Adhesive Wear Tests Research Articles

Analysis of the effect of boric acid and compatibilizer addition to polylactic acid/basalt fiber composites

AbstractThe objective of this study is to improve the properties of polylactic acid (PLA), a biopolymer produced from renewable resources, without compromising its environmentally friendly “natural composite” properties. The aim was to expand the application range of PLA by making it suitable for the production of high performance composites. With this in mind, it was decided to use inorganic and environmentally friendly materials such as basalt fiber (BF) and boric acid (BA) as reinforcements. Adhesive wear and tensile tests were used to investigate the tribological and mechanical performance of the composites. Differential scanning calorimetry (DSC) and dimensional stability analysis (DSA) methods were used to investigate the thermal properties. Scanning electron microscopy analysis was also used to investigate the morphological properties of the samples. In addition, a matrix modification process using Joncryl®, an epoxy‐based chain extender chemical, was applied to enhance the interfacial interaction between the composite components and improve the composite properties by improving the dispersion of reinforcing materials. As a result of the characterization tests, it was observed that a significant improvement in the properties of the material type containing 10 wt% BF, 0.25 wt% BA and 2 wt% Joncryl® was achieved. A 19% increase in tensile strength of this type of material was observed compared with unreinforced PLA, while the sharp peak increase in the coefficient of friction (COF) curve was shifted from 20 m to 60 m. As a result, it has been presented that environmentally friendly and inorganic materials such as BF and BA can be used to produce composite materials that will serve sectors where the need and use of high performance materials is intense, especially in the automotive, aerospace and aviation sectors.Highlights The properties of PLA matrix composites were improved by the simultaneous use of BF and BA and the addition of Joncryl®. The structural properties of PLA, an environmentally friendly polymer, have been improved without compromising this characteristic. PLA matrix natural composites with performance that can be used in the automotive, aerospace and aviation sectors have been developed.

Effects of Adding Graphite to Epoxy Resin on its Mechanical Properties and Mild-to-Severe Wear Performance at its Heat Distortion Temperature

In this study, epoxy/graphite composites were fabricated based on different weight fractions (0, 3, 6, and 9 wt.%) of graphite powder for bearing applications. The mechanical and tribological properties were assessed. Adhesive wear tests covered the severe regions, where the interface temperature (IFT) exceeded the heat distortion temperature (HDT) of the epoxy. Graphite additions improved elastic modulus and hardness but decreased fracture strain and toughness of the composites. The tribological behaviors in the mild wear region were improved as the graphite content increased. In the mild wear region, the increase in graphite additions showed a good improvement by reducing the specific wear rate (SWR) and coefficient of friction (COF). In the severe wear region, the neat epoxy and higher graphite concentrations exhibited a dramatic increase in SWR, whereas the lowest addition of 3 wt.% exhibited good wear performance. For epoxy, the reason was that IFT exceeded its HDT, while the aggregation of graphite particles was the main reason in the case of higher graphite concentrations. SEM examinations showed severe wear signs—high ploughing and fracture—when IFT exceeded the HDT. However, by reducing the IFT, graphite additions did not show such severe wear features due to the accelerated heat dissipation.

Measuring applied force and energy consumption in deep drawing die Sets: An experimental and numerical analysis of CrN and CrTiN PVD coating effects

Excessive forming loads ultimately result in wear during the deep drawing process. This study uses an innovative test rig on a universal testing machine to monitor force–time variations during deep drawing. The rig captures force changes, workpiece/die friction, and energy consumption. The research explores how varying friction coefficients between the die and workpiece, lubrication conditions, and different PVD coatings on the die surfaces affect production performance in deep drawing. Various coatings were applied to 1.2379 cold work steel samples, and their friction behavior was examined. The performance of PVD-coated die sets was evaluated through experimental and numerical methods. The abrasive wear test revealed that the CrN coating had 46 % less wear volume than uncoated specimens. In contrast, the CrTiN coating showed 70 % more abrasion volume at 15 N load and 96.4 % less at 30 N load compared to CrN. Adhesive wear tests demonstrated that CrTiN had 9.09 % less wear at 6 N load and 27.66 % less at 10 N compared to CrN. Numerical simulations explored friction's impact on deep drawing; CrTiN die set used least energy, forming with lowest max force, while CrN set reduced max force by 0.56 %. CrTiN coating showcased better wear resistance, lower forming forces, and reduced energy consumption than CrN and uncoated dies under various friction conditions.

