Browse Topic: Iron

Items (1,647)
Gray cast iron (GJL) is one of the oldest cast iron materials and is still in use in many applications in the automotive industry due to its good characteristics, in relation to lubrication, heat conductivity and damping. Engine parts particularly benefit from these parameters. Nevertheless, the design of these components has always been challenging, in terms of maximizing material utilization for lightweight designs for components under cyclic loading. In particular, with regard to the influence of the statistical (component size), geometrical (notches) and technological (microstructural) size effects, the existing guidelines and literature lack the necessary information to provide a comprehensive understanding of the cyclic material behavior of GJL materials. Within a comprehensive study, different GJL materials have been investigated at Fraunhofer LBF to provide more detailed information regarding the influence of size effects on fatigue strength. Accordingly, a variety of specimen
Bleicher, ChristophKansy, Axel
The improvement of heat dissipation performance of ventilated brake discs is vital to braking safety. Usually, the technical approaches shall be material optimization or structural improvement. In this paper, a simulation model of the heat transfer of brake discs is established using STAR-CCM+ software. Cast iron, aluminum metal matrix composite (Al-MMC), and carbon-ceramic composite materials (C-SiC) are compared. The results show that: Al-MMC has better thermal conductivity so that a more uniform temperature gradient distribution shall be formed; C-SiC has poorer heat capacity yet, according to previous studies, it has better thermal stability, which is the ability to ensure its friction factor under high-temperature condition; cast iron performs better with convective heat transfer rate, which enhances the heat transfer between the surface and surrounding flow field. Based on the results, this paper proposes four types of material combined brake discs using different friction
Wang, JiaruiJia, QingZhao, WentaoXia, ChaoYang, Zhigang
Gray cast iron is a cost-effective engineering material widely used for heavy duty engine blocks and brake rotor discs in vehicles. Thermomechanical fatigue (TMF) frequently occurs during vehicle operation due to temperature fluctuations in brake rotors. To speed up the design of the component, design structurally sounding brake rotors, and prevent premature thermally induced cracking, it is critical to investigate TMF behavior of the gray cast iron. This study presents a series of fatigue tests, including isothermal low cycle fatigue (LCF) tests at temperatures up to 700°C, as well as in-phase (IP) and out-of-phase (OP) TMF tests across various temperature ranges. Because of the asymmetric behavior in tension and compression, creep behaviors in both tension and compression and oxidation are also studied. These behaviors are the key to enable simulation of thermally induced cracks in rotors.
Liu, YiLee, HeewookHess, DevinCoryell, Jason
Wear-resistant, die-cast B390 aluminum represents a relevant material frequently used in the automotive industry. The wear and its relation to the microstructure along with different alloying additives is studied with efforts toward improved performance. Alloying by Sr allows for a lower Fe content helps in mitigating iron needling. This paper addresses wear performance of B390 and Sr-modified B390 alloys, tested against pearlitic cast iron, used for manufacture of piston rings. The wear tests were designed by using an ASTM G99 standardized pin-on-disc protocol at “wet” (motor oil) and “dry” conditions and were performed using a UMT (Bruker) benchtop tester. The polished cross-sections and friction surfaces were studied to identify the microstructural differences and dominating wear mechanisms. Interestingly, the stronger and harder Sr-modified B390 alloys wear more at dry conditions compared to the standard die-cast B390 alloy. This was ascribed to a change in wear mechanisms of the
Kancharla, Sai KrishnaJogineedi, RohitSingireddy, Vishal ReddyMirzababaei, SaerehDierks, MikeFilip, Peter
This research introduces a Detailed Digital Fuel Indicator (DDFI) system to enhance fuel monitoring accuracy in automobiles using advanced infrared (IR) sensor technology for precise fuel level detection. The innovative system includes a secondary tank, meticulously calibrated to the volumetric ratio of the primary tank, to ensure consistent and accurate readings. The DDFI system provides real-time data on fuel levels with an impressive accuracy of ±5%, a notable improvement over the traditional methods. Key components of the system include an IR sensor, a programmable integrated circuit (IC), and a secondary tank fabricated from galvanized iron (GI) sheet metal, ensuring durability and reliability in various environmental conditions. The system is designed to be user-friendly, offering an intuitive interface for drivers to monitor fuel levels effortlessly. Additionally, the DDFI system integrates seamlessly with existing vehicle systems, allowing for easy installation and minimal
Mallieswaran, K.Nithya, R.Rajendran, ShurutiArulaalan, M.
