Wear Of Engine Components Research Articles

Tribological and Mechanical Behavior of Automotive Crankshaft Steel Superficially Modified Using the Boriding Hardening Process

One of the primary challenges in the automotive industry is the wear of engine components, such as the crankshaft and camshaft, which is the most pronounced during the engine’s startup phase, when the amount of lubricant fluid is at its lowest. This study aims to enhance the surface wear resistance of automotive crankshaft steel by applying a boriding thermochemical process. This process forms a hard surface layer on the steel, improving its mechanical properties and bolstering its wear resistance, especially under dry conditions. Boride layers were achieved using the powder-pack boriding process in a conventional furnace, with meticulous treatment times of 2, 4, and 6 h at a constant temperature of 950 °C. The nature of the layers was analyzed using X-ray diffraction, and their tribological behavior was evaluated using the pin-on-disk test. The growth of the layers was directly proportional to the treatment time and was estimated at 145 µm and 48 µm for the 6 and 2 h of treatment, respectively. The surface hardness increased from 320 HV for the non-treated steel to 2034 HV for the sample exposed to 950 °C for 6 h. The results indicate a significant reduction in the coefficient of friction from 0.43 for the non-treated steel to 0.12 for the samples exposed to 950 °C for 6 h, suggesting potential wear protection during the engine starting period.

WEAR RESISTANCE OF STELLITE 6 COATINGS AT HIGH TEMPERATURE

Stellite 6 is a superalloy primarily composed of cobalt, known for its exceptional resistance to corrosion and wear at elevated temperatures. The current investigation involved the application of a co-based Stellite 6 coating on SS 304 boiler heat exchanger steel using HVOF technology. The objective was to boost surface wear resistance against elevated temperature. Protective coatings are widely employed across various industries to enhance resistance to erosion and wear of engineering components. The corrosion behavior of coated and uncoated steel was assessed under various conditions, including impact velocity, impact angle, and time duration, using a high-temperature air-jet erosion tester. Microploughing, cracking cutting, and hard phase pull-outs were all erosion processes seen in the coatings. Among the samples that were tested, it was observed that the Stellite 6 coating applied on SS 304 exhibited the lowest erosion rate. This study aims to facilitate the selection and optimization of coating materials suitable for applications in industry that require enhanced resistance against erosion wear under high-temperature conditions.

Predictive Neural Network Modeling for Diesel Engine Part Wear Assessment via Analysis of Wear Element Concentration in Used Oil

Used oil serves as a repository of wear elements, reflective of the friction generated among various engine components. The accumulation of these elements offers vital insights for understanding wear and tear in diesel engine parts. Accurate prediction of such wear is imperative for strategic maintenance planning and cost efficiency.
 This paper presents an innovative methodology that leverages artificial neural network modeling to forecast the degradation of locomotive diesel engine components based on the concentrations of wear elements in used oil and the corresponding vehicle mileage. The proposed supervised artificial neural network comprises two hierarchical architectures: one linking diesel locomotive operation and wear element concentration, and another associating diesel locomotive operation with diesel engine component wear. Through experimental validation, the results highlight the efficacy of the developed neural network model in precisely estimating the wear of diesel engine components. This predictive capability empowers informed maintenance decision-making to bolster engine reliability and performance.

Experimental Investigation of Possibilities to Improve Filtration Efficiency of Tangential Inlet Return Cyclones by Modification of Their Design

