Tribological Properties Of Composite Materials Research Articles

Oil-Loaded Mesoporous Silica to Enhance the Lubrication of Polypropylene Resin Composite Materials

Polymer self-lubricating materials have advantages such as low friction coefficient, good wear resistance, and high work efficiency, giving them wide application potential in friction and wear. This work fabricated polymer-based self-lubricating materials by incorporating oil-loaded mesoporous silica nanoparticles (MSNs + YR1800) in the polypropylene resin (PP). The effects of different content of MSNs + YR1800 on the tribological and mechanical properties of the obtained self-lubricating composite materials were studied. The results indicate that the content of MSNs + YR1800 in composite materials significantly impacts their tribological properties. When the content of MSNs + YR1800 was 10 wt%, the coefficient of friction reduced to 0.09,which was 84.5% lower than for PP and 78.6% lower than for composite materials containing 5 wt% mesoporous silica nanoparticle (MSNs). Compared with pure PP, the wear rate decreases from 4.93 × 10−11 m3∙Nm−1 to 4.43 × 10−13 m3∙Nm−1, which is reduced by two orders of magnitude. The excellent tribological properties of composite materials are attributed to the high specific surface area, large pore volume, strong adsorption capacity, and high oil loading capacity of mesoporous silica nanoparticle as nanofillers. The MSNs + YR1800 release lubricants to form a lubricating oil film during the friction process under load conditions, preventing direct contact between the friction pair and the surface of the composite material. Compared with polymer-silica hybrid oil-loaded microcapsules, MSNs + YR1800 can effectively reduce lubricant leakage, prolong operation life, improve lubrication efficiency, and ensure the continuous and stable existence of lubricating oil films.

Prediction on the wear rate of epoxy composites reinforced micro-filler of the natural material residue using Taguchi – neural network

The abrasive wear rate of epoxy composites reinforced with fillers sourced from recycled natural waste consisting of pollen of palm (PPW) and seashells (SSW) was studied.
 Due to the importance of polymer composites used in the tribological couplings of machinery structures, as well as their possible use in brake pads as alternative materials for harmful components in environmentally polluted asbestos, the current research seeks to develop the tribological properties of composite materials reinforced with natural fillers and environmentally friendly. The research investigated the effect of two factors, the weight percentage of natural filler wt. % (0.5 %,1 %, and 1.5 %) and testing loads (1000 g, 2000 g, 3000 g) upon the wear resistance of epoxy composites. The importance of developing epoxy compounds is evident, especially since their work does not require lubricating conditions in various industrial fields, and therefore the development of their bonding properties will increase their operational life and achieve economic benefit for the industrial sector and the environment at the same time. The epoxy composites were subjected to abrasive wear tests under dry friction conditions using a pin-on-disc system. Signal-to-noise (S/N) analysis is adopted to study the influence of the two factors, wt. % and test loads, upon the tribological wear resistance of epoxy composites. A predictive model depending on the regression equation was developed to predict the wear resistance of epoxy composites. The results showed an improvement in the wear resistance of the composite material compared to the epoxy sample without filling by about 47 %. The optimum condition for wear resistance of epoxy composites has been achieved with a weight ratio of (1.5 %) and an applied load of 1000 g

Optimum abrasive wear resistance for epoxy composites reinforced with polyethylene (PET) waste using Taguchi design and neural network

The current work presents a study of the tribological properties of composite materials designed based on polyethylene terephthalate (PET), which has an important role in the structures of machines, represented by tribological couplings made of composite polymers. The paper examined the effect of two factors, namely recycled waste heating time (HT) and weight percentage (wt. %), on the improvement of the abrasive wear resistance of micro-filler-reinforced epoxy composites. The current research aims to develop epoxy composites by improving abrasive wear resistance while ensuring low cost and weight. Improving wear resistance due to the use of epoxy composites to connect joints that operate under conditions without lubrication in various industrial fields will increase their operational life. The signal-to-noise ratio was analyzed to find out the effect of test parameters HT and wt. % on the wear rate of epoxy composites. Using MINITAB 19 software, regression equations were obtained for each variable to compare it with the Artificial Neural Network (ANN) results. Predictive models based on the regression equation and artificial neural network were developed to predict the wear rate of epoxy composites, and to determine which model is more efficient, their results were compared and the most appropriate model with the low error was determined. The results of the current research showed that the wear resistance of epoxy composites reinforced with RCCF improved by 41 % when increasing wt. % and HT, and also showed that the ANN model is more suitable than the regression model for predicting the wear rate of epoxy composites

