approachAlSi12 alloys are used to manufacture the compressor head cylinder by high-pressure casting for easy casting and superior properties. Therefore, 1.1%, 2.4% and 3.1% Mg were added to AlSi12. The microstructures of the produced samples were characterized by optical microscope, scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction methods. Hardness and tensile tests as well as Charpy impact tests were performed. Wear tests were also carried out on the pin-on disc tester, and then the wear performance was examined on the tester, which simulates the actual operating condition.FindingsAlSi12 has primary Si and eutectic Si in the Al matrix. However, alloys of Mg with AlSi12 have other intermetallics such as Mg2Si and ß-Fe, as well as primary Si and eutectic Si. Hardness and tensile strength as well as improved wear performance with increased Mg content.Originality/valueIn this study, wear performance test to simulate the operation of the cylinder head produced by high pressure casting from AlSi12 alloy moreover tensile test, hardness test and impact test were performed. Therefore, in this study, the wear performance of the compressor head produced by high-pressure casting method by adding three different amounts of Mg to AlSi12 alloy was investigated.

Asymmetrical Damage Aspects Based Investigations on the Disc Brake of Long-Range UAVs through Verified Computational Coupled Approaches

In recent years, the use of unmanned aerial vehicles (UAVs) has increased significantly. Asymmetrical factors, or frictional studies on the disc brake of UAVs, are one of the safety considerations taken into consideration during the design process because UAVs and their components have been built with the best safety in mind. This study focuses on choosing the optimal material for a UAV’s disc brake by using transient structural and thermal models. In order to compare the asymmetry-based frictional force produced by the two ways; the processes used in the transient simulation are validated using pin-on-disc (POD) testing. The foundation for this validation investigation is a metal matrix composite made of an aluminum alloy, and the basis tool is an ASTM G99-based computational test specimen. Steel-EN24 and carbon ceramic matrix composites testing are expanded using the same POD tests. A range of 3 percent to 8 percent error rates is found. As a result, the calculation techniques are applied to the UAV’s disc brake after they have proven to be trustworthy. This fixed-wing UAV’s extensions have a 5 kg payload capacity. The weight, avionics components, tire dimensions, and disc brake dimensions of the other UAV design parts are calculated using analytical formulas. The final designs are made using CATIA as a result. The grid convergence experiment is organized using a traditional finite element analysis tool. Finally, at its maximum rotational speed, a UAV’s disc brake is put through asymmetrical friction testing based on structural and thermal consequences. The correct materials for critical applications, such as carbon fiber-woven-wet-based reinforced polymer and Kevlar unidirectional-49-based reinforced polymer composites for changing rotating speeds, have now been made possible by fixed-wing UAVs.

DRY SLIDING WEAR BEHAVIOUR OF CARBONATED FLY ASH FILLED COMPOSITE

Carbon Capture and Storage (CCS) has appeared as an efficient approach to alleviate the intimidating effect of the growing concentration of CO2. Recently, Fly-ash (FA), which is an industrial alkali residue and rich in metal oxides, has been proven as one of the potential agents for CCS through mineral carbonation. In this research, an attempt has been made to sequester CO2 by using FA via chemical activation technique and subsequently use this FA after carbonation (Carbonated Fly Ash (CFA)) as filler materials to fabricate a new class of glass fiber reinforced polymer (GFRP) composite. Further, the dry sliding wear properties (Pin-on disc) of these CFA composites are investigated at room temperature according to Taguchi design of experiment and the effect of diverse control factors are deliberated. The ANOVA revealed that the applied normal load and weight% of CFA significantly affect the wear rate of the presently developed CFA composites.

MULTI-RESPONSE OPTIMIZATION AND INVESTIGATION OF DRY SLIDING WEAR BEHAVIOR OF Al7075 SURFACE HYBRID NANOCOMPOSITE USING RESPONSE SURFACE METHODOLOGY

Aluminum alloy-based (Al7075) surface hybrid nanocomposite (SHNC) was fabricated by incorporating a reinforcement mixture of nano-aluminum oxide, micro-boron carbide, and graphite by utilizing friction stir processing (FSP). The graphite particle ratio was varied in the reinforcement mixture and its influence on the tribological properties of Al7075 SHNC was studied. In the metal matrix surface composite, the scanning electron microscope (SEM) and field emission SEM (FESEM) depict a homogeneity in the distribution of reinforcements. The nanocomposite’s wear behavior under dry sliding environments was investigated by adopting a central composite design (CCD) at three levels by response surface methodology (RSM). The designed experiments were executed in pin-on-disc (POD) apparatus, with load, sliding distance, and graphite ratio as input variables. The influence of applied factors and their interaction with the response were determined using an analysis of variance. To predict the wear characteristics, a mathematical model is formulated. Load is discovered to be a significant factor influencing the wear rate and friction coefficient. In addition, an increase in graphite% results in a lower wear rate for the given quantity of load and sliding distance. SEM image shows a severe wear pattern for higher load and lower graphite content. The optimum combination of the parameter obtained from multi-response optimization was load 10[Formula: see text]N, sliding distance 503.86[Formula: see text]m, and 14.99% graphite for reducing the wear rate and friction coefficient by applying the desirability function approach.