It has been shown that tangential inlet return cyclones are commonly used for inlet air filtration of off-road vehicle engines. The wear of the engine elements, and thus their durability, is determined by the efficiency and accuracy of the inlet air filtration. It has been shown that the possibilities of increasing the separation efficiency or decreasing the pressure drop of a cyclone by changing the main dimensions of the cyclone are limited, because any arbitrary change in one of the dimensions of an already operating cyclone may cause the opposite effect. A literature analysis of the possibility of increasing the filtration efficiency of cyclones by modifying the design of selected cyclone components was conducted. In this paper, three modifications of the cyclone design with a tangential inlet of the inlet air filter of a military tracked vehicle were proposed and performed. The symmetrical inlet of the cyclone was replaced with an asymmetrical inlet. The cylindrical outlet tube was replaced with a conical tube, and the edges of the inlet opening were given an additional streamlined shape. The modification process was carried out on three specimens of the reversible cyclone with a tangential inlet. After each modification, an experimental evaluation of the modifications was carried out. The influence of the modifications on the cyclone’s efficiency characteristics and pressure drop was examined. Subsequent modifications of the cyclone were performed on the same specimen without removing the previous modifications. Tests were performed in the air flow range QG = 5–30 m3/h. Polydisperse “fine” test dust with grain size dpmax = 80 µm was used for testing. The dust concentration at the cyclone inlet was set at 1 g/m2. The performed modifications caused a slight (about 1%) increase in separation efficiency in the range of small (up to QG = 22 m3/h) flux values and about 30% decrease in pressure drop in the whole range of the QG flux, which positively influences the increase in engine filling and its power. There was a noticeable increase in filtration accuracy in the range of low and high values of QG flux, which results in a decrease in the wear of engine components, especially the piston-piston ring-cylinder (P-PR-C) association, and an increase in their durability.

CFD Analysis of the Effect of Dimples and Cylinder Liner Honing Groove on the Tribological Characteristics of a Low Displacement Engine

The contact between the piston rings and the cylinder liner is an interface with a strong influence on the tribological behavior and, therefore, directly affects the useful life of the engine components and fuel consumption. Due to this importance, the present investigation carried out an analysis of the effects of dimples and the honing groove in the cylinder liner on the tribological characteristics. A tribological model was developed to study the friction forces, minimum film thickness, and friction coefficient for the present investigation. Similarly, a computational fluid dynamics model was built to determine the dynamic movement of the piston. The validation of the numerical model showed a close similarity with the real behavior of the engine, obtaining an average relative error of 14%. The analysis of the results showed that a 3% increase in dimples’ density leads to a 3.79% increase in the minimum lubricant film and a 2.76% decrease in friction force. Additionally, it was shown that doubling the radius and depth of the dimple produces an increase of 3.86% and 1.91% in the thickness of the lubrication film. The most suitable distribution of the dimples on the surface of the cylinder liner corresponds to a square array. In general, the application of dimples and honing grooves in the cylinder liner are promising alternatives to reduce energy losses and minimize wear of engine components.

Effect of Diesel-Palm Fatty Acid Distillate Ethyl Ester-Hydrous Ethanol Blend on the Performance, Emissions, and Long-Term Endurance Test on an Unmodified DI Diesel Engine.

In this research, the diesel–palm fatty acid distillate ethyl ester–hydrous ethanol, palm fatty acid distillate ethyl ester, and diesel were studied to investigate the gas emissions and performances of the direct injection diesel engine at different engine loads and engine speeds. At all engine speeds and loads, nitrogen oxide emissions from all fuel blends (D50PE40E10, D40PE50E10, and D30PE60E10) were significantly lower than the baseline diesel. At all engine speeds and engine loads, the fuel blends released less carbon dioxide than the baseline diesel, with the exception of the D30PE60E10 blend. Furthermore, D30PE60E10 diesel was used to test wear for 500 h long-term endurance of diesel engine components. The results indicated that biodiesel in fuel blends may reduce engine component wear by forming a thin coating on the metal surface of the engine component. However, after 100 h of continuous operation with D30PE60E10 blend, the engine cannot be restarted because only a part of the fuel pump had many pores on the surface of the plunger, barrel, delivery valve, and valve holder. However, these components may have to be considered to prevent corrosion when this fuel blend was employed.