Carbon fiber reinforced poly(lactic acid) composites: Investigation the effects of graphene nanoplatelet and coupling agent addition

Although petroleum-based polymers require a long process to decompose in nature, they still have a wide range of uses. However, due to many important reasons such as the environmental pollution problem caused by these polymers, there is an increasing interest in biodegradable polymers. Poly(lactic acid) (PLA) is a biopolymer with comparable performance to conventional polymers. However, due to its poor tribological, mechanical and thermal properties, the usage area of PLA cannot expand and its use is limited to short-term material applications. In this study, it was aimed to contribute to the expansion of the usage area of PLA by improving its poor properties. For this purpose, efficiency of graphene nanoplatelet (GnP) and/or Joncryl® addition to carbon fiber (CF) reinforced PLA matrix composites to improve the composite performance by means of improved interface interaction fiber and matrix was investigated. Within this scope, effects the separately and/or simultaneously addition of CF, GnP and Joncryl® to PLA on properties were investigated by tensile test, adhesive wear test, DSC, TGA and SEM analyses. All results revealed that the composite composition prepared by simultaneously addition of 10, 0.5 and 2 wt.% CF, GnP and Joncryl®, respectively, to pure PLA performed the best in all tests and analyses.

Study of Adhesive Wear Test on TiSi, AlTi, and WTi Coatings

Coatings based on Ti, Si, W, and Al synthesized by different techniques have been investigated in order to better understand their properties; however, there are few results related to their wear behavior. In this paper, TiSi, AlTi, and WTi coatings were applied by means of a sputtering system on 316L stainless steel substrates in order to evaluate their behavior through a ball-on-disc wear test. Adhesive wear tests were carried out using the ball-on-disc technique, which allowed the coefficient of friction to be measured. The morphological characterization was based on an analysis of the SEM images and on the optical profilometry of the wear traces of the coatings, used to calculate the wear rate. An analysis of the wear products was carried out based on information provided by the SEM-EDS, Raman spectroscopy, and XPS techniques, which provided information about the tribo-chemical behavior of the coatings subjected to the ball-on-disc test. The morphological analysis showed that the TiSi and AlTi coatings exhibited premature failure, which was corroborated by means of the coefficient of friction curves. It was also observed that the WTi coating exhibited better behavior against the wear test, with a coefficient of friction lower than that of the stainless-steel substrate, without showing evidence of premature failure, which can be explained as a consequence of the tribo-chemical behavior of the WxOy produced in the coating.

From polymeric waste to potential industrial product: Modification of recycled polycarbonate

The aim of this study is to investigate the effects of simultaneous addition of chain extender and impact strength modifier on tribological, mechanical, thermomechanical and morphological properties of recycled polycarbonate (r-PC). Mechanical properties of the samples were evaluated by using essential work of fracture method and tensile tests. Tribological properties were investigated by means of adhesive wear test. Thermomechanical properties were investigated by using dynamic mechanical analysis. As a result of the study, different types of samples were obtained, which simultaneously contained chain extender and impact strength modifier and exhibit improved fracture toughness, adhesive wear performance, storage modulus and not deteriorated tensile strength compared to neat r-PC. Thus, in this study, a solution alternative for both the expanding of the usage area of r-PC and waste management of it has been presented.

A study of the pack carburizing quenching treatment with cane molasses cooling medium effect on the wear resistance of low carbon steel