Self-lubricating CrAlMoN high performance tool coatings for machining of TiAl6V4

TiAl6V4 allows significant performance improvements in industrial applications. However, the machining is a considerable challenge due to low thermal conductivity, Young’s modulus and strong adhesion tendency. This leads to high thermal and mechanical loads on the cutting edge resulting in early tool failure. Today, uncoated cemented carbide tools are commonly used. However, temperature active physical vapor deposition (PVD) coatings like CrAlVN and CrAlMoN provide a promising approach to increase tool life. For this, the coating’s ability to form lubricating oxide phases is vital. In the present study, CrAlVN and CrAlMoN coatings were investigated to determine the more suitable version for increasing the economic efficiency of machining TiAl6V4. The coatings were deposited by hybrid direct current magnetron sputtering/high power pulsed magnetron sputtering (dcMS/HPPMS) processes. Morphology, thickness, chemical composition, indentation hardness, indentation modulus and oxide phase composition were analyzed. Moreover, friction and wear behavior of the coated tools were determined using a pin on disc (PoD) tribometer at various temperatures. Additionally, tool life and deformation behavior were analyzed after turning TiAl6V4. The CrAlVN and CrAlMoN coatings show a dense morphology and a smooth surface topography. Both variants have a good adhesion to the cemented carbide tools. For increased temperatures, the tribological analyses showed a reduction in the coefficient of friction. In case of CrAlMoN coated samples, a friction reduction compared to CrAlVN was observed at lower temperatures. Due to this, an increased tool life was achieved for CrAlMoN coated cutting inserts during turning of TiAl6V4.

Mechanical characterization of aluminium alloy LM25 reinforced with TiC and graphite for structural applications

Aluminium and its alloys are most promising materials in automobile, electronic and aviation industries. But their usage is limited because of lower strength and lower resistance towards wear and harsh environment subjected to heavy temperatures and load. Hence to improve its strength and wear resistance, ceramic particulates are to be reinforced in definite weight fractions. Similarly, to improve its wear resistance, solid lubricants too should be added. Based on this titanium carbide (TiC) ceramic particles of 0, 3, 6 and 9 wt% are reinforced in the matrix of LM25 alloy along with hybrid reinforcement of 3% graphite (Gr). Aluminium hybrid metal matrix composites (AHMMCs) are manufactured using the liquid processing approach, and their material properties, such as tensile and impact strength, and hardness, are assessed in accordance with ASTM criteria. The dispersal of particulates in aluminium matrix is visualized using optical micrographs and it is seen that uniform distribution is achieved with stir casting. It is observed from mechanical properties that with inclusion of ceramic reinforcements, tensile, impact and hardness values tend to increase. Wear studies performed on pin-on-disc (PoD) shows that with inclusion of ceramic and graphite particles lower wear loss is achieved against the unreinforced LM25 alloy.

Wear Investigation of Aluminum Alloy Surface Layers Fabricated through Friction Stir Welding Method

In this research paper, an effort was made to investigate the dry sliding wear rate of friction stir welded AA6262/AA5456 composite performed by the Taguchi approach. Wear experiments are carried out by selecting suitable process parameters such as load (LD), sliding speed (SS), and sliding distance (SE) to recognize the individual and combination effects of parameters. Orthogonal array L27 mode is applied to make numbers of experiments to find the extreme and minimum wear amount. The experimental works are conducted on Pin on Disc (POD) apparatus and measured the weight of samples before and after test for calculating wear rate (WR) and then various analyses are performed such as ANOVA, interaction plot between parameters, and regression model with support of MINITAB software. The results revealed that maximum wear rate is found as 0.01215 mm3/Nm at LD of 50 N, SE of 600 m, and SS of 4 m/s, whereas minimum 0.00414 mm3/Nm at the grouping process parameters which are LD of 30 N, SE of 400 m, and SS of 6 m/s. From the observation of ANOVA, the most significant factor is identified as load, followed by sliding distance, sliding speed, and combination of each parameter. The load is considered as main parameter which contributes about 83.75% to achieve the maximum wear rate of developed AA6262/5456 composites. The contribution of sliding distance and speed are 3.75% and 1.85%, respectively.