A Study on the Effect of Inlet Air Pollution on the Engine Component Wear and Operation

This paper systematically reviews the research progress in the field of the influence of air pollutants in the engine inlet on the accelerated wear of the elements of the association: piston, piston rings, cylinder liner (P-PR-CL), and plain bearing (journal–panel). It was shown at the outset that the primary component of air pollution is road dust. Its main components are dust grains of hard minerals (SiO2, Al2O3), which penetrate the oil film area between two frictionally mating surfaces causing their abrasive wear. Therefore, the effect of three dust parameters (grain size and hardness, and dust concentration in air) on the accelerated wear of the friction pair: piston, piston rings, cylinder liner(P-PR-CL), and plain bearing (journal–pan) is presented extensively. It was noted that the wear values of the same component were obtained by different researchers using different testing techniques and evaluated by different indices. It has been shown that the greatest wear of two frictionally cooperating surfaces is caused by dust grains with sizes equal to the thickness of the oil film at a given moment, which in typical combustion engine associations assumes varied and variable values in the range of 0–50 µm. The oil film thickness between the upper ring and the cylinder liner varies and depends on the crankshaft rotation angle, engine speed and load, and oil viscosity, and takes values less than 10 µm. It was shown that the maximum wear of the cylinder liner, resulting from the cooperation with the piston rings, occurs in the top dead centre (TDC) area and results from unfavorable (high temperature, low piston speed) operating conditions of these elements. From the extensive literature data cited, it follows that abrasive wear is caused by dust grains of specific dimensions, most often 5–20 µm, the greater the wear the greater the hardness of the grains and the sulfur content of the fuel. At the same time, it was shown that the main bearing, crankshaft bearing, and oil ring experienced maximum wear by a different range of particle size, respectively: 20–40, 5–10, and 20–80 μm. It was shown that the mass of dust that enters the engine cylinders and thus the wear of the components is determined by the concentration of dust, the value of which is definitely reduced by the air filter. However, it was pointed out that the low initial filtration efficiency and the presence of large dust grains in the purified air in the initial period of the filter operation (after replacement of the filter element with a new one) may have an impact on the accelerated wear of mainly (P-PR-CL) association. The next stage of the paper presents the effects of excessive wear of the cylinder liner and piston rings of the engine, resulting from actual vehicle operation and bench tests on the decrease in compression pressure and engine power, increase in the intensity of exhaust gas blow-by into the oil sump and increase in oil consumption and exhaust gas toxicity. This paper addresses the current problem of the effect of engine inlet air contaminants on the performance of the air flow meter, which is an essential sensor of the modern internal combustion engine. The phenomenon of deposition of contaminants (mineral dust, salt, carbon deposit, and moisture) on the measuring element (wire or layer anemometer) of the air flow meter has been analyzed. The empirical results presented show that the mineral dust layer on the measuring element of the air flow meter causes a 17.9% reduction in output voltage, and the dust and oil layer causes a 46.7% reduction in output voltage. This affects the decrease in engine power and exhaust toxicity.

Otkrivanje mogućih oštećenja motora u slučaju vojnih vozila sa kontinualnim kolosekom sa tribološkim istraživanjima

Detecting the engine failures of the continuous track military vehicles is challenging because their engines are always built-in narrow places covered with armored plates. In the case of the older engines, modern computer diagnostics cannot be used for failure analysis; the solution for these tasks is the visual analysis with the engine disassembly. A possible cost-effective failure analysis method can be the tribological and chemical analysis of the used oil from the engine, which can eliminate the engine disassembly work and as the results of the chemical oil analysis can also provide information about possible fuel or cooling water dilution or the increased wear of engine components. The main goal of this article is to present the failure analysis method through the tribological investigation of the engines of two PTSZ-M type medium-tracked amphibious military transport vehicles.