Determination of the influence of a filler on the properties of composite materials based on polytetrafluorothylene for tribosystems of mechanisms and machines

This paper reports a comprehensive laboratory study into the thermophysical, physical-mechanical characteristics, and tribological properties of the designed composite materials based on polytetrafluoroethylene. In the structures of machines and mechanisms, a significant role belongs to the tribological conjugations made from polymeric and polymer-composite materials. The reliability of machines, in general, depends to a large extent on the reliability of movable connections. Composite materials of nonmetallic origin have a low cost, they are resistant to most aggressive chemicals and are capable of operating under conditions without lubrication. It was established that the characteristics and properties of materials must be adapted to the working conditions of separately considered tribological conjugations. The mechanisms of thermal destruction have been established, both in the basic material and the carbon fiber based on it. It was found that carbon fiber, regardless of its content (quantity) in the polymer-composite material based on polytetrafluoroethylene, is mainly oriented perpendicular to the force application plane. It was found that with an increase in the carbon fiber content from 10 to 40 % by weight, the heat capacity decreases by 16‒39 % compared to the main material. The optimal operating modes for the designed composite materials have been substantiated on the basis of a pv factor: under a dry friction mode – up to 4 MPa∙m/s; at friction with lubrication – up to 36.4 MPa∙m/s. The dependence has been established of the friction coefficient on the operating modes of a composite material based on polytetrafluoroethylene containing 20 % by weight of carbon fiber when lubricated with oil and water. The results reported here make it possible to synthesize the physical-mechanical characteristics and tribological properties of composite materials in accordance with the required modes of tribological conjugation.

Effects of ionic liquid types on the tribological, mechanical, and thermal properties of ionic liquid modified graphene/polyimide shape memory composites

Different ionic liquid modified graphene nanosheets (IG) were induced into polyimide (PI) to improve the tribological, thermal, and mechanical properties of shape memory IG/PI composites. The results demonstrated that when using 1-aminoethyl-3-methylimidazole bromide to modify graphene nanosheets (IG-1), the laser-driven shape recovery rate of IG-1/PI composites (IGPI-1) reached 73.02%, which was 49.36% higher than that of pure PI. In addition, the IGPI-1 composite materials reached the maximum shape recovery rate within 15 s. Additionally, under dry sliding, the addition of IG can significantly improve the tribological properties of composite materials. IGPI-1 exhibited the best self-lubricating properties. Compared with pure PI, the friction coefficient (0.19) and wear rate (2.62 × 10–5) mm3/Nm) were reduced by 44.1% and 24.2%, respectively, and the T10% of IGPI-1 increased by 32.2°C. The Tg of IGPI-1 reached 256.5°C, which was 8.4°C higher than that of pure PI. In addition, the tensile strength and modulus of IGPI-1 reached 82.3 MPa and 1.18 GPa, which were significantly increased by 33.6% and 29.8%, respectively, compared with pure PI. We hope that this work will be helpful for the preparation of shape memory materials with excellent tribological, thermal, and mechanical properties.

Review of composite metal polymers reinforced with nano- and ultra-dispersed particles

The results of studies of the structure, mechanical and tribological properties of composite materials based on polytetrafluoroethylene and simple (Al2O3, Cr2O3, ZrO2) and complex (spinels CoA12O3 and MgAl2O4, and cordierite 2MgO—2Al2O35SiO2) oxide nanopowders are presented; as well as amorphous polyvinyl chloride with heat stabilizers and elastomeric additives. Investigations of thin-layer fluorine-containing coatings with a polymer matrix modified by nano- and ultra-fine particles of diamond-containing graphite by atomic force microscopy are presented.