Evaluation of the effect of the novolac resin ratio on the high temperature performance of the brake pads

The resin is a widely used binder in the brake pads. Determining the optimum, resin ratio is important for the brake pad to show the best wear and braking performance. In this article, the impression of the novolac resin ratio (15% and 30%) on the perfor-mance of the brake pads at high temperatures was studied. Friction experiments of the brake pads were performed according to ASTM G99–95a test standard in Pin-on disc test device at 350 °C. The average friction coefficients obtained in the friction tests of 15% and 30% novolac resin samples at 500 rpm rotation speed, 350 C temperature, and 10 N load were 0.151 and 0.308, respectively. With the increase in the novolac res-in ratio, the hardness, density, and thermal conductivity of the brake pads have in-creased.

A Comparative Investigation on the Wear Performance of Compacted Graphite Iron (CGI) Treated with Single and Double Tempering

Compacted graphite iron (CGI) is a critical material in today's automotive and manufacturing industries. Heat treatment processes can improve CGI wear properties, related primarily to microstructural changes. In this study, single and double tempering heat treatments were used to improve the wear properties of CGI. Oil quenching was performed after 90 minutes of austenitization at 900°C, followed by 60 minutes of single and double tempering at three different temperatures (315, 350, and 375°C). The wear performance of the samples was compared using a pin-on disc test and hardness measurements. The volume loss and friction coefficient were evaluated, and wear maps were constructed to determine the samples' wear behavior. SEM and EDS analyses were carried out to worn surfaces to interpret the relationship between wear mechanism and microstructure. According to the study's findings, double tempering heat treatment may optimize wear performance better than traditional single tempering, and structures with high toughness-wear resistance combinations can be obtained.

AMALGAMATION, PORTRAYAL AND EFFICACY OF HELIANTHUS ANNUUS BIO LUBRICANT WITH NANO ADDITIVE

Owing to the hazardous contribution towards environment from mineral oil-based lubricants, bio-degradable lubricants extracted from vegetable oils seems to be a promising candidate considering climate change, energy security and green environmental approach. In this research work, chemically modified helianthus annuus is considered as a viable option due to its excellent tribological properties and considerable polyunsaturated fatty acid. To further enhance the tribological properties, copper oxide nanoparticles were added to the base oil in varying proportions of 0.2, 0.3 and 0.5% by weight fractions. The application of nano enhanced biolubricants on worm and gearbox is studied. The addition of copper oxide nanoparticles enhances dispersion stability of the biolubricant. Tribological characterization was conducted using pin-on disc machine. Tribological properties such as coefficient of friction and wear rate along with kinematic viscosity is analysed for each composition. The obtained results are compared with synthetic oil SAE 75. It is observed that with the inclusion of copper oxide nanoparticles to the biolubricant, there is a notable decrease in wear rate along with lower friction coefficient. KEYWORDS: Nano enchanced BioLubricants, Nano Cupric Oxide, Recycliablity, Kinematic Viscosity, Anti-Friction.

Prediction of Wear Rates of UHMWPE Bearing in Hip Joint Prosthesis with Support Vector Model and Grey Wolf Optimization

One of the greatest challenges in joint arthroplasty is to enhance the wear resistance of ultrahigh molecular weight polyethylene (UHMWPE), which is one of the most successful polymers as acetabular bearings for total hip joint prosthesis. In order to improve UHMWPE wear rates, it is necessary to develop efficient methods to predict its wear rates in various conditions and therefore help in improving its wear resistance, mechanical properties, and increasing its life span inside the body. This article presents a support vector machine using a grey wolf optimizer (SVM-GWO) hybrid regression model to predict the wear rates of UHMWPE based on published polyethylene data from pin on disc (PoD) wear experiments typically performed in the field of prosthetic hip implants. The dataset was an aggregate of 29 different PoD UHMWPE datasets collected from Google Scholar and PubMed databases, and it consisted of 129 data points. Shapley additive explanations (SHAP) values were used to interpret the presented model to identify the most important and decisive parameters that affect the wear rates of UHMWPE and, therefore, predict its wear behavior inside the body under different conditions. The results revealed that radiation doses had the highest impact on the model’s prediction, where high values of radiation doses had a negative impact on the model output. The pronounced effect of irradiation doses and surface roughness on the wear rates of polyethylene was clear in the results when average disc surface roughness R a values were below 0.05 μm, and irradiation doses were above 95 kGy produced 0 mg/MC wear rate. The proposed model proved to be a reliable and robust model for the prediction of wear rates and prioritizing factors that most significantly affect its wear rates. The proposed model can help material engineers to further design polyethylene acetabular linings via improving the wear resistance and minimizing the necessity for wear experiments.