In the present study, various quenching media were added as cooling media for the quenching after pack carburizing treatment. The aim of this research is to get a suitable cooling medium for pack carburizing quenching treatment to increase the wear resistance of low carbon steel. Many cylindrical specimens for the adhesion wear tests were prepared from the used SS400 steel according to ASTM G99-04 specifications. Two heat treatment processes, namely pack carburizing and quenching were done. Firstly, the specimens are pack-carburized at a temperature of 875 °C, soaking time of 2 hours and quenched. The carburizing agent consists of Pinctada maxima shell powder (PMSP) and corn cob charcoal with a weight ratio of 30:70 %. Different cooling media (water, 10 % NaCl solution, 10 % cane molasses) in the pack carburizing quenching treatment are subjected to different kinds of tests. The hardness test was performed using Vickers micro hardness tester, the wear resistance was used in adhesive wear test, the carbon content was determined and microstructure examination was made using a scanning electron microscope (SEM-EDX). The result showed that all cooling media contributed to an increase in mechanical properties (surface hardness number, wear resistance), carbon content and microstructure change. The use of cooling media in the pack carburizing quenching process generally increases the surface hardness number of the specimen. The highest surface hardness number was 595 kg/mm2, respectively using 10 % cane molasses. The work shows that cane molasses can be used as a cooling medium for pack carburizing quenching of SS400 steel and contributed to the improvement of wear resistance

Investigation of adhesive wear properties of glass fiber reinforced polyester composites having different chemical compositions

Glass fiber reinforced polyester composite materials are widely used in various areas due to their high specific strength, low weight, excellent elasticity, high corrosion resistance, and high thermal stability. This study aims to investigate the effects of resin materials and various fillers and wear parameters such as different loads and speeds on the tribological properties of glass fiber reinforced polyester composite materials. In this experimental study, various resins (tensile additive orthophthalic polyester and plain orthophthalic polyester), fillers (alumina and glass beads), and reinforcing materials were used during the sample preparation. The samples were subjected to an adhesive wear test at two different speeds ( n = 100 r/min and n = 200 r/min) and different loads ( F = 10 N and F = 20 N) at 150 m sliding distance. The friction coefficient and friction force were measured by the tribometer. The thickness of the wear trace was later measured and the wear rate was calculated. Wear surfaces of samples were visualized with a three-dimensional laser profilometer in order to obtain surface topographies and surface roughness values. The sample surfaces were examined by scanning electron microscopy in order to understand the wear mechanisms and to characterize the morphology of worn surfaces. Experimental results have shown that alumina or glass beads fillers can reduce the average friction coefficient when used in the correct amounts. The use of glass bead filler in orthophthalic polyester resin with tensile additive is more effective than reducing the wear rate compared to alumina filler. The load on the wear behavior of glass fiber reinforced polyester composite materials is more effective than the speed.

Influence of graphene nanoplatelets on mechanical properties and adhesive wear performance of epoxy-based composites

Epoxy resin is one of the most widely used thermoset polymers in high-performance composite materials for lightweight applications. However, epoxy has a high coefficient of friction, which limits its tribological applications. In this study, the effect was investigated of different weight fractions of solid lubricant graphene nanoplatelets (GNPs), ranging from 0 to 4.5 wt%, on mechanical and adhesive wear performance of epoxy. Adhesive wear tests covered mild and severe wear regimes. The correlation of tribological and mechanical properties was studied as well. Scanning electron microscopy (SEM) was used to observe the failure mechanisms for both tribological and mechanical samples after each test. The results revealed that the addition of GNPs to the epoxy improved its stiffness and hardness but reduced its fracture strength and toughness. Adhesive wear performance exhibited high efficiency with GNP additions and showed reductions in the specific wear rate, the coefficient of friction, and the induced interface temperature by 76%, 37%, and 22%, respectively. A fatigue wear mechanism was predominant as the applied load increased. Most importantly, severe wear signs occurred when the interface temperature reached the heat distortion temperature of the epoxy. The tribological, and mechanical properties showed only a weak correlation to each other. The addition of GNPs to epoxy by less than 4.5 wt% was highly efficient to improve the wear performance while maintaining the fracture strength and toughness. Fourier transform infrared spectroscopy (FTIR) analysis shows no chemical interaction between the epoxy matrix with GNPs, which implies its physical interaction.