Metal-polymer composites with ultra-and nanodisperse particles

The results of studies of the structure, mechanical and tribological properties of composite materials based on polytetrafluoroethylene (PTFE) and simple (Al2 O3, Cr2 O3, ZrO2) and complex (spinels CoAl2 O3 and MgAl2 O4, and cordierite 2MgO · 2Al2 O3 · 5SiO2) oxide nanopowders, as well as amorphous polyvinyl chloride (PVC) with heat stabilizers and elastomeric additives, are presented.

The Influence of Mechanical Treatment Type on the Tribological Properties of Flame Sprayed Ni-5% Al-15% Al2O3 Composite Coatings

During operation of marine pumps, one of the most common disability is tribological wear of shaftneck cooperating with the gland. In the practice, worn shafts are exchanged for new or are regenerated bychromium plating, padding or thermally sprayed of ceramic coatings, mainly Al2O3. In this article, the use offlame sprayed Ni-5%Al-15%Al2O3 composite coatings were proposed. The surfaces of coatings by turning,grinding are burnishing treatments were formed. Tribological properties of composite materials are dependent onthe proportion and size of the reinforcing phase particles contained in a metal matrix. A reinforcement compositewith very small dimensions and the amounts may result in increased wear and increase the coefficient of friction.It is therefore important to check whether the advisable of phase composition will not adversely affect the wearof the composite and the cooperating the part. The presence of a 15% volume fraction of the alumina particles onthe selected tribological properties of the Ni-5%Al matrix composite coatings were evaluated. In order to assessthe effect of the applied tapes of finishing on wear of composite coatings, the tribological tests were performedon the "T05" tribometer with head roll- piece type. It has been found that the burnishing favors a lower wear ofcomposite coating and the cooperating element compared to the coatings after turning treatments. At the sametime observed more than ten times less wear intensity of composite coatings in the initial time of friction, whichmay indicate a shorter time needed to running-in of cooperating elements.

Self-lubricating composites with 2D materials as reinforcement: A new perspective

In recent years, composite materials have acquired vast potential in the automotive, aerospace, marine and defence sectors due to suitable mechanical and physical properties. On the other hand, these composites limit their application due to the inferior tribological properties. To improve the tribological properties of composite materials, researchers have suggested the introduction of solid lubricants as a reinforcing phase in the matrix phase for the fabrication of composite materials, which will reduce the friction. Apart from different types of solid lubricants, 2D materials such as graphene, WS2, and MoS2 have emerged as novel solid lubricants with a greater potential to reduce friction. The present paper discusses self-lubrication composite materials, types of 2D solid lubricants, and future challenges and opportunities.

The research on the influence of titanium-tantalum-tungsten-cobalt hard alloy on the tribological properties of phenylone C-2

Polymer composite materials based on aromatic polyamides, filled with dispersed fillers (metal powders, graphite, silicon dioxide and titanium, etc.) are some of the most widely used tribotechnical materials for friction nоdes and machinery for automobile and agricultural machinery now. The use of dispersion-hardened polymer composite materials can reduce the cost of manufacturing details at the same time increasing their reliability and working resource. The influence of the content of titanium-tantalum-tungsten-cobalt hard alloy on the tribological properties of composite materials based on phenylone C-2 aromatic polyamide is considered in the article. It has been found that the introduction of titanium-tantalum-tungsten-cobalt hard alloy reduces the intensity of linear wear and abrasion index of phenylone by 35 and 20%, respectively. It has also been found that the effective content of the filler in the polymer binder is 3 mass.%. Taking into account all the above, this material can be recommended for the manufacturing of parts of vehicles, road cars and agricultural machines that operate in aggressive conditions, at elevated temperatures, under the influence of abrasive particles and variable loads

Determination of Mechanical and Friction Properties of Carbon Composites at Different Scale Levels

Abstract—A comprehensive study of the mechanical and tribological properties of composite materials developed for damping washers used in ball-screw pairs at the micro- and nanolevel has been carried out out. The study includes determination of the local elastic properties of elements of a composite material using atomic force microscopy, and integrated elastic properties, by indentation. The results obtained at the nano- and microlevels are compared. A method for determining the friction coefficient at the micro level has been developed. It is shown that the Amonton–Coulomb law is satisfied for the considered friction pair.