Most rechargeable batteries that power portable devices, such as toys, handheld vacuums, and e-bikes, use lithium-ion technology. But these batteries can have short lifetimes and may catch fire when damaged. To address stability and safety issues, researchers reporting in ACS Energy Letters have designed a lithium-sulfur (Li-S) battery that features an improved iron sulfide cathode. One prototype remains highly stable over 300 charge-discharge cycles, and another provides power even after being folded or cut.
A collaboration co-led by an Oregon State University chemistry researcher is hoping to spark a green battery revolution by showing that iron instead of cobalt and nickel can be used as a cathode material in lithium-ion batteries.
The essential aspect of an automobile is its braking system. Brakes absorb the kinetic energy of the rotating parts, i.e., wheels, and dissipate this energy into the surroundings in the form of heat. This entire process is quite complex, and the brake disc is subjected to extreme thermal and structural stresses along with deformation, which might damage the disc. This paper presents a structural and thermal analysis of an Audi Q3 brake disc using an ANSYS 2021-R1. The present brake disc is designed using SOLIDWORKS software. Composite materials are added in the ansys material library by adding their respective characteristics. The thermal analysis mainly focused on temperature variation and directional heat flux. The structural study was conducted to understand the stresses developed during braking and the deformations observed. Along with a comprehensive structural and thermal analysis, this work has also estimated the life of the brake disc, the factor of safety, and the real-time
Bahulekar, AtharvShiralkar, ShaunakJomde, AmitShamkuwar, SonalPatane, PrashantShinde, TarangDandin, Shahbaz
This article investigates the deformation mechanics of cast iron and its implications for notch analysis, particularly in the automotive industry. Cast iron’s extensive use stems from its cost-effectiveness, durability, and adaptability to various mechanical demands. Gray, nodular, and compacted graphite cast irons are the primary types, each offering unique advantages in different applications. The presence of graphite, microcracks, and internal porosity significantly influences cast iron’s stress–strain behavior. Gray and compacted cast iron display an asymmetrical curve, emphasizing low tensile strength and superior compression performance due to graphite flakes and crack closures. Nodular cast iron exhibits a symmetrical curve, indicating balanced mechanical properties under tension and compression. The proposed simplified macrostructural approach, based on monotonic stress–strain, aims to efficiently capture graphite and crack closure effects, enhancing compressive strength and
LaCourt, CameronLee, Yung-LiGu, Randy
The present work highlights the significance of nanocomposite coatings for their ease of processing and applicability in combating corrosion. Ongoing research is dedicated to the development of an effective nanocomposite hydrophobic coating. A hydrophobic nanocomposite coating was deposited on galvanized iron (GI) using a sol-gel route with polymethylsiloxane (PDMS) reinforced with nano-SiO2. Surface morphology and chemical composition analysis, conducted with scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDAX) and Fourier transform infrared spectroscopy (FTIR), revealed the coating’s structural and compositional attributes. The resulting hydrophobic coating exhibits a water contact angle (WCA) of 104.1°, indicating a 30.45% increase compared to bare GI. Subsequent to these characterizations, the adhesion of the coated GI, rated as 4B per ASTM D3359, is followed by commendable resistance to corrosion, as evidenced by electrochemical tests. The corrosion rate
Kumar, PrakashRamesh, M.R.Doddamani, Mrityunjay
A commonplace chemical used in water treatment facilities has been repurposed for large-scale energy storage in a new battery design by researchers at the Department of Energy’s Pacific Northwest National Laboratory. The design provides a pathway to a safe, economical, water-based, flow battery made with Earth-abundant materials. It provides another pathway in the quest to incorporate intermittent energy sources such as wind and solar energy into the nation’s electric grid.