Contamination of the intake air of internal combustion engines of motor vehicles

The paper presents the composition of atmospheric air as a mixture of gases that make up the solid and variable components, and the definitions of air pollutants are referenced. Gaseous and solid pollutants (dust) of the atmospheric air have been defined. Dusts were divided according to various criteria and their properties were given. Exemplary courses of immission of the fraction of solid particles are given, indicating a strong dependence of the immission on the seasons, days of the week and day and night. The sources and characteristics of artificial and natural pollutants in the atmospheric air are presented. It has been shown that the main sources of anthropogenic pollution in addition to industry and the automotive industry. Cars are a source of gaseous and particulate pollutants PM, and they also emit pollution from brake and clutch lining wear, as well as from tire and road wear. The main sources of natural air pollution were discussed, including volcanic eruptions, fires in landfills, forests, steppes and sand storms, as well as mineral dust (road dust) carried from the ground by vehicles. The properties of road dust are discussed: chemical and fractional composition, density, dust concentration in the air. It has been shown that the two basic components of the dust, silica and corundum, whose share in dust reaches 95%, also have the highest hardness, which may have a decisive influence on the wear of engine components. Various valuesof dust concentration in the air were presented depending on the type and condition of the ground and the conditions of use of vehicles. Keywords: mechanical engineering, internal combustion engines, air pollution sources, road dust

Chemical and physical assessment of engine oils degradation and additive depletion by soot

Soot contamination in engine oil causes a significant increase in wear of engine components. Presence of soot in the engine oil is one of the most common reasons leading to an increase in oil change intervals. There are several mechanisms that affect the performance of engine oil such as oil degradation, additive decomposition and additive adsorption on soot particles. It is recommended that removal of soot contamination from engine oil can reduce wear of engine components and extend the service life of engine oil. However, removing soot particles from the engine oil can diminish the efficiency of additives in engine oils as some additives adsorbs on these particles. There is still no census on this area. Thus, this experimental study aims to investigate how removing different levels of Carbon Black Particles (CBP), commonly used as surrogate for soot, from aged engine oil influences the engine oil performance. The study reveals three main mechanisms that influence the tribological performance of the engine oil expressed as additive depletion, additive adsorption and degradation products. Removal of CBP from engine oil is expected to reclaim the oil performance. However, the results demonstrate that the performance of oil after removal of CBP is still not as good as the fresh oil. These results confirms that reclaiming the oil performance can not be achieved by just removing the CBP. Other mechanisms such as oil degradation and additive adsorption on CBP adversely affect the engine oil performance during the removal of CBP.

Airborne particles in city bus: concentrations, sources and simulated pulmonary solubility.

PM10 and PM2.5 concentrations in Ljubljana city bus were monitored during entire shift, and individual particles were morphologically and chemically characterised in order to determine PM concentration variability, particle sources, solubility in simulated pulmonary environment and effects on human health. PM measurements revealed high mean PM10 (82.8μg/m3) and PM2.5 (47μg/m3), which were highest and most variable during rush hours with fluid traffic and lowest during traffic jams with standing vehicles. Individual particle analysis showed that airborne particles were dominated by metal-bearing phases, particularly small-sized (Cr,Mn,Zn)-bearing Fe-oxyhydroxides and Al-/Fe-Al-oxides, large (Fe,Cr,Ni)- and (Cu,Zn,Ni)-alloys, and small-sized Sb-sulphide and Ba-sulphate. Non-metallic phases were represented by (Ca,Mg)-carbonates, Al-silicates, Na-chloride and Ca-sulphate. Comparison with possible source materials (vehicle exhaust emissions, brake disc dust and road sediment) showed that primary sources of these metal-bearing phases were wear of brake discs, brake pads and tyres, and also wear of engine components and catalytic converters. Most non-metallic phases originated from resuspension of road sediment, containing road sanding materials, but also from emissions of burned fuel and lubricating oil (Ca-sulphate). Assessment of effects on human health indicated that mean PM concentrations, which significantly exceeded daily limit values, increased mortality (by 2-3%) and morbidity (by 7-8%) risk for bus drivers. Simplified PHREEQC calculations of airborne metal-bearing phase solubility in aqueous solutions simulating pulmonary environment showed that metallic Fe, Ba-sulphate, Sb-sulphide and Al-oxide, partly also Cu-bearing metal alloys, were soluble under reducing and oxidising conditions, but released metals were removed from solution by precipitation of stable secondary metal-bearing phases.

