Tribological Studies of Brake Pad Materials: Effect of Contact Pressure, Sliding Speed, and Relative Humidity

A study on the friction and wear properties of brake pad materials under nominal contact pressure, sliding speed and relative humidity was carried out in order to understand the phenomena related to friction and wear processes at the contact surface of brake pad. Three LRT brake pads were employed and their compositions were examined using three x-ray techniques; (i) energy dispersive x-ray (EDX), (iii) x-ray fluorescence (XRF) and (iii) x-ray diffraction (XRD). The friction and wear studies were carried out using a three pins-on-disc apparatus over wide ranges of contact pressure, sliding speed and relative humidity. The worn surface morphology was examined by electron scanning microscopy and x-ray analysis. The results of friction curve analysis shows that friction took place by several stages and form six friction curve shapes, where each curve was influenced by the test parameters. The test parameters were also found influencing the duration of the friction stage. This phenomenon is affected by composition and thermal degradation of the samples. The appearance of friction curve shape also considered to be related to formation and destruction of friction layer process on the contact surface. X-Ray analysis of the friction layer at the mating surface indicated that the friction layer mostly consist of iron oxides. Wear of the sample show increasing wear with contact pressure and sliding speed. This factor is concluded due to increasing of plastic deformation, frictional heating and fatigue effect. Only wear of Pad-3 was found increase with relative humidity. This difference is considered affected by hardness, porosity and thermal degradation of the sample. Friction curve analysis and micrograph of wear debris indicated that wear process of the sample was taken place by three modes: (i) surface fracture, (ii) abrasion by wear debris and hard particles, and (iii) material transfer. The micrograph of the worn surface show that wear of the sample was taken place by combination of four mechanisms: (i) adhesion, (ii) abrasion, (iii) fatigue, and (iv) delaminatio

Tribological Study Of Jatropha Oil As Boundary Lubricant

Application of jatropha oil as boundary lubricant has been studied. In this research, boundary friction and wear preventive characteristics of jatropha oil as boundary lubricant were established. Structural modification and the use of selective additives were also studied to solve poor oxidation behavior of jatropha oil problem which could influence the oil performance as boundary lubricant. The main objectives of this research are: (i) to synthesize the derivatives of jatropha oil and establish their boundary friction, wear preventive, and thermo-oxidation properties, and (ii) to solve oxidative stability and wear preventive problem/issues of crude jatropha oil by the use of antioxidant additives and anti-wear additives. The friction and wear preventive properties were characterized by four-ball method. The thermo-oxidative behavior of the oil was studied by thermo-gravimetric analysis (TGA) and air bubbling oxidation methods. The modification of unsaturated carbon bond contained in crude jatropha oil (CJO) via epoxidation process was able to improve thermo-oxidative properties of jatropha oil. Epoxidized jatropha oil (EJO) show a higher first thermal degradation point of jatropha oil under oxidized condition compared to crude jatropha oil. It is also show significant reduction in the viscosity changes caused by high temperature obtained by air bubbling oxidation method. However, no significant effect to friction coefficient (μ), the value were μ CJO = 0.067 while μ EJO =0.065. But the epoxidized jatropha oil was found to show better wear preventive characteristics compared to jatropha oil, which average wear scar diameter of EJO is 0.581 mm while average wear scar diameter of CJO is 0.607 mm. The modification of unsaturated carbon bond via two stage esterification processes was not significantly able to improve the thermo-oxidative properties of jatropha oil. The first thermal degradation point of esterified fatty acid jatropha oil (EFA-JO) under oxidized condition was found lower than crude jatropha oil, although the viscosity changes caused by high temperature obtained by air bubbling oxidation method was significantly lower than jatropha oil. viii Friction coefficient of esterified fatty acid jatropha oil (EFA-JO) also show a higher value compared to crude jatropha oil (μEFA-JO = 0.075) and also show higher wear than crude jatropha oil (average wear scar diameter of EFA-JO is 0.779 mm). Addition of the octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate as an antioxidant additive was able to improved thermo-oxidative properties of jatropha oil. Addition 1-5 wt. % of this additive could raise the first thermal degradation point of jatropha oil under oxidized condition from 168°C up to 200°C. It is also show significant reduction in the viscosity changes caused by high temperature obtained by air bubbling oxidation method. Addition of tricresyl phosphate (TCP) as an anti-wear additive was significantly improved wear preventive capability of jatropha oil. Addition 1-5 wt. % of this additive to jatropha oil could reduce the average wear scar diameter of test the bearing from 0.607 mm up to 0.328 mm. Blend of tricresyl phosphate and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate also found able to improves friction, wear, and thermo-oxidative properties of crude jatropha oil. The study also found that the optimum blend, consisting of 3.59 wt.% of octadecyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 4.42 wt.% of tricresyl phosphate in crude jatropha oil, has friction coefficient of μ = 0.045 and average wear scar diameter of 0.324 mm. Further studies related to enhancement of boundary lubrication properties of jatropha oil such as structural modification or the use additives are highly recommended