Influence of graphene nanoplatelets on tribological properties of short carbon fibre reinforced PA-66/TCE composites

Graphene nanoplatelets (GNPs) modified thermoplastic-polymer based composite structures can be used as lightweight, damping, high strength, and tribo-elements in food processing machinery where traditional single materials become unproductive. In the present research work, novel GNPs modified polyamide 66/thermoplastic copolyester elastomer (PA 66/TCE) composite reinforced with short carbon fibres were developed. The possible structural changes of the materials by Fourier transformed infrared (FTIR) technique and the wear performance of the fabricated composites were investigated in adhesive wear and abrasive wear modes. Adhesive wear test was carried out at 1000, 3000, and 5000 m sliding distances and 50 N applied load and at 2 ms −1 sliding velocity. In case of abrasive wear, tests have been conducted at 300, 450, and 600 m abrading distances and at an applied normal load of 20 N using 425 µm silica sand particles as abrasives. For the GNPs modified PA 66/TCE hybrid composites used in this investigation, the friction coefficient increases with an increase in sliding distance and the specific wear rate decreased with an increase in sliding distance. Furthermore, superior wear performance was observed in 3 wt% GNPs modified PA 66/TCE hybrid composite. However, under three-body abrasion, the specific wear rate decreases with increase in abrading distance and the superior abrasion resistance were found in 1 wt% GNPs modified PA 66/TCE hybrid composites. Finally, the microscopy indicated significant differences in the wear mechanisms in each adhesive and abrasive wear modes.

Cyanide in salt bath Applied to ASTM A-517 Steel Effects on Hardness Wear and Microstructure

The effects of the cyanide treatment (CN) in a salt bath at elevated temperatures on the hardness; adhesive and abrasive wear; of ASTM A-517 steel, were investigated. For abrasive wear, 1” x 3” x 5/16″ samples were prepared according to ASTM G-65 standard. For adhesive wear, specimens wit ring-shaped: φ ext. = 40 mm, φ int = 20 mm and 10 mm thick, according to ASTM G -77. The CN treatment was carried out, at high temperatures: 800 – 850 – 900 – 950 °C, immersing the samples in a salt bath: 6% NaCN + 80% BaCl2 + 14% NaCl before entering the muffle furnace, with soaking time of 3 hr. Hardness tests were performed on a Rockwell Durometer taking measurements on the HRC scale. The adhesive wear tests were carried out on a parallel lathe coupling the Amsler device, following the ASTM G-77 standard. The abrasive wear tests were performed according to the ASTM G65 standard. Microscopy was done at the optical level. A maximum hardness of 63.5 HRC was found in all samples, representing an increase of 11.3% with respect to the state of supply (T&R). In abrasive wear, its value increased to 66%, compared to supply samples. The most suitable microstructure is presented by cyanide samples at 850ºC, with a layer of compounds (hard layer) formed by: massive cementite; tempered martensite and carbide. It is concluded that when applying cyanide to ASTM A-517 steel, the hardness and wear properties are increased to optimal values, if the cyanide treatment (CN) is carried out at 850 °C.

Mechanical effort of ceramic particle-reinforced epoxy matrix used as a sealing layer on aluminum coatings by Arco Spray

The coating against the corrosion and wear of carbon steel with pure aluminum applied by thermal projection with electric arc (arc spray) presents a porous surface. This is the reason why adding a sealing with a polymer layer, regularly epoxy is necessary. However, epoxy-based sealing solutions usually do not have high performance against abrasive wear. In this research a new product has been developed in composite material with polymer matrix (PMCs), epoxy paint reinforced with ceramic particles, in order to improve the performance of this layer against abrasive wear. Preliminary runs were made with 3 variables: Epoxy matrix (2 types: epoxy S and epoxy C); Size of reinforcing ceramic particles (two levels: 1 μm 9 μm) and percentage of ceramic reinforcement (4 levels: 0%, 20 %, 33.3% and 50 %). Adhesion and abrasive wear tests were performed to show that the composite material with epoxy matrix type C, has better performance than the composite material with epoxy matrix type S. Increasing the percentage of reinforcement particles showed that the composite material with type C epoxy matrix maintained high levels of adhesion to the aluminum layer and showed an increase in abrasive wear resistance by about 60% compared to the resin without reinforcements.