Hey superhero fans, meet the researchers making real life Iron Man technology possible. In a new study, engineers from Korea and the United States have developed a wearable, stretchy patch that could help to bridge the divide between people and machines — and with benefits for the health of humans around the world.
Engine operation produces particles that contaminate the lubricating oil and can damage the engine's internal components. This paper presents a model for a three-coil inductive metal particle sensor and verifies the rationality and accuracy of the model by simulating the motion of a single spherical iron particle passing through the sensor. On this basis, the simulation of coupling double particles with different sizes, distances, and shapes is carried out. The study explores the influence of particle motion on the sensor-induced signal under various conditions. The research shows that when two particles pass through the sensor, the induced voltage signal will produce superposition when the distance between the two particles is small. The peak value of the induced voltage is 1-2 times the peak value of the induced voltage of a single particle. As the distance increases, the peak value of the induced voltage initially decreases, then slowly increases, and finally stabilizes. When the
Chen, SenShen, YitaoQiang, GuiyanZheng, ZhengWang, ZheyuHao, YinHu, Ting
Options for CNVII emission legislation are being widely investigated in a national program organized by China Vehicle Emission Control Center (VECC) since early 2020. It is foreseen that this possibly last legislation in China will have more stringent emission requirements compared to CNVI, including among other changes especially a further reduction of nitrogen oxide (NOx), inclusion of nitrous oxide (N2O) and sub-23 nm particle number (PN). This study investigates the technical feasibility to fulfill a CNVII emission legislation scenario, based on a modified CNVI 8 L engine operating under both cold and hot World Harmonized Transient Cycle (WHTC) and Low Load Cycle (LLC). Methods to address the challenges are discussed and validated, including application of a twin dosing system, electric heater, hybrid concepts of combining Copper (Cu-), Iron (Fe-) and Vanadium (V-) SCR technologies, filters with ultra-high filtration efficiency and optimization of engine calibration and urea dosing
Wang, YanChen, ShuyueZhang, JunChen, JunyinLong, LucasGeisselmann, AndreasBender, MichaelTao, ZeminZhu, Minlin
Just as NASA needs to reduce mass on a spacecraft so it can escape Earth’s gravity, automotive manufacturers work to reduce weight to improve vehicle performance. In the case of brake rotors, lighter is better for a vehicle’s acceleration, reliable stopping, and even gas mileage. Orbis Brakes Inc. licensed a NASA-patented technology to accomplish that and more. This revolutionary brake disc design is at least 42 percent lighter than conventional cast iron rotors, with performance comparable to much more expensive carbon-ceramic brakes.
This specification covers electrical iron in the form of bar, sheet, strip, and plate.
AMS E Carbon and Low Alloy Steels Committee
A University of Bristol-led study, published in The Proceedings of the National Academy of Sciences, demonstrates how to make conductive, biodegradable wires from designed proteins. These could be compatible with conventional electronic components made from copper or iron, as well as the biological machinery responsible for generating energy in all living organisms.
Austempered ductile iron (ADI) is an alternative to hardened steel for machined parts with high hardness, ductility, strength and fatigue strength. The optimal cutting parameters to perform turning operation on ADI with PCBN insert are predicted through the response surface methodology (RSM) approach. Design Expert Software was used to design fifteen experiment trials by changing cutting parameters including speed (N) rpm, feed (f) mm/min, and depth of cut (d) mm. The outcomes of the experiments were then examined. The mathematical model determined in the Analysis of Variance (ANOVA) satisfied output responses concerning the input parameters. The optimal turning parameters, N: 1039.11 rpm, f: .5 mm/min and d: 0.0974 mm is revealed the both responses. The confirmation experiment results revealed that the predicted value of responses is better in agreement with experimented responses. The optimal turning parameters recommended to industries application to machine the ADI with significant
Velusamy, K.Senthilkumar, K.M.Selvan, T.A.Viswanathan, A.
