In this study, the potential of using metallurgical slags as alternative fillers in the development of automotive friction composites was investigated. Barite, blast furnace slag, copper slag and aluminum slag were preferred as fillers. A total of 13 samples, including a 40

In this study, micro and macro characterization of commercial brake pad by SEM, EDX, XRD and FTIR tests and determination of braking performance according to SAE J661 Test Procedure were aimed. The microstructure and spectrographic properties of the pad were compared with wear, density, surface roughness and hardness tests. In the study, it was determined that fibers, iron powders, oxides, vermiculite, graphite, barite and resin were homogeneously distributed in the microstructure and confirmed by the presence of :29 elements by EDX analysis. X-ray diffraction analysis revealed different morphologies and crystal forms in the test sample. The interaction of organic and inorganic compounds and functional groups of different elements were studied by FTIR analysis. In braking tests, the highest hot and cold coefficients of friction were 0.48 and 0.58, respectively, and the pad quality was determined as class G.

In this study, the modeling of the Pyrolytic oil production system using Artificial Neural Networks (ANNs) has been conducted with oak acorn, which can be considered as non-wood forest product. The parameters used in the pyrolytic oil production system have been determined as reactor temperature, nitrogen gas flow rate, biomass particle size, and heating rate. In experimental studies, the highest pyrolytic oil production has been achieved at 500 degrees C temperature, 1.5 L/min nitrogen gas flow rate, 5 degrees C/min heating rate, and 0-2 mm biomass particle size, with a product yield of 17.83%. 164 different Multi-Layer Feed Forward (MLFF) ANN-based network architectures have been trained for 20,000 iterations using the data obtained from the pyrolytic oil production system. In the training process, various network architectures including activation functionssuch as TanSig, LogSig, and RadBas with one or two hidden layers have been utilized. According to the results obtained from the studies, the Multi-Layer Feed Forward ANN-based Pyrolytic Oil Production System structure, which has a single hidden layer and contains 16 LogSig activation function neurons, has been the network structure with the best performance with the value of 1.08E-15.

The environmental impact of fossil fuels and their limited availability increase the need for research into alternative energy sources. In this research, pyrolysis oil (PO) was obtained from waste sour cherry kernels. PO cannot be used directly as fuel in diesel engines because of its negative fuel properties, such as low energy density, high viscosity, high water content, and low cetane number. Therefore, PO was blended with diesel at various weight proportions (wt%) using n-butanol (NB) as co-solvent, and 2-ethylhexyl nitrate (2-EHN) as cetane improver. Blended fuels containing 40 wt% diesel i.e., D2 (Diesel 40% / PO 0% / NB 55% / 2-EHN %5), D3 (Diesel 40 / PO 5% / NB 50% / 2-EHN 5%) and D4 (Diesel 40% / PO 15% / NB 40% / 2-EHN 5%) were identified as optimal blend compositions regarding the physicochemical characteristics of fuel. These fuels were tested for engine performance and emission characteristics at engine speeds of 1500, 1800, 2400, 3000 and 3600 rpm under full engine load (10 Nm) in a single-cylinder diesel engine. All data (i.e. cylinder pressure, engine torque and performance changes, heat release rate, and emission characteristics) were recorded using a Kistler KiBox data acquisition system. The engine tests showed a decrease in NOx, HC and soot emissions when blended fuels (D2, D3 and D4) were compared to D1 (Diesel 100% / PO0% / NB 0% / 2-EHN 0%). The lower NOx emissions in the blended fuels are explained by the PO's water content. Water raises the specific heat capacity of the fuel-air mixture while reducing the internal cylindertemperature. Additionally, the high latent heat of evaporation of n-butanol may contribute to reduce NOx emissions. In addition, the decrease in HC emissions may be caused by the increase in the oxygen ratio of blended fuels, while the decrease in soot emissions may be caused by the low C/H ratio and high oxygen content of blended fuels. To conclude, blends of PO, diesel n-butanol, and 2-EHN can be used as biofuels in diesel engine applications.