Experimental Study of Filtration Materials Used in the Car Air Intake.

Traditional cellulose filter media used for air filtration in vehicle engines are characterized by 99.9% filtration efficiency and accuracy above 2–5 µm. The highest engine component wear is caused by dust grains above 1 µm. Filter media with nanofiber additions provide greater filtration efficiency of dust grains below 5 µm. Filter material selection for vehicle engine air filter is a problem because their manufacturers mainly provide only the structure parameters: pore size, air permeability, and thickness. There is no information about material filtration properties using polydisperse test dust. The manuscript presents methodology and experimental test results of five samples A, B, C, D and E, filter materials differing in their chemical composition and structure parameters. In the first stage, efficiency characteristics φw, filtration accuracy dzmax and the flow resistance Δpw depending on the dust absorption coefficient km of three filter cartridges of each material, A, B, C, D and E, were determined. Then, from each material characteristics of one piece was selected in order to compare their initial and initial period efficiencies as well as changes in the flow resistance depending on the dust absorption coefficient km. Obtained results showed that the filter materials differ significantly in efficiency and accuracy values in the initial filtration period. Initial period duration is also different, i.e., filtration efficiency increasing time to a certain value, which for materials with a nanofiber layer is much shorter, which minimizes engine component wear. For materials with nanofibers, flow resistance increase intensity is greater, which results from surface filtration. Filtration efficiency of each filter material sample A, B, C, D and E was assessed with the filtration quality coefficient including the efficiency and flow resistance. In the available literature, the problem of increasing filtration efficiency in the initial period is known, but there are no results for specific filter materials. Research shows that filter material characteristics are closely related. Each increase in efficiency and accuracy of intake air filtration reduces engine components wear, but it is related to flow resistance increase in the engine intake system, which reduces its power, and increases need for more frequent filter servicing.

Effects of hexagonal boron nitride based nanofluid on the tribological and performance, emission characteristics of a diesel engine: An experimental study

AbstractIn recent years, nanoparticles have attracted researchers attention due to its wear and friction reduction characteristics in lubricating oil. Hence, it is of utmost importance to consider nanoparticles additive in the lube oil and study its impact on the tribological and performance characteristics of mechanical systems. Therefore, this paper intends to explore the impact of conventional and hexagonal boron nitride (hBN) nanoparticles‐based lubricant on the wear of engine components, performance, and emission characteristics of a diesel engine. The different concentration namely, 0.5 wt.%, 0.75 wt.%, and 1 wt.% BN‐based nanofluids were formulated. The formulated nanofluids were characterized by UV‐spectroscopy and differential scanning calorimetry (DSC) for dispersion and heat capacity analyses respectively. From the characterization results, 1wt.% BN nanofluid was found stable and well dispersed and therefore, considered for further experimental analysis. The outcomes of the present study revealed that 1 wt.% BN‐based nanofluid shown better anti‐wear properties and improvement in performance, emission characteristics of the diesel engine. The obtained results will be useful for the lubricant industry to think toward formulating nanoparticles‐based lubricating oil.

Unapređenje metoda vibro-akustične kontrole mehanizma za distribuciju gasa kod SUS motora