The ferrous deuteroporphyrin cast Fe alloy and nickel-coated steel were lap welded successfully using the mechanical stir welding process. It was able to weld junctions with full strength and fracture on the base metal side of nickel-coated steel during the welding process, but ferrous alloy and nickel steel could not be welded together. It was proposed that the joining technique and function of the Ni coating be used in the friction stir lap welding of Ni-coated steel and aluminum alloy. The Ni coating improved both the weldability of iron and steel, resulting in the production of a Fe-Ni eutectic structure with a low melting point at the interface of the two materials. It is possible to successfully fuse steel and ferrous metals together.
Sambath, S.Francis Xavier, J.Jayabalakrishnan, D.Suthan, R.Zahir Hussain, M.
One of the most promising applications for the use of hydrogen in vehicles is in the combustion engine. According to the legislation proposal being considered by European Union, hydrogen internal combustion engines (H2ICE) are zero emissions solution. Among the existing solutions, H2ICE is becoming the preferred one on long haul trucks and offroad applications. This is due to the high durability of the powertrain, the lower initial investment when compared to other alternatives, and the possibility of using low purity hydrogen. However, despite the high potential use of hydrogen, because of it is the smallest known chemical element, its use can result in the penetration of hydrogen into metallic materials, with the undesirable effect of embrittlement. This effect occurs mainly when the material surface is exposed to high temperatures and pressures, or under corrosion. By diffusing into the crystal lattice, hydrogen is accumulated in the interstices and crystalline defects, reducing the
Turola, JéssicaObara, Rafael BrisollaFerrarese, AndréAlbaneze, Aline Fernandade Souza Cabezas, Carlos
Low-carbon equivalent austempered ductile iron (LCE-ADI) exhibits high modulus of elasticity than conventional austempered ductile iron (ADI) due to less graphite content. Austempering parameters of temperature and time significantly influence the mechanical properties of LCE-ADI. In the present work, response of the material to two-step austempering in the range of 350–450°C was studied, and a comparison was made to single-step austempering. Reduction in ferrite cell size, increase in % carbon in carbon-stabilized austenite (CSA) and increase in volume fraction of CSA led to increase in tensile strength (10%) and hardness (20%), in addition to improved toughness (10%).
Maddi, LakshmiprasadDakre, VinayakLikhite, AjayPathak, Shailkumar
The work investigates the effect of different Iron and Manganese contents in ad-hoc cast specimens made from recycled EN AC-43200 alloy. Tensile tests and metallographic analyses coupled with energy dispersive X-ray spectroscopy measurements are carried out to elucidate the interplay between the microstructure and the quasi-static properties of the Aluminium-Silicon alloy under investigation. A strong correlation between the composition and morphology of Fe/Mn -based intermetallic precipitates and tensile properties is demonstrated. Moreover, it is found that specific intermetallic phases are present only for certain, relative and/or absolute contents of Fe and Mn.