In this study, a fixed automotive friction material content was determined and the mechanical and tribological effects of manufacturing parameters on friction materials were investigated. Parameters; pre-forming time (1-3-5 min) and pre-forming pressure (8-10-12 MPa), hot pressing time (5-10-15 min) hot pressing pressure (8-10-12 MPa) and hot pressing temperature (125-150-175 °C), curing time (4-8-12 h) and curing temperature (120-150-180 °C) were determined. The friction test of the produced samples was carried out under 0.551 MPa pressure and 7 m/s rotation speed for 90 min. In addition, the average COF, friction stability, specific wear rate, density and hardness values of the samples were calculated. According to the results obtained, the average COF value increased as the pre-forming time and pressure increased. The lowest specific wear rate among all specimens was calculated as 7.622x10-6 cm3/Nm in PFP-12 specimen. With the increase in hot pressing time, the tribological properties of friction materials improved. The highest friction stability among all samples was calculated as 79.42% in the HPT-15 sample. Although there was an increase in the average COF value with increasing hot pressing pressure and temperature, the specific wear rates increased in these parameters. The highest average COF value among all samples was obtained in the CT-12 sample with a value of 0.553. The specific wear rate increased with the increase in curing time and temperature. The highest specific wear rate among all samples was calculated 10,743x10-6 cm3/Nm in the CTe-180 sample. Finally, it has been suggested that 3 min for pre-forming time, 12 MPa for pre-forming pressure; 15 min for hot pressing time, 12 MPa for hot pressing pressure, and 150°C for hot pressing temperature; and a curing time of 8 h and curing temperature of 150 °C may be sufficient.

Various international initiatives on environmental issues and the need to protect the environment are promoting the use of industrial waste in a variety of applications, including automotive brake pads. These studies show that the reuse of industrial waste can help to reduce the environmental impact. The development of environmentally friendly and cost-effective composites for use in a variety of engineering applications is the need of the century. The use of industrial waste in composite production is a possible solution for both problems. In this study, the potential use of talc, quartz and ceramic waste FFC fracture as a friction modifier in brake friction materials and its performance properties in accordance with industry requirements were investigated. The tribological, physical and mechanical properties of the brake pads were measured, and the friction surface morphology was investigated by scanning electron microscopy. According to the results obtained, the highest specific wear rate was observed in the FM3 sample. The FM2 sample with the highest hardness and average friction coefficient showed the lowest wear. FM4, FM5 and FM6 samples with high talc and quartz content exhibited low coefficient of friction characteristics compared to other samples.

In this study, the effect of sintering temperature on the physical, chemical and tribological effects of sintered automotive friction materials was investigated. Using the powder metallurgy method, 3 different samples were produced with the codes A1, A6 and A11. Mixing, pressing and sintering processes were applied respectively as production steps. Mixing time is 90 minutes, speed is 15 rpm. The pressing pressure is 250 MPa and the duration is 1 min. The sintering temperature was 800 °C and the sintering time was 1, 6 and 11 hours, respectively. The sintering process was carried out in the sintering mold using Argon gas. As the sintering time increased, it was observed that there was an increase in the time-dependent friction coefficients of the samples. Increasing the sintering time also increased the density of the samples. As the sintering time increased, the gap in the sample decreased, as it provided better bonding of the dustsers.

Şasi dinamometreleri motor, güç aktarma organları ve şasi bileşenlerinin test edilmesi amacıyla kullanılmaktadır. Taşıt tipi, boyutları ve ağırlığı gibi temel faktörlerin yanı sıra test cihazı yapısı, yazılımı ve ölçüm yöntemlerine göre sistem üzerinde farklı parametreler incelenebilmektedir. Test sistemi üzerinde kullanılan ekipman ve tasarım yapısına bağlı olarak ölçüm hassasiyeti değişmektedir. Günümüzde ikinci el araç kontrollerinde oto ekspertiz firmaları tarafından yaygın olarak gerçekleştirilen şasi dinamometre testlerinin doğruluğu ve güvenilirliği bir tartışma konusudur. Bu çalışmada, piyasada kullanılan şasi dinamometrelerinin ölçüm doğruluklarının araştırılması için üç farklı taşıt, iki farklı oto ekspertiz firmasında test edilmiştir. Testlerde common rail yakıt enjeksiyonuna sahip, turboşarjlı, Euro 5 emisyon normlarına uygun dizel motora ve manuel vites kutusuna sahip taşıtlar kullanılmıştır. Şasi dinamometrelerinde gerçekleştirilen tüm testlerde belirlenen standart adımlar izlenmiş olup testler basınç ve sıcaklık kaynaklı sapmaların önlenmesi için aynı lokasyondaki firmalarda gerçekleştirilmiştir. Test sonuçlarında taşıtlara ait maksimum güç ve maksimum güç devri, maksimum tork ve maksimum tork devri, ayrıca bu değerlerin fabrika verilerinden sapma miktarları elde edilmiştir. Firmalara ait test sonuçları kendi arasında ve fabrika verileri ile karşılaştırıldığında güç-tork eğrileri, maksimum güç-tork değerleri ve bu değerlerin ortaya çıktığı motor devirlerinde önemli ölçüde sapmalar oluştuğu tespit edilmiştir.