Tribological Studies of Brake Pad Materials: Effect of Contact Pressure, Sliding Speed, and Relative Humidity

A study on the friction and wear properties of brake pad materials under nominal contact pressure, sliding speed and relative humidity was carried out in order to understand the phenomena related to friction and wear processes at the contact surface of brake pad. Three LRT brake pads were employed and their compositions were examined using three x-ray techniques; (i) energy dispersive x-ray (EDX), (iii) x-ray fluorescence (XRF) and (iii) x-ray diffraction (XRD). The friction and wear studies were carried out using a three pins-on-disc apparatus over wide ranges of contact pressure, sliding speed and relative humidity. The worn surface morphology was examined by electron scanning microscopy and x-ray analysis. The results of friction curve analysis shows that friction took place by several stages and form six friction curve shapes, where each curve was influenced by the test parameters. The test parameters were also found influencing the duration of the friction stage. This phenomenon is affected by composition and thermal degradation of the samples. The appearance of friction curve shape also considered to be related to formation and destruction of friction layer process on the contact surface. X-Ray analysis of the friction layer at the mating surface indicated that the friction layer mostly consist of iron oxides. Wear of the sample show increasing wear with contact pressure and sliding speed. This factor is concluded due to increasing of plastic deformation, frictional heating and fatigue effect. Only wear of Pad-3 was found increase with relative humidity. This difference is considered affected by hardness, porosity and thermal degradation of the sample. Friction curve analysis and micrograph of wear debris indicated that wear process of the sample was taken place by three modes: (i) surface fracture, (ii) abrasion by wear debris and hard particles, and (iii) material transfer. The micrograph of the worn surface show that wear of the sample was taken place by combination of four mechanisms: (i) adhesion, (ii) abrasion, (iii) fatigue, and (iv) delaminatio

TRIBOLOGICAL Sl1JDY OF JATROPHA (Jatropha carcass L) OIL AS ECO-FRIENDL Y BOUNDARY LUBRICANT

The prospect of jatropha oil as lubricant oil for boundary lubrication application is still not much studied yet. This research is mainly focused on enhancement of tribological properties ofjatropha oil as ceo-friendly lubricant base stock. The work is involving study on the effect of structural modification and additives addition to tribological properties of jatropha oil. The objectives of the research are: (i) to investigate friction, wear. and oxidation of jatropha oil, (ii) to synthesize and investigate friction, wear, and oxidation of jatropha oil derivatives, and (iii) to investigate the effects of anti-wear and antioxidant additives on friction, wear and oxidation of jatropha oil. Friction and wear preventive properties of the oil were examined by four ball method. Thermo-oxidative property of the oil was studied by thermo-gravimetric analysis (TGA) method. Fourier transform infra-red (FTIR) and nuclear magnetic resonance (NMR) were employed to study functional groups and stmcture changes in the jatropha oil

