Effect of change in temperature on the tribological performance of micro surface textured DLC coating

In this study, surface texturing and hydrogenated amorphous carbon (a-C:H) diamond-like carbon (DLC) coating was combined to evaluate the coating performance at various temperatures in oil lubricated reciprocating sliding tests. Micro dimples were created by laser surface texturing on M2 steel using a Pico second laser. DLC coating was deposited by hybrid magnetron sputtering on textured substrates. Textured a-C:H showed stable coefficient of friction at 30, 80, and 125 °C compared to un-textured a-C:H. At 30 °C, graphitization was not observed for both textured and un-textured DLC coating. Graphitization was more pronounced in the case of un-textured a-C:H at 80 and 125 °C. Results show that, at all temperatures tested (30-125 °C), DLC textured samples showed higher wear resistance compared to un-textured DLC coating. The improvement in wear resistance can be explained by the lower graphitization of textured DLC coating. Lower graphitization in the case of textured DLC might be due to the wear particle capturing and lubricant retention ability of textures

Influence of poly(methyl acrylate) additive on cold flow properties of coconut biodiesel blends and exhaust gas emissions

Biodiesel comprises fatty acid esters and is used as an alternative fuel for diesel engines. However, biodiesel has poor cold flow properties (i.e., CP, CFPP and PP) than mineral diesel fuel. This study aims to reduce the PP, CFPP and CP of coconut biodiesel (CB) blends using poly(methyl acrylate) (PMA) additives and investigate their effects on single-cylinder four-stroke diesel engine performance and exhaust gas emission. DSC and TGA were used to observe crystal behavior and thermal stability of the biodiesel fuel blends. Engine performance and emission were analyzed by Dynomax-2000 software and gas analyzer, respectively. Results showed that 20% of CB blended with diesel and 0.03 wt% of PMA showed significant improvement in the PP, CFPP and CP. Other properties of B20 with additives met the requirements of ASTM D6751. The BSFC of B20 with PMA was reduced by 3.247%, whereas the BTE was increased by 2.16%, compared with those of B20. Burning B20 with PMA increased the NO emission by 2.15%, whereas HC, CO and smoke emissions were 19.81%, 13.35% and 3.93% lower than those of B20, respectively. Therefore, CB20 blend with 0.03 wt% PMA can be used as an alternative fuel in cold regions without compromising fuel quality

Assessment of friction and wear characteristics of Calophyllum inophyllum and palm biodiesel

When an automobile engine is running it produces more friction and wear between the sliding components and lubrication is required for reducing the frictional effect. Friction and wear reduce engine life, reliability and increase the maintenance cost. This study investigated and compared the friction and wear characteristics of diesel, Calophyllum inophyllum, palm biodiesel, and their blends, by using the four-ball tester. The experimental test was conducted at 30°C, 45°C, 60°C and 75°C, under 40kg and 80kg loads, at a constant speed of 1800rpm for all samples. The average coefficient of friction of diesel was 28.8% and 23.4% higher than pure C. inophyllum and palm biodiesel respectively. The wear scar diameter of diesel was higher than biodiesel and biodiesel blends at different temperatures and loads. The highest amount of elements were found from CIB100 (45ppm), which changes by about 14.6ppm compared to ordinary oil. PB10 and PB20 have lower amounts of metal composition and oxide formation. PB20 exhibits a lower worn scar surface area than diesel and biodiesel blends. PB20 shows good lubrication performance and the possibility to form highly lubricating film without breaking down over a long time

Assessment of performance, emission and combustion characteristics of palm, jatropha and Calophyllum inophyllum biodiesel blends