Development of the Wear Resistant Ball Nut Assembly in the Rack-Based Electric Power Steering

Electric Power Steering (EPS) is rapidly evolving in terms of performance. However, the abnormal noise from steering, which is experienced by the drivers, reduces the perfection of performance. In this study, the deterioration of Rack-based Electric Power Steering (R-EPS) samples by mileage was analyzed to investigate the cause of steering abnormal noise in the R-EPS applied to a large-sized luxury vehicle that is more sensitive to noise. The results from our analysis showed that the ball nut and screw in the ball nut assembly of R-EPS were in the mode of normal wear. However, the steel ball between the ball nut and screw showed irregular wear mode. It was found that the ball Φ5 has a larger contact area than the ball Φ4, which is advantageous for abrasion and irregular wear because stress is dispersed in the load. Moreover, the ball with Φ5 was superior to the ball with Φ4 in the results of abrasive and adhesive wear tests verified by the ball-on-disk test. Therefore, in the future R-EPS development, the ball with Φ5 compare to the ball with Φ4 should be proposed for the ball nut assembly. This is in order to eliminate the potential cause of steering abnormal noise.

Effect of ion bombardment and micro-blasting on the wear resistance properties of hard TiN coatings

Ion bombardment (IB) is conventionally used as a pre-coating treatment process to increase surface energy of tools to improve the adhesion of coatings produced using cathodic arc Physical Vapour Deposition (CA-PVD) technique. Micro-blasting (MB) as a post-treatment process is used to improve the surface finish of the coated tools. Both these processes impact surface finish, adhesion and wear resistance of the coated tools. This article presents a systematic study to understand the effects of these two processes on the surface finish, adhesion and wear resistance properties of TiN coated HSS substrate. IB process was carried out using Ti ions for different time periods which results in the formation of Ti layer on HSS M2 grade substrate. This was followed by TiN coating deposited at −150 V bias voltage and 1.3 Pa of nitrogen gas. Coating properties evaluated were: coating micro-structure, surface morphology, surface roughness, macroparticle (droplet) density, adhesion and wear rate. TiN coating with FCC structure was confirmed using XRD measurements. With the decrease in IB time from 25 min to 5 min, the surface roughness reduces from 0.31 µm to 0.15 µm respectively. Adhesion and Calo wear tests also showed improvement in adhesion and wear resistance with the reduction in IB time. The TiN coated sample without IB process was also prepared, which exhibited lowest surface roughness and droplet density, but the coating adhesion and wear resistance properties were optimum for 5 min IB treated HSS. The Ti layer deposited during the IB process helps in improving the coating adhesion. However, as the result shows, higher Ti inter-layer thickness results in poor adhesion and higher roughness. Thus, to get better wear resistance and adhesion, ion bombardment is necessary but has to be kept as low as possible. In addition, Post-coating MB process was carried out at different pressures and time on TiN coated sample to identify the optimum pressure and time which improves wear resistance of the coating.

Effect of matrix material and orientation angle on tensile and tribological behavior of jute reinforced composites

Abstract Environmental friendly natural fibers have been used instead of petroleum-based synthetic fibers as reinforcements because of the depletion of oil resources, plastic waste disposal problems and the emissions generated during combustion. In these natural fibers, thermoplastic or thermoset materials are used as matrix material because of their low cost, light weight and durability. In this study, the effects of ply number (2 and 3 layer) and orientation angle of reinforcement (0/90° and ± 45°) and matrix type (thermoset and thermoplastic) on the tensile strength of jute reinforced composites were investigated. Also, the effect of the reinforcement orientation angle, sliding time (600, 1200 and 1800 s) and applied load (5, 10 and 15 N) on tribological characteristics were determined. Adhesive and abrasion wear tests were carried out at 0.15 m × s−1 sliding speed. It was observed that the matrix material and the reinforcement are very important in tensile and wear tests, while the ply number and the orientation angle only exert an influence in the tensile strength of composites. It was determined that an increase in load and sliding time is the most effective parameter on wear experiments.

Tribological behavior of magnetron sputtered nanocomposite coatings on base of Cu-Mo-S

Tribological properties of solid lubricant electrical conductive magnetron coatings based on the Cu-Mo-S system were studied. Wear resistance increasing and lubricating mechanisms of the coating during adhesive wear tests in inert atmosphere has been demonstrating.