Pengaruh Penambahan Partikel Hexagonal Boron Nitride Dan Carbon Pada AA 7075 Melalui Proses Friction Stir Processing Terhadap Kekerasan Permukaan

Abstract:  reinforcement of AA 7075 material with nanoparticles may be developed. Therefore the authors wanted to conduct research on the effect of adding hexagonal boron nitride and coconut shell nano carbon particles to aluminum alloy 7075 through the friction stir processing (FSP) process on surface hardness and wear. Rpm to see a comparison of the speed of the mixture in aluminum, a mixture of hexagonal boron nitride particles and coconut shell nano carbon with the variants HBN25% : C75%, HBN50% : C50%, HBN75% : C25%. run the machine horizontally the process is repeated back and forth. The minimum hardness is 60.39 HRF 50% HBN material: C 50% rpm 2280, and the maximum hardness is 95.04 HRF 75% HBN material: C 25% rpm 2280. Pure 7075 aluminum is 90 HRF.Abstrak: Penguatan bahan AA 7075 dengan partikel nano melalui mungkin dapat dikembangkan. Oleh karena itu penulis ingin melakukan penelitian tentang pengaruh penambahan partikel hexagonal boron nitride dan nano carbon batok kelapa pada aluminium alloy 7075 melalui proses friction stir processing (fsp) terhadap kekerasan dan keausan permukaan.mesin fsp diatur speed dengan varian kecepatan 910, 1500, dan 2280 Rpm untuk melihat perbandingan dari speed terhadap campuran pada alumunium, campuran partikel hexagonal boron nitride dan nano Carbon batok kelapa dengan varian HBN25% : C75%, HBN50% : C50%, HBN75% : C25%. jalankan mesin secara horizontal proses diulang secara bolak balik.kekerasan minimum yaitu 60.39 HRF bahan HBN 50% : C 50% rpm 2280, dan kekerasan maksimum yaitu 95.04 HRF bahan HBN 75% : C 25% rpm2280. alumunium 7075 murni yaitu 90 HRF

Perancangan Alat Tribometer Pin On Cylinder Dan Aplikasinya Dalam Mengukur Keausan Kanvas Rem

Friction is a force that holds the movement of the shift or rotation of the two surfaces of the object. Friction that occurs continuously can cause wear. Measurement of wear rate is still done manually and difficulty getting the quality of lubricants. Then a test tool is needed to measure the rate of wear that is affordable and easy to use so that it is designed by a pin on cylinder. Pin on cylinder is a tool to measure the rate of wear and can test the quality of lubricants in anticipating wear. Pin on cylinder applies a leverage where the load applied at the end of a lever can be folded by its force at the other end. The loading force that has been multiplied will be focused on a specimen that is pressed to the rotating cylinder. This test tool is designed to test the wear between two objects that rub against a pressure of 10 kg where the rotor will rotate at a constant speed when the load is applied. Dimension design and basic form of this test tool uses Solidworks design software. Cylinder axis is made from S45C engine construction steel for load planning up to 300 N. Cylinder surface is designed to use Chromium Stainles Steel material. The specimens used are brake lining. The test was carried out three times using the load and speed variable. The test results that have been carried out with the rate of wear of the specimen using the lost load variable show a significant difference in the same period of testing. PIN test equipment on cylinder 10 kg loading capacity can operate according to the design

Effect Of SiC/Fly Ash Reinforcement On Surface Properties Of Aluminum 7075 Hybrid Composites