Pavesi, AriannaCasari, DanieleMancini, AlessandroBonfanti, AndreaBarella, SilviaD'Errico, FabrizioBertasi, Federico
An EESM (Externally Excited Synchronous Motor) consists of a rotor with wound copper wires. One of its benefits is the ability to control the rotor electromagnetically with the rotor current, which is an advantage over an IPMSM (Internal Permanent Magnet Synchronous Motor). To practically use it and achieve optimal NVH quietness performance, the air- gap shape was redesigned to generate a sinusoidal curved magnetic flux density distribution. This differs from the standard design, in which the air gap has the same circumference as the rotor and stator. There was a significant reduction in the high-order magnetic flux density, which did not affect the torque. In addition, there was a reduction in the excitation force and minimal iron loss. Unlike an IPMSM, which only uses magnets and produces less heat, the copper wires of the EESM rotor generate heat as current flows through them. To maintain power density, it is important to ensure optimal cooling performance. A new cooling structure
Fan, XuWada, Hiroki
In most cases, the properties of a metal are evaluated in their as rolled condition, prior to any work hardening or bake hardening. But in the Automotive World, these steels get work hardened during the forming process and bake hardened in the paint shop. The goal of this paper is to evaluate the variations in the performance of Dual Phase (DP) steels and understand the most optimized method of testing and property generation. This method can then be used to extrapolate to real automotive components. Dual Phase Steels or DP Steels contain a mixture of Ferrite & Martensite from which they derive their name. They are a part of the advanced high strength and ultra-high strength steels steel family according to World Auto Steels. The Ferrite phase, with its iron content contributes to the material displaying an increased level of ductility whilst, the martensitic phase provides the steel with increased mechanical strength. These two properties together enable the steel to be highly
Vegi, NischayRagothaman, Balakrishnan
The automotive industry is facing a challenge as efficiency improvements are required to address the strict emission norms which in turn requires high performance downsized, lightweight IC engines. The increasing demand for lightweight engine needs high strength to weight ratio materials. To meet high strength to weight ratio, castings are preferable. However due to strength limitations for critical crankshaft applications, it forces to use costly forgings such as micro alloyed forging steel and Martensitic (after heat treatment) forging steel. To reduce the cost impact, high strength Austempered Ductile iron (ADI) casting is developed for crankshaft applications to substitute steel forgings. Austempered Ductile Iron is having an excellent mechanical properties due to aus-ferritic structure. The improved properties of developed ADI Crankshaft over steel forged crankshaft offers additional weight advantage. The ADI Crankshaft was subjected to rig test and meets the fatigue and
Yerra, UmamaheswaraGopal, ManishKolhe, Vivek MPalkar, VishalKumbhar, Dipak
Phosphating is the most preferred surface treatment process used for auto body sheet panel before painting due to its low-cost, easy production process, good corrosion resistance, and excellent adhesion with subsequent paint layer. There are different phosphating processes used for ferrous metal like zinc phosphating, iron phosphating, di-cationic & tri-cationic phosphating, etc. Among these phosphate coatings, the best corrosion resistance and surface adhesion are achieved by tri-cationic phosphate coatings (zinc-nickel-manganese phosphate). Many new technologies of phosphating are evolving. Key drivers for this evolution are increasing demand for higher corrosion resistance, multi-metal car body processing in same phosphating bath and sustainability initiatives to reduce the carbon footprints. We have evaluated two of these recent technologies. First technology being evaluated is low temperature phosphating in which phosphate bath temperature is reduced by 10°C and second is liquid
Balasubramanian, JayanthanKumar, VinayKirubakaran, MuthiahLalwani, Rahul
Diamond-Like Carbon (DLC) is a promising engine material for reducing friction and wear on sliding parts. By contrast, MoDTC lubricant additives are known to promote the wear of a-C:H films. However, the mechanism that promotes wear and the formation of tribofilms on DLC parts when in contact with molybdenum-based lubricant additives has not been sufficiently studied. The purpose of this research is to determine the wear promotion mechanism and formation of tribofilm on DLC by lubricant additives by comparing friction and wear properties. We conducted friction and wear tests using a tribometer with DLC (ta-C, ta-C:H, a-C, and a-C:H) blocks, FC250 (cast iron) rings, and oils containing lubricant additives (MoDTC, MoDTP, and Mo without DTC ligand) by observing and analyzing the sliding surfaces of specimens. No wear was observed for any of the DLCs (ta-C, ta-C:H, a-C:H, and a-C) in combination with oils containing MoDTP or Mo without DTC ligands. Oil containing MoDTC revealed low