Validation of cyanide copper electrodeposited layer on test coupons for anti-seizing and outgassing in Tokamak vacuum vessel

A vacuum vessel which is the first confinement barrier of Tokamak fusion reactor should have numerous in-vessel components. Since those components are to be exposed to the plasma under ultrahigh vacuum condition and should be maintained during Tokamak operation, a threaded connection of vacuum vessel and in-vessel components is necessary. The threaded connection of stainless steel with the components causes difficulties during assembly or disassembly due to the large friction coefficient of stainless steel. To resolve this issue, anti-seize coating that does not affect the mechanical property, thermal stability, and outgassing rate of the threaded insert needs to be developed. In this study, adhesion, porosity, outgassing, and friction wear tests for a cyanide copper electrodeposited surface on 316 L austenitic stainless steel test coupons were performed to validate the high level of confidence in the performance of a cyanide copper electrodeposited threaded insert. The validation tests results showed that cyanide copper electrodeposition for anti-seizing could be applied to the 316 L stainless steel threaded insert in the vacuum vessel and in-vessel components of the Tokamak fusion reactor.

Synergetic effect of graphene nanoplatelet, carbon fiber and coupling agent addition on the tribological, mechanical and thermal properties of polyamide 6,6 composites

Polyamide 6,6 (PA6,6) is one of the commonly used engineering polymers and it is used for various applications. Moreover, tribological and mechanical performance of PA6,6 can be improved with the addition of fibers or particulates. However, properties of reinforced PA6,6 matrix composites are affected by many factors. Interfacial adhesion between the reinforcement and matrix material is one of these factors and there should be good interfacial adhesion to obtain good ultimate properties. In this study, it was aimed to improve tribological and mechanical properties of carbon fiber reinforced PA6,6 composites by means of improving the fiber-matrix interaction by using graphene nanoplatelet (GNP) and 1,4-phenylene-bis-oxazoline (PBO). Adhesive wear test, tensile test, dynamic mechanical, differential scanning calorimetry and scanning electron microscopy analyses were performed. Consequently, all the test results manifested that CF_0.5GNP_PBO coded composites exhibited improved tribological and mechanical properties among the all composites.

Non-probabilistic reliability analysis and design optimization for valve-port plate pair of seawater hydraulic pump for underwater apparatus

Seawater hydraulic axial piston pumps are widely used in underwater apparatus systems in recent years. Reliability of the valve-port plate pair is vital to the performance of seawater hydraulic axial piston pumps. As the distribution information of the material combinations and working conditions of seawater hydraulic axial piston pumps are insufficient, the probability reliability analysis methods are not available for the valve-port plate pair. This paper develops a non-probabilistic reliability convex model for the valve-port plate pair. Firstly, the rotation of the pump cylinder is partitioned into six stages. Based on this partition, the dynamic models of contact pressure and pv value (the product of contact specific pressure and linear velocity) of the valve-port plate pair are derived by accounting for the pre-compression angle. Secondly, the marginal interval for the limiting [pv] value (It is the usual criterion to evaluate the critical operating conditions under which the material fails) of the material combination was obtained through adhesive wear tests. Thirdly, a limit-state function is then established based on the stress-strength interference model. Finally, the analysis and sea test results indicate that the reliability of the valve-port plate pair has significantly improved by adding auxiliary support on the port plate.

Effect of Phosphorus Addition on Dry Sliding Behavior of Fe–P Alloys Prepared by Powder Metallurgy

Iron–phosphorus powder metallurgy (P/M) alloys having 0, 0.35 and 0.65 wt.% P have been prepared by hot-forging technique. Hot forging consists of heating encapsulated powder at a temperature of 1050 °C in the atmosphere of hydrogen gas followed by hot forging. These hot-forged specimens have been subjected to dry sliding adhesive wear test at a normal load of 19.6, 29.4, and 39.2 N, at a constant sliding speed of 2.2 m/s and for a sliding distance of 4000 m using a pin-on-disk wear testing machine. Archard wear coefficient has been found to decrease from 2.5 × 10−7 to 1.4 × 10−7 with increasing phosphorus content in the alloys. The average coefficient of friction has also been found to decrease more or less linearly with increasing load as well as with increasing phosphorus content in the alloy. The mechanism of wear is primarily oxidative in nature, which has been confirmed by SEM–EDS analysis of the worn surfaces.