Friction stir processing (FSP) has emerged as a valuable technique in the surface metal matrix composite fabrication field. In this process, solid-state processing mostly avoids the formation of detrimental phases inside composites. Despite having a high specific strength, further extensive Al alloy applications are limited due to their poor surface properties. A hybrid reinforcement approach can be used to improve surface properties. In this study, industrial waste fly ash material is mixed with hard SiC ceramic particles. The main focus of this research is to improve wear resistance under dry sliding conditions and microhardness of aluminum 7075-T651 by dispersion of silicon carbide-fly ash (SiC/fly ash) powder in a base alloy by FSP. The parameters used for this investigation are: tool rotation rpm (500, 1000 and 1500), the tool traverse mm/min (20, 30 and 40), the reinforcement's hybrid ratio HR (60:40, 75:25 and 90:10) and the volume percentage vol.% (4%, 8% and 12%). The influence of these parameters on the resultant composite's microstructure, dry sliding wear rate and micro-hardness was studied. By using response surface methodology (RSM), desirable ranges of process parameters for lower wear rate and higher microhardness were obtained. The interaction effect of SiC/fly ash volume percentage and hybrid ratio had the most influential effect on the wear rates, as well as microhardness of composites. Moreover, microhardness increased with an increase in the volume percentage of SiC/fly ash powders towards high SiC content in hybrid ratio. Interestingly, among stirring parameters, tool traverse speed was found to be more influential than tool rotational speed. The minimum wear rate was observed for the Run 20 sample (w: 1000 rpm, v: 40 mm/min, HR: 75:25, vol.%: 8). A maximum microhardness of 241.20 HV was achieved for Run 15 (w: 500 rpm, v: 40 mm/min, HR: 90:10, vol.%: 12) sample. Mainly, reinforcement distribution-in accordance with the stirring action generated by the tool-had a major role in controlling the surface properties of the resultant composites

Mechanical properties of oil palm frond wood filled thermoplastic polyurethane

The problem of the biomass waste produced from palm oil plantation is present today. The biomass waste typically is sourced from oil palm trunk (OPT), oil palm frond (OPF) and oil palm fruit bunch. Considering the huge amounts OPF wood waste from palm oil plantation, the waste can have other added value if they can be used as in polymer composite materials. This study is subjected to investigate the effect of oil palm frond (OPF) fiber and powder loading to hardness, toughness, tensile and flexural strength of thermoplastic polyurethane (TPU) as wood polymer composite. Frond fiber with size of 2-3 mm and frond powder with size of 60-90 micron were used as filler materials. The TPU/OPF composite samples were fabricated by compressive molding approach. The result shows that hardness of TPU based composite increased by 48% with the addition of 30 wt.% of OPF powder. Ultimate tensile strength of TPU increased by 26% with addition of 30 wt.% OPF frond powder. The impact strength of TPU increased by about 50 % by the addition of 30 wt.% of OPF frond fiber, while the flexural strength of TPU/OPF composites increased by about 86% by the addition of 30% OPF frond fiber. The microstructure of TPU/OPF composite samples shows good interfacial bonding between TPU matrix to OPF powder and OPF fiber, which represents a significant improvement of mechanical properties of TPU/OPF composites. It can be concluded that both, OPF powder and fiber addition significantly improved the mechanical properties of TPU. The OPF powder improved hardness and tensile strength, while the OPF fiber improved on the impact and flexural strength of the TP

Investigation On Oxidation And Thermal Stability Of Jatropha Oil

The application of jatropha oil as alternative lubricant basestock has emerged recently. However, the resistance to oxidation and thermal stability of this oil become a concern to its application as lubricant. In this study, the oxidation and thermal degradation of crude jatropha oil (CJO) have been studied. The oxidation of the CJO was investigated by air bubbling method. The viscosity and functional group changes due to oxidation were studied before and after oxidation test. The thermal stability of CJO was investigated by using Thermogravimetric analysis (TGA) method in O2 and N2 gases environment. Jatropha oil was found oxidized by autoxidation mechanism produces high molecular species which capable to increase viscosity of the oil. The TGA results shows that CJO thermally stable in the temperature below 168°C in O2 gas environment and below 225°C in N2 gas environment