Polydopamine-coupling of carbon nanotubes onto microscaled basalt fiber to enhancing mechanical, thermal and tribological properties of composite materials

Under mild and green conditions, carbon nanotubes (CNT) were grafted onto the surface of basalt fiber (BF) via polydopamine (PDA) as coupling agent in an attempt to improve mechanical, thermal and tribological properties of BF composites. It showed CNT were coated uniformly and formed a thick flocculent cladding layer on the surface of BF. With improved interfacial interaction supported by chemical coupling and mechanical meshing between BF and matrix, impact strength, flexural strength and flexural modulus of the CNT grafting BF (CNT-PDA-BF) composites increased by 28%, 23% and 24%, respectively. Besides, thermal conductivity of the CNT-PDA-BF composites increased by 24% and thermal stability also improved. Furthermore, cracks on the worn surface of CNT-PDA-BF composites almost disappeared, wear debris became smaller and roughness significantly decreased, thus wear resistance of the BF composites improved 36%. Therefore, it provided a novel and effective surface modification method for improving comprehensive performance of BF composites.

Friction characteristics of protein-glucose-thermoset composites

Polymers are materials with a great spread and represent the center of the life comfort development. They have become since their discovery, indispensable to a modern prosperous society. In order to obtain optimal performance of the composite material, a broad variety of organic modification agents were used. The purpose of this study represents the development of modern composite materials modified with glucose particles and protein substances (gelatin and wheat gluten). The glucose-modified composite materials are used in the medical field.Gelatin is a protein derived from collagen, being bio-compatible and nontoxic. Wheat gluten is a vegetable protein used as a modifying agent to form composite materials that can be transformed into a bioplastic material. The following types of epoxy resins were used for this study: Epyphen RE 4020, Epoxy RESIN C, Epoxy RESIN HT. These composite materials are designed to withstand some mechanical, physicochemical, thermal properties and most valuable, tribological properties. Tribological tests aim to determine the friction coefficient. These tests are necessary to understand the tribological properties of composite materials and the field in which they can be used.

The Investigation of Tribological Properties of Epoxy-Polyether Composite Materials for Using in the Friction Units of Means of Sea Transport

Abstract The tribological properties of composite materials with microdispersed proportions, based on the epoxy-polyether matrix, were investigated. The specimens were tested during dry friction and in the conditions of a corrosive environment. It was determined that at dry friction, the coefficient of friction is f = 0.33–0.35, and the contact temperature of the experimental specimen in the area of mechanical interaction of surfaces is T = 366–369 К. It was proved that composites, which were tested in the conditions of a corrosive environment, differ with improved antifriction properties and increased durability. In this case, the coefficient of friction is f = 0.08–0.09, and the contact temperature in the friction area is T = 295–298 К. It was stated that the wetting of the surface of the friction and heat removal from its area significantly affects the properties of the polymer during friction. In particular, the work surface of the source material and polymer, after testing in different conditions, was analyzed with the methods of optical and electron microscopy. The presence of lines of friction and microcracking of specimens at elevated temperatures was revealed. The elemental composition of the surfaces of materials in different areas was investigated with the help of X-ray microanalysis. The presence of selective transfer effect during the testing was ascertained as a result of analysis of the elemental composition.

Structure and tribological properties of composite materials based on Al–Cu–Fe formed at high pressure

The use of high pressure (~8 GPa) in the formation of composite quasi-crystalline materials from powders made it possible to create practically poreless samples with a density close to the maximum known for this type of quasi-crystals. For samples with a nickel binder, sintered at a temperature of 550°C, a very low coefficient of friction was obtained, which retain its value during the testing.