A modern vehicle is a system of high-precision systems. In particular, over the past 20 years, the gas distribution mechanism (GRM) has been structurally released from any adjustments. However, alongside with that, the elimination of the adjustments did not entail a decrease in the number of GDM failures. The analysis of a number of works shows that the GDM mechanism accounts for more than 30% of ICE failures. The problem lies in the high sensitivity of modern engine systems to the oil drain interval, fuel quality, timeliness of maintenance, etc., i.e. to carrying out of routine activities. According to the analysis of the operating conditions of modern vehicles, the regulations are significantly violated in more than 50% of cases, which results is a considerable reduction in the service life of vehicles. In this connection, it is relevant to develop diagnostic methods allowing us to determine the degree of wear of engine components at all vehicle operation stages. One of such methods is the vibro-acoustic method. The research aims to develop a methodology and method for diagnosing GRM by analyzing vibration parameters together with a pressure signal in the cylinder, the angle of the ICE crankshaft. As a result, the mechanism for recognizing the fault conditions of individual GRM valves is determined. A set of diagnostic tools for the selective diagnosis of GRM elements has been developed. A methodology for determining the GRM phases and thermal clearances in the valve drive using the nondemountable method has been created.

Numerical minimisation of abrasive-dust wear in internal combustion engines

This paper presents a mathematical model to predict the abrasive wear of piston ring and cylinder sleeve in internal combustion engines due to dust particles. A parametric study is conducted on different group factors such as the abrasive action of the medium, engine design parameters, and engine physio-mechanical properties of the materials. The model reveals that it accurately predicts the effect of numerous factors on the wear process for the piston ring and cylinder sleeve. The model capabilities are demonstrated by the impact of air filtration efficiency on the engine component wear rate. It is found that dust particle size and concentration have significant effects on piston ring and cylinder sleeve wear rates. The numerical results show that the wear rate of both the piston ring and cylinder sleeve can be reduced by 80% when the air filter efficiency is increased from 97.8% to 99.4%.

Investigation of tribological properties and engine performance of polyol ester–based bio-lubricant: Commercial motorbike engine oil blends

This article explores the influence of blending polyol ester–based bio-lubricant with commercial lubricant on engine performance. Polyol esters trimethylolpropane ester and pentaerythritol ester were prepared from Calophyllum inophyllum seeds. Extreme care was taken to minimize deterioration of physicochemical properties when blending bio-lubricant with commercial oil. Blending of bio-lubricant with commercial oil was carried out in 10%, 15%, 20% and 25% volume. The test oils were first investigated for wear and friction properties on a four-ball wear tester. Optimum blending ratio was calculated from results of tribological properties, and the blend with optimum blend ratio was investigated for engine performance. The engine performance of the optimum blends was evaluated by conducting a 60-h endurance test on a motorbike. Significant improvement in tribological properties was observed up to a blending percentage of 15% when blending pentaerythritol ester with commercial oil. In the case of trimethylolpropane ester–based bio-lubricant, 10% blending with commercial oil gave optimum performance. The novel evaluation of engine performance of commercial oil and blends has shown a reduction in the wear of engine components with an encouraging decrease in fuel consumption. Metallographic studies conducted on worn piston rings reveal synergy between additives in the commercial oil and esters in the bio-lubricant in reducing wear and friction, thereby reducing fuel consumption.

Topsoil pollution in highway medians in the State of São Paulo (Brazil): determination of potentially toxic elements using synchrotron radiation total reflection X-ray fluorescence.

The presence of metals in vehicle emissions is due to several factors, such as the composition of fuels and lubricating oils, the wear of engine components, and their use in catalytic converters. It is known that the soil near highways is greatly affected by heavy vehicle traffic, since the use of highways is of fundamental importance for the flow of goods and public transport, especially in Brazil, street transport being the main form of transport in the country. Considering the scenario described, the main objective of this study was to monitor the concentration of potentially toxic elements in surface soils located on the medians of the main access highways in the city of Campinas (SP-Brazil) and classify the soils through geoaccumulation index. Using SR-TXRF it was possible to detect and determine the concentrations of 5 elements of toxic-environmental interest (Cr, Ni, Cu, Zn, and Pb) and 11 natural soil composition elements (Al, Si, S, Cl, K, Ca, Ti, Mn, Fe, Rb, and Sr). To evaluate the influence of highway distance on elementary concentrations, ANOVA and Tukey statistical tests were applied. Nickel, Cu, and Zn showed a decrease in their concentrations moving away from the highway, indicating their relation with vehicular emissions. Applying principal components analysis (PCA), it was possible to identify four groups of the quantified elements: those mainly related to the soil itself, those produced by traffic of automotive vehicles, and those emitted by industrial activities.