Biodiesel is an alternative diesel fuel that is produced from renewable resources. Energy studies conducted over the last two decades focused on solutions to problems of rising fossil fuel price, increasing dependency on foreign energy sources, and environmental concerns. Palm oil biodiesel is mostly used in Malaysia. Engine performance and emission tests were conducted with a single-cylinder diesel engine fueled with palm, jatropha and Calophyllum inophyllum biodiesel blends (PB10, PB20, JB10, JB20, CIB10, and CIB20) and then compared with diesel fuel at a full-load engine speed range of 1000–2400 rpm. The average brake specific fuel consumption increased from 7.96% to 10.15% while operating on 10%, and 20%, blends of palm, jatropha and C. inophyllum biodiesel. The average brake power for PB10 and PB20 were 9.31% and 12.93% lower respectively compared with that for diesel fuel. JB10 showed higher amount of brake specific fuel consumption than diesel and other biodiesel blends. PB20 produces comparatively lower CO and HC emissions than diesel and biodiesel blends. JB10 showed 31.09% lower smoke opacity than diesel fuel. Diesel produces lower amount of NOX emission compared to biodiesel blends. The higher peak cylinder pressure and heat release rate were found with CIB blends compared to diesel fuel, palm and jatropha biodiesel blends. Results indicated that PB20 has better engine performance, and lower emission compared with diesel and biodiesel blends. Thus, PB20 is suitable for use in diesel engines without the need for any engine modification

Influences of thermal stability, and lubrication performance of biodegradable oil as an engine oil for improving the efficiency of heavy duty diesel engine

Nowadays, the development of biodegradable products is important in improving energy efficiency and green environment, particularly in energy conservation and rotation of machinery systems. In the case of sliding components, lubrication system and lubricant quality plays an important role for energy efficiency as it is directly involved with frictional force and components wear characteristics. The conventional mineral oil-based lubricant is used for machinery lubrications; however, it is nonbiodegradable and is an environmental pollutant. This investigation attempts to develop biolubricant acquired from various vegetable oils to replace mineral oil-based lubricants. This study evaluates the physicochemical properties, thermal stability, and lubricating and tribological characteristics of olive oil and its comparative analysis with commercial lube oil. A four-ball tribotester was used to measure the friction and wear properties of the sample according to the ASTM 4172 method. Olive oil has an excellent oxidation stability due to the presence of high percentages of oleic acid in fatty acid composition. Olive oil showed higher viscosity index and kinematic viscosity than other vegetable oils; hence, it is better for boundary lubrication. Thermogravimetric analysis showed that olive oil persists thermally steady up to 390 °C. Olive oil showed a lower coefficient of friction, wear scar diameter, and worn scar surface area than commercial lube oil. Therefore, due to the better lubricating performance, olive oil has high potential for use as an engine lubricating oil for improving efficiency of heavy-duty engines in the automotive applications

Impact of edible and non-edible biodiesel fuel properties and engine operation condition on the performance and emission characteristics of unmodified DI diesel engine

The purpose of this work is to test the feasibility of biodiesel as a substitute for diesel used in a direct injection (DI) diesel engine. The biodiesel was produced by an esterification and transesterification process. Experiments were conducted with diesel–biodiesel blends containing 10 and 20% biodiesel with the diesel fuel. The results of the biodiesel blends are compared with baseline diesel which was assessed at constant speed in a single cylinder diesel engine at various loading conditions. The physicochemical properties of palm and Calophyllum inophyllum biodiesel and their blends meet the standard specification ASTM D6751 and EN 14214 standards. The maximum brake thermal efficiency was attained with diesel fuel, 10% palm biodiesel (PB10) and 10% C. inophyllum biodiesel (CI10) at all load condition except low load condition. Engine emission results showed that the 20% C. inophyllum with 80% diesel blend exhibited 6.35% lower amount of brake specific carbon monoxide, and the PB20 blend and CI20 blend reduced brake specific hydrocarbon emission by 7.93 and 9.5%, respectively. NOx emission from palm and C.inophyllum biodiesel blends are found to be 0.29–4.84% higher than diesel fuel. The lowest smoke intensity is found at 27.5% for PB10 and CI10 biodiesel blends compared with diesel fuel

Surface Texture Manufacturing Techniques and Tribological Effect of Surface Texturing on Cutting Tool Performance: A Review