TRIBOLOGICAL TESTS OF THE NANOMATERIALS USED TO RECONSTRUCT MOLARS AND PREMOLARS WITH THE APPLICATION OF THE DIRECT METHOD

Physiological abrasion of teeth is a process of gradual loss of the hard tissue of opposite teeth resulting from age-related natural dental wear. In abrasion, the cusps and their slopes in the jaw and the mandible become flattened due to the mechanical load applied. The aim of this paper is to carry out a tribological and microstructural evaluation of modern composite materials used to reconstruct the teeth in the lateral part of the dental arch. Five light-cured composite materials were selected for tests. The tests involved the coefficient of friction and resistance to wear in a sliding contact in the presence of artificial saliva and the microstructure of the external surface of samples before the wear process and in the wear-related damaged area. The test method applied, which combines a biomechanical analysis of resistance to wear and the analysis of the microstructure before the wear process and in the wear-related damaged area, makes it possible to evaluate the tribological properties of composite materials used to reconstruct teeth in the lateral part of the dental arch.

STUDY THE EFFECT OF FILLER DISPERSION ON THE STRUCTURE AND PROPERTIES OF ULTRA-HIGH MOLECULAR WEIGHT POLYETHYLENE

With the purpose of studying the effects of filler dispersion on the structure, mechanical and tribological properties of composite materials based on Ultra-high molecular weight Polyethylene (UHMWPE), we have used Polytetrafluoroethylene (PTFE) with different sizes. The experimental results showed that when adding small filler (Ø 10 µm) structure of composites is more homogeneous, mechanical properties decrease less and the wear resistance under dry sliding friction is higher 2 times than adding large filler (Ø 100-180 µm). Identified the best weight content of filler to increase the wear resistance for composites based on UHMWPE. The obtained results in order to overcome the limitations of structure and elongation, tensile strength of composites were discussed.

Electrical and tribological properties of composite material with copper matrix reinforced by superelastic hard carbon

Electrical and tribological properties of a copper-based composite material reinforced by superelastic hard carbon particles are studied. Composite material specimens have been produced using the hightemperature pressing of mixtures of copper and fullerene powders. Electrical and tribological reciprocal tests carried out using the plane-on-plane arrangement have shown that the coefficient of friction of the composite material–Ni pair is lower than that of the reference L63 brass–Ni pair at similar values of contact electrical resistance. The abrasive wear resistance of the composite material is 40 times higher than that of brass. The developed copper-based composite materials reinforced by superelastic carbon particles hold promise for use in sliding electrical contacts.

Strategic process optimisation for tribological behaviour of silica gel reinforced aluminium composite material by neuro-grey modelling

Rotating and reciprocating parts requires low friction and high wear resistance for better life. Material like aluminium and its alloys, used largely in manufacturing/automotive sector, has the disadvantage of poor mechanical and tribological properties. In order to enhance the same the usage of aluminium-silicon composites are being rapid increased. In this work, silica gel reinforced aluminium composite was prepared to examine the tribological behavior. Plan of experiment was developed on the basis of three levels and three factors with Taguchi method initially. Proposed multi-objective optimisation problem was solved by neuro-grey modelling by using design including multiple attributes characterisation. The combined approach of ANN and GRA successfully overcomes the limitations of each other and provides with better solution. Experimental results show the efficacy of using such heuristics to highlight tribological properties of composite materials and any decision maker may opt for such strategy to make their operations more efficient.

Strategic process optimisation for tribological behaviour of silica gel reinforced aluminium composite material by neuro-grey modelling

Rotating and reciprocating parts requires low friction and high wear resistance for better life. Material like aluminium and its alloys, used largely in manufacturing/automotive sector, has the disadvantage of poor mechanical and tribological properties. In order to enhance the same the usage of aluminium-silicon composites are being rapid increased. In this work, silica gel reinforced aluminium composite was prepared to examine the tribological behavior. Plan of experiment was developed on the basis of three levels and three factors with Taguchi method initially. Proposed multi-objective optimisation problem was solved by neuro-grey modelling by using design including multiple attributes characterisation. The combined approach of ANN and GRA successfully overcomes the limitations of each other and provides with better solution. Experimental results show the efficacy of using such heuristics to highlight tribological properties of composite materials and any decision maker may opt for such strategy to make their operations more efficient.