Honda, TomomiKasai, MoritsuguMiyake, Koji
Light weight technologies are inevitable in the automotive industry to increase fuel efficiency and meet emission norms. An engine cylinder block is one of the major elements contributing approximately 3-4 % of the automobile weight. Aluminum cylinder block with cast-in liner is almost 40-55 % lighter than a conventional cast iron block [1] and hence the manufacturing processes and challenges associated with them are of high interest. A heterogeneous cast-in liner of gray cast iron in cast aluminum offers a low cost option, but the mechanical bond created between the liner and aluminum interface is prone to gap formation which affects the engine in terms of in-effective heat transfer, distortion and higher blow-by, and thereby high oil consumption & higher emissions. This study aims at reducing this interface bonding gap by in-depth study of critical process parameters involved in manufacturing of cylinder blocks. The study involved a single cylinder petrol engine block manufactured
D, BalachandarNataraj, Naveenkumar
Electric vehicle battery thermal management based on liquid cooling is the mainstream form of cooling for new energy vehicles. According to energy consumption, the system is divided into active cooling system and passive cooling system. The cooling of battery modules in these two cooling systems is carried out by liquid-cooled plate, which is connected in series in the cooling system. Therefore, the design of the liquid-cooled plate has a great impact on the effect of battery heat dissipation. In this paper, considering the advantages of existing liquid-cooled plates, the author proposed a series-parallel hybrid dc channel liquid-cooled plate structure, taking square lithium iron phosphate battery pack as the research object. Finally, the effects of different inlet flows and temperatures of the liquid-cooled plate on the thermal performance of the liquid-cooled plate were investigated by using single factor analysis. Studies have shown that the liquid-cooled structure can maintain the
Zhong, WenLi, MinShangguan, Wenbin
In comparison to aluminum, Compacted Graphite Iron (CGI) iron has superior mechanical properties, enables the use of parent bore running surfaces and fracture split main bearings, and provides advantageous NVH, package size, cost, and manufacturing CO2 profiles. Despite these advantages, aluminum blocks have leveraged density, and therefore weight, differentials to make considerable gains in the small, in-line passenger vehicle sector over the last 30 years. In order to demonstrate the potential benefits of CGI for small, in-line spark-ignition engines, the present study converted the cylinder block of a series production 1.2 litre three-cylinder engine from aluminum to CGI. Leveraging a novel design concept, with the running surface and load path constructed from high-strength CGI and the outer crankcase housing fabricated from durable, lightweight plastic, the assembled cylinder block achieved the same weight as the original aluminum block. NVH analyses showed that the global
Dawson, SteveFerrarese, AndreMarquard, Ralf
This specification covers a copper-zinc alloy (brass) in the form of wire.
AMS D Nonferrous Alloys Committee
Lithium-ion batteries (LIBs) have become a focus of research interest for electric vehicles (EVs) due to their high volumetric and gravimetric energy storage capability, lower self-discharge rate, and excellent rechargeability coupled with high operational voltage as compared with the lead-acid batteries. This paper presents different machine learning approaches to predict health indicators & usable cycle life of LIBs. Here, we focus on two important battery health indicators i.e., battery discharge capacity and Internal resistance (IR). We used publicly available multi-cycled data of the Lithium Iron Phosphate (LFP), Lithium-Nickel-Manganese-Cobalt-Oxide (NMC) and Lithium Cobalt Oxide (LCO) cells. The approach proposed for predicting health indicators involves using a time-series model in the areas where the actual data i.e., from the Beginning of life (BOL) to the End of life (EOL) is not available. This methodology includes dynamically training a time-series based regression models
Joshi, Umita DeepakGambhir, Ameya VMandhana, Abhishek
Reducing exhaust emissions has been a major focus of research for a number of years since internal combustion engines (ICE) contribute to a large number of harmful particles entering the environment. As a way of reducing emissions and helping to tackle climate change, many countries are announcing that they will ban the sale of new ICE vehicles soon. Electrical vehicles (EVs) represent a popular alternative vehicle propulsion system. However, although they produce zero exhaust emissions, there is still concern regarding non-exhaust emission, such as brake dust, which can potentially cause harm to human health and the environment. Despite EVs primarily using regenerative