The purpose of this study is to investigate the air resistance effect of different side mir-ror models on automobiles. The Ahmed Body model with 250 slant angle is taken as ref-erence for use as automobile geometry. Ahmed body is a simplified geometry model used for aerodynamic analysis of land vehicles. Side mirror models with the same front projection area were modeled using Solidworks. CFD simulation was performed with ANSYS Fluent 19.2. Realizable k-ε model is used as turbulence model and pressure-based type is used as solver type. In this study, the mesh quality was checked in terms of skewness and showed conformity. CD value obtained by numerical analysis is compati-ble with experimental data. Then, a comparison was made by adding side mirrors to the Ahmed Body model. As a result of the analysis, the display of the velocity and pressure distribution caused by the change of form around the mirror models and total CD values were determined.

Bu çalışmada, piroliz yöntemiyle atık vişne çekirdeklerinden elde edilen pirolitik yağ (PY) fizikokimyasal olarak karakterize edildi. PY’nin fizikokimyasal yakıt özellikleri dizel ile kıyaslandığında yetersiz olduğu görüldü. Bu nedenle PY'nin dizel motorlarda alternatif bir yakıt olarak kullanılabilmesi için modifiye edilmesi gerekmekteydi. Yakıt özelliklerini iyileştirmek için PY’yi dizel ile karıştırmak iyi bir yaklaşım olabilirdi. Ancak PY dizel ile doğrudan homojen olarak karışmadı. PY'yi dizel ile homojen olarak karıştırmak için organik bir çözücü gerekliydi. Bu yüzden, n-bütanolü yardımcı bir çözücü olarak kullanarak çeşitli ağırlık oranlarında (ağırlıkça %) PY ile dizel karışımlarını başarılı bir şekilde hazırladık. Üçlü karışımların homojen olarak karışım sağlaya bilirliği, 48 saat sonra değerlendirildi. Sonuçlar, n-bütanol kullanılarak çok çeşitli kararlı homojen PY ve dizel karışımları yaratmanın mümkün olduğunu ortaya koyan üçlü faz diyagramında gösterildi. Karışım yakıtlar fizikokimyasal özellik yönünden PY'ye kıyasla artan kalorifik değer ve setan sayısı ve azalan kinematik viskozite, yoğunluk ve su içeriği gösterdi. Ancak setan sayısındaki artış dizele kıyasla optimum değerde olmadığı için karışımlara setan arttırıcı olarak 2-EthylhexylNitrate (2-EHN) ilave edildi. Böylece karışım yakıtların setan sayıları yaklaşık %84 oranında iyileştirildi. Sonuç olarak fizikokimyasal özellik yönünden ağırlıkça %40 dizel içeren (PY/Dizel/N-Bütanol/2-EHN) karışım yakıtların bir dizel motorunda alternatif bir yakıt olarak kullanılabileceği belirlendi.

Abstract Thermally sprayed WC-based coating systems are generally used to increase engineering components’ wear resistance. This research presents the results of a comparative study conducted to examine the tribological characteristics of a new brake disc created with thermal sprayed WC-10Co4Cr coating. This study implemented braking tests on the WC-10Co4Cr coated brake disc against commercial friction material on a laboratory scale disc-pad tester and compared the findings with the reference disc. The coating system was created with a high velocity oxygen-fuel spraying on a cast iron disc. The braking tests followed the sections of the SAE-J2430 test procedure. The microstructure, phase composition and properties of the coating were characterized by SEM/EDS, XRD and Vickers microstructure. The effect of carbide coating on the friction and wear behaviour of the tribological system was examined. The WC-10Co4Cr coating has increased the hardness by 3 times with a thickness of 300 μm compared to the cast iron surface. The amount of wear in the coated disc (CD) was reduced by about 85% compared to the reference disc (BD). The coefficient of frictions of BD and CD was found to be in the range of 0.43–0.61 and 0.47–0.62, respectively. The inclusion of hard phases (WC and W2C) in the disc coating played an important role in improving the sliding wear resistance by maintaining the coefficient of friction of the brake disc at an acceptable level. In brief, carbide coating could be claimed to be promising for challenging braking implementations.