The tribological characteristics of sliding surfaces have been remarkably improved by surface texturing. Surface texturing can be beneficial in many ways; for example, it can reduce friction and wear, increase load carrying capacity, and increase fluid film stiffness. The design process for surface texturing is highly correlated to the particular functions of any application for which texturing is required. Texture quality is greatly affected by manufacturing methods, therefore, it is important to have a detailed understanding of the related parameters of any technique. The use of surface texturing to improve the cutting performance of tools is a relatively new application. These textures improve cutting performance by enhancing lubricant availability at the contact point, reducing the tool-chip contact area, and trapping wear debris. Reductions in crater and flank wear, friction force, cutting forces, and cutting temperature are the main benefits obtained by this technique. To date, surface texturing has been successfully used in drilling, milling, and turning operations. This article provides an overview of the techniques that have been used in industry and research platforms to manufacture micro-/nano-textures for tribological applications, and it examines the effects of surface textures on cutting tool performance

Analysis of thermal stability and lubrication characteristics of: Millettia pinnata oil

Lubricants are mostly used to reduce the friction and wear between sliding and metal contact surfaces, allowing them to move smoothly over each other. Nowadays, due to the increase in oil prices and reduction of oil reserves, it is necessary to replace mineral oil, which will also protect the environment from hazards caused by these oils. It is essential to find an alternative oil for the replacement of mineral-oil-based lubricants, and vegetable oil already meets the necessary requirements. Vegetable-oil-based biolubricants are non-toxic, biodegradable, renewable and have a good lubricating performance compared to mineral-oil-based lubricants. This study analyzes the thermal stability and lubricating characteristics of different types of vegetable oil. The friction and wear characteristics of the oils were investigated using a four-ball tester, according to ASTM method 4172. Millettia pinnata oil has good oxidation stability due to the presence of higher percentages of oleic acid in its fatty acid composition. Millettia pinnata oil also shows a higher kinematic viscosity. Rice bran oil shows a higher viscosity index than other oils, and it is better for boundary lubrication. In thermogravimetric analysis, it was found that Millettia pinnata oil remains thermally stable at 391 °C. Millettia pinnata oil showed a lower coefficient of friction and rice bran oil showed a lower wear scar diameter compared to other vegetable oils and lube oils. A lower wear scar surface area was found with rice bran oil compared to other vegetable and commercial oils. Therefore, due to a better lubricating performance, Millettia pinnata oil has great potential to be used as a lubricating oil in industrial and automotive applications

Optimization of performance, emission, friction and wear characteristics of palm and Calophyllum inophyllum biodiesel blends

A running automobile engine produces more friction and wear between its sliding components than an idle one, and thus requires lubrication to reduce this frictional effect. Biodiesel is an alternative diesel fuel that is produced from renewable resources. Energy studies conducted over the last two decades focused on solutions to problems of rising fossil fuel price, increasing dependency on foreign energy sources, and worsening environmental concerns. Palm oil biodiesel is mostly used in Malaysia. This study conducted engine performance and emission tests with a single-cylinder diesel engine fueled with palm and Calophyllum inophyllum biodiesel blends (PB10, PB20, PB30, CIB10, CIB20, and CIB30) at a full-load engine speed range of 1000-2400 rpm, and then compared the results with those of diesel fuel. Friction and wear tests were conducted using the four-ball tester with different temperatures at 40 and 80 kg load conditions and a constant speed of 1800 rpm. The average brake specific fuel consumption increased from 7.96% to 10.15% while operating on 10%, 20%, and 30% blends of palm and C. inophyllum biodiesel. The respective average brake powers for PB20 and PB30 were 9.31% and 12.93% lower compared with that for diesel fuel. PB20 produced relatively lower CO and HC emissions than the diesel and biodiesel blends. Diesel produced low amounts of NOX emission, and the CIB blend produced a lower frictional coefficient compared with the diesel and PB blends. PB30 showed high average FTP and low average WSD, both of which enhanced lubricating performance. An average metal element composition was found in PB20 under the 40 and 80 kg load conditions. PB20 showed lower worn scar surface areas compared with the diesel and biodiesel blends. Results indicated that PB20 has better engine performance, lower emission, and good lubrication properties compared with diesel and biodiesel blends. Thus, PB20 is suitable for use in diesel engines without the need for any engine modification