Zinc Dialkyldithiophosphate Additive Adsorption on Carbon Black Particles

Soot is known to cause high wear in engine components and this is a problem with engine oils between extended drain intervals. Although several wear mechanisms have been suggested, exact soot-induced wear mechanisms are still not fully understood. This study aims to investigate the additive adsorption mechanism (specifically anti-wear additive) on carbon black (CB) particles (as a soot surrogate). This mechanism is one of the main mechanisms responsible for high wear. Base oil (BO) was used to exclude the effect of other additives that are present in fully formulated oil. Zinc dialkyldithiophosphate (ZDDP) anti-wear additive was added to the BO and then the mixture, which will be referred to as the model oil, was aged with CB particles. The resulting oils were then chemically characterised by using ICP and FTIR analysis techniques. Finally, the CB particles were filtered out and analysed using EDX. The results showed that both zinc and phosphorous which are chemical elements from ZDDP anti-wear additive were adsorbed on CB particles in the oil phase. This additive adsorption mechanism can lead to increased wear in the engine components due to lack of additives in the oil. This study highlights the importance of understanding the additive adsorption on soot particles since this mechanism will reduce the engine oil life and increase frequency of oil changes.

Study on tribological behavior of biodiesel – Diethyl ether (B20A4) blend for long run test on compression ignition engine

The gradual reduction of world petroleum reserves, growths in prices of petroleum-based fuels and environmental pollution has increased attention to the search for unconventional fuels such as biodiesel. It has remained the focus of extensive amount of research since it is renewable and reduces the emission of pollutants. Though, some of the significant issues like compatibility of biodiesel with the crankcase lube oil, thermal stability of lube oil with biodiesel, changes in physical and chemical properties of lubricating oil with biodiesel etc. have not been adequately inspected. These requirements are to be addressed in order to confirm the long-term suitability of biodiesel in a current family of diesel engines. In the present work, these problems are addressed. With an overall objective of life cycle analysis, a long run endurance test (512 h) is carried out on CI engines fuelled with diesel and the optimized blend of bio-diesel fuel (B20A4) respectively. The endurance tests are directed as per IS 10,000 for the examination of wear of engine components, lubricant's properties, suspended impurities, and wear metal debris. The wear of the various component of the engine is characterized by dimension and weight measurements. Lube oil analysis (Atomic Absorption Spectroscopy – AAS, Ferrography) were performed on oil samples, taken after every 128 h. The oil analysis suggested that the wear of B20A4 fuelled engine is substantially lower compared to the diesel. A regression model was also proposed to predict wear of the engine. The proposed regression model can be taken one step further to predict the overall wear of the engine. The total concentration of various metals debris collected in the lube oil sample (predicted using regression model) was found to be 640 mg/kg and 420 mg/kg for diesel and B20A4 respectively.

Metallurgical and Tribological Evaluation of Fe-Cr-C Hardfacing Alloys

Raw material handling areas in an integrated steel plant experience severe wear of engineering components. The use of hardfacing plates is one of the ways to combat this problem. Three commercial hardfacing Fe-Cr-C alloys of varying Cr content were deposited on mild steel base plate and studied in this work. Abrasive wear tests were conducted by using pin-on-disk tribometer in accordance with the ASTM G99. Microstructural characterization was done by using optical and scanning electron microscopes. Energy- and wavelength-dispersive spectroscopies were carried out to study the carbide type and distribution in the hardfaced deposit. It was observed that wear resistance increases with increasing Cr content in the alloy. Along with hardness, morphology and type of carbide are also important factors to decide the wear resistance. An attempt has been made to corelate the chemical composition, carbide morphology, and macrostructural features with wear properties of hardfacing alloys.