Purpose The purpose of this study was to investigate the use of boric acid as a friction modifier material in brake friction composites and to determine the effect of heat treatment applied during production on braking performance. Design/methodology/approach The addition of five different amounts of boric acid was balanced with cashew, which is in the friction modifier material group. The samples were produced in the following order: dry mixing, preforming and hot-pressing. The effect of the heat treatment that can be applied after the hot-pressing process on the braking performance was investigated. The tribological and physical properties of the samples were determined using tests performed according to appropriate standards. The microstructures of the friction surfaces were investigated using scanning electron microscopy. Findings It was observed that the tribological properties of brake friction composites containing 20% by weight of boric acid were improved. It has also been observed that the heat treatment applied after hot pressing increased the friction coefficient of the samples by 7% on average and decreased the specific wear ratio of the samples. When the surface morphologies of the samples are examined, it is seen that the friction layers of the heat-treated samples are wider, and the microvoids and cracks are reduced. Originality/value This study showed that boric acid can be used as a friction modifier in brake friction composites. It also revealed the tribological and physical contribution of the applied heat treatment to the composite. Thus, it guides brake friction composite manufacturers in the industry and researchers working in this field.

In this study, the Taguchi optimisation technique was utilised to establish the composition of an asbestos-free brake pad. As a result of optimisation outputs, 18 various compositions were obtained. The produced specimens according to outputs were subjected to friction assessment and screening tests to evaluate their average friction coefficient and friction surface temperature. By assessing the results, the composition of brake pads, which can be used in vehicle brakes, was determined. The experimental results were also examined by variance analysis to demonstrate effect factors. Furthermore, when the test results were evaluated in terms of the friction coefficient, wear rate and temperature of the brake disc, a high coefficient of friction, a moderate wear rate and an acceptable temperature of the brake disc were obtained in sample 13. The composition of sample 13, which has the highest friction coefficient, is 3 g brass powder, 9 g cashew, 9 g carbon fibre, 9 g copper dust and 9 g graphite. Lastly, the average friction coefficients of brake pads were estimated through artificial neural network (ANN) analysis. With respect to the results, it was discovered that the generated ANN model promises a high ratio estimation capacity.

Switching from conventional fuels to alternative renewable biofuels offers the possibility of significant reductions in the pollutant emissions of diesel engines. Biofuel can be obtained from biomass through pyrolysis. Although pyrolysis oil (PO) is a suitable alternative biofuel for diesel engines, the direct use of PO in diesel engine is limited due to its insufficient properties. To improve the properties of PO, it can be blended with conventional diesel using n-butanol as a co-solvent. In this study, PO was produced from sour cherry kernels (SCPO) by pyrolysis at optimum operating conditions which were: 450 °C temperature, 0.5 L/min gas flow rate, 10 °C/min heating rate, 15 min residence time and particle size as broken kernels. SCPO was blended with diesel using n-butanol. The miscibility of the blends was assessed by evaluating their homogeneity after 48 hours. The physicochemical properties of SCPO and the blends were measured. Results showed that it was possible to create homogeneous blends of SCPO and diesel using n-butanol. Blends showed reduced density, kinematic viscosity and water content, and increased cetane number, pH and calorific value as compared to SCPO. We concluded that diesel/SCPO/n-butanol blends could be a potential biofuel source for diesel engine applications.

This study investigates surface fatigue damages by keeping fixed the material of test gear teeth, rotation speed, lubricating oil, and the applied load, and changing the operating temperatures of oil. In experimental studies, pre- and post-test weights of gear teeth samples were established, surface roughnesses were measured, and micrograph examinations were carried out on teeth surface. As a result, surface roughness and wear were established to increase in proportion to the rise in temperature of oil.