Effect of FeTi-FeB inoculation on the shape of carbide reinforcements in hypoeutectic high chromium white cast iron

Abstract FeTi-FeB was added to molten high chromium white cast iron in amounts of 0.5–2.5 wt% at 50 °C above the melting temperature. The samples were produced in four groups. The first group samples were investigated as cast, the second group homogenized at 1000 °C for 1 h, and the other two groups were also homogenized at 1000 °C but for 3 and 6 h, respectively. To study the effect of FeB and FeTi on the microstructure, the samples were characterized by optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and hardness tests. Wear tests were performed using a pin-on disc. A homogeneously dispersed carbide microstructure was produced by the homogenization heat treatment method. The addition of FeTi-FeB inoculants to high Cr white cast iron played an important role in the distribution of hard carbides. The chemical rate and the carbide volume varied on account of the added hard inoculant particles. TiB2, Cr3C2, M7C3, M23C6, and γ-FeCr phases formed on the surfaces. The hardness and wear resistance were improved considerably due to FeTi-B inoculation.

Microstructure, mechanical and wear properties of boron carbide reinforced nickel alloy composites processed by bottom pouring type stir casting process

This experimental investigation deals with the fabrication of boron carbide (B4C) particulates reinforced Nickel based Waspaloy (WA) composite. The bottom pouring type stir casting machine under argon atmosphere was used to prepare the composites. B4C content was reinforced with Nickel based WA in the weight basis (0, 4, 8 and 12 %). The microstructure of the prepared composites was studied by using SEM and EDS. The tensile strength, impact strength, hardness and density of the samples have been reported. Then the Pin on Disc (POD) setup was used to study the wear performance of the samples. The wear parameters were analyzed by using Grey relational analysis (GRA) for the low specific wear rate (SWR) and coefficient of friction (COF) for produced composites. The addition of B4C improved the mechanical properties of the sample up to 8% and then tends to decreases. Analysis of variance (ANOVA) showed that, load is the most dominant parameter which affects the SWR of the composite. From the GRA, Load 20 N, sliding speed 1146 rpm, 12% B4C are found to be optimum parameters for minimum SWR and COF.

Optimization of adhesive wear behaviour of B4C/AZ91D-Mg composites

ABSTRACT This study elaborates about wear analysis of developed B4C/AZ91D-Mg metal matrix composites (MMCs) by a vacuum-based stir casting process having 2, 4 and 6 wt.% of B4C reinforcement in the AZ91D matrix. To illustrate the wear effect and its parameters of B4C/AZ91D-Mg MMCs, a set-up of a pin-on disc is used by employing the orthogonal L27 Taguchi and ANOVA method. For investigation, different loads, sliding speed and distance of 5 N, 10 N and 15 N, 1, 1.5, 2 m/s and 500 m, 750 m and 1000 m, respectively, have been considered. However, the statistical values signify the maximum significant wear resistance parameter and the signal-to-noise ratio measures the influence level of different parameters. Metallographic results conclude the uniform dispersion of B4C in the AZ91D-matrix, as well as the existence of the alpha Mg matrix and beta Mg17Al12 phases in B4C/AZ91D-Mg MMCs. Worn surfaces reveal acute delamination under high load conditions. However, statistical wear results conclude that load has a maximum influence on the wear rate as well as distance and velocity. Then, the results of ANOVA regression demonstrate the optimum correlation between the wear rate and its parameters. Finally, tabulated confirmation proofing and the percentage error results show less than 10% error.

Rice husk as a natural ingredient for brake friction material: A pin-on-disc investigation

The addition of the rice husk in a new eco-friendly Cu-free brake pad formulation was investigated in this study. Rice husk (RH) is a natural agro-waste residue with relatively high silica content, which should display abrasive properties that are not easily found in other natural materials. In this study, tribological properties of three friction materials were investigated using a pin-on-disc (PoD) tribometer. The three formulations were prepared adding to a common composition, each one of the following components: 6 wt% of grinded rice husk (material code: F-RH); this same amount of rice husk, after heat treatment at 600 °C (material code: F-RHT); and finally 6 wt% of alumina (F-AL) in place of rice husk, respectively. This latter material was meant to characterize the specific role of the natural ingredient. During PoD tests the evolution of the friction coefficient was followed, along with the concentration of the emitted airborne particles. The F-RHT showed very promising properties, depending on the particular characteristics of the friction layer forming onto the pin surface. This layer turned out to be compact and it was highly covering the surface of the F-RHT material, thanks to the positive effect of the silica particles from RH. The F-RH featured good behavior in terms of low wear and low emissions. In both cases, the rice husk showed up as a potential valuable alternative as a natural brake pad ingredient.