This paper investigates the use of rice straw powder in a brake pad as a substitute for asbestos which is a carcinogenic with detrimental effects on health. Rice straw powder was used as a novel material in a brake pad. Rice straw powder has a silica content which gives the pad a c eramic-like action. Rice straws were ground after drying in order to produce the powder. Five laboratory varieties were produced, altering the rice straw powder ingredients from 5, 10, 15, 20 and 25 wt.-%, respectively added to other abrasive materials, binder, friction modifiers, solid lubricant, and filler material utilizing conventional techniques. In this study, the friction surface temperature, the wear amount, and the change of the friction coefficient were determined. Additionally, the microstructure specifications of the brake pads were determined using scanning electron microscopy. Experimental results showed that a 15 wt.-% fraction of rice straw powder yielded better wear and thermo-mechanical features as compared with other combinations. The micro-structure shows a uniform distribution of the rice straw powder in the matrix. Hence, rice straw powder can be a possible candidate friction material for producing non-asbestos new brake pad without any detrimental impact.

This paper presents the findings of comparative research conducted to find out the braking performance of a Mo/NiCrBSi coated automobile brake disc. The friction and wear behavior of the Mo/NiCrBSi coating (CD) used for the disc material was evaluated using a laboratory scale disc-pad dynamometer and compared with a reference disc (RD). The coating was deposited by means of the atmospheric plasma spray process on a grey cast iron substrate. Braking tests were performed according to the SAE-J2430 test standard. Disc microstructures were characterized by SEM and XRD. It was found that the bonding strength was good with an infinite rating between the accumulated coating layer and the substrate. The results show that the coated brake disc has a comparable coefficient of friction and that the amount of wear is lower than that of the reference disc. The addition of ductile phases to the disc coating was beneficial in reducing the coefficient of friction to an acceptable degree and also effectively improving wear resistance.

The brake discs of the new generation vehicles operate with very high speed and tough braking conditions. Therefore, high performance in braking is essential in terms of human and vehicle safety. In vehicles, the braking performance criterion is to control the speed of the vehicle safely without causing a mechanical failure. During a braking process in a moving vehicle, an excessive abrasion occurs. The aim of this study was to investigate the performance of the brake disc coated with Cr2O3-2%TiO2 (Metco106F) composite powder by using the plasma coating method to increase the abrasion resistance of automobile brake disc. The braking test was performed according to the SAEJ2430 braking test standard. The microstructure, hardness, wear and braking performance characteristics of the coating were investigated. Our results showed that the coated disc exhibited better wear resistance than the uncoated disc under the different wear mechanisms at high temperatures. The obtained coefficient of friction revealed that the coated disc showed better braking performance.

In this study, 55TiO2-Cr2O3 (Metco111) ceramic powder was coated on cast iron disc by atmospheric plasma spraying (APS) coating method. The effect of coating on friction coefficient behavior according to SAE J2430 braking test standard was investigated. Mechanical and microstructural description of 55TiO2-Cr2O3 coating and uncoated disc was performed. Friction coefficient (COF) and wear rate decreased with growing temperature and speed. The coated and uncoated surfaces were analyzed by scanning electron microscopy (SEM), light microscope (LM)), with energy dispersive spectrometry (EDS). Surface roughness and micro hardness tests of samples were performed. Since Cr and Ti act as lubricant film with increased load and temperature in chromium and titanium-rich coatings, the friction coefficient and wear rate of the coating were lower than the uncoated disc. The lesser wear of the coated disc is ascribed to the rigid structure and lubricity of the surface film formed by the titanium and chromium oxides. Microstructure analysis revealed that the coating was metallurgically problem-free.

In this study, a single cylinder, four-stroke, naturally aspirated with compression ratio of 18:1 direct injection diesel engine was run with opium poppy oil biodiesel-diesel fuel blends. The effects of diesel and biodiesel-diesel fuel blends were investigated experimentally on combustion, performance and emissions. Experiments were conducted with standard diesel fuel and opium poppy oil biodiesel-diesel fuel blends (OP10 and OP20) at maximum brake torque speed of 2200 rpm and five different engine load including 25%, 50%, 75% and 100%. This study focuses on the detailed performance and combustion analysis with opium poppy biodiesel under different engine load and speeds. Test results showed that in-cylinder presssure and heat release rate increased with the increase of engine load when biodiesel fuel blends were used. ID period increased with the usage of biodiesel. Thermal efficiency decreased by about 5.73% and 13.05% with OP10 and OP20 compared to diesel respectively owing to lower calorific value of opium poppy oil biodiesel at 75% engine load. NOx increased 2.9% and 5.98% with OP10 and OP20 according to diesel at full load. On the contrary, CO decreased 14% and 17.42% with OP10 and OP20 compared to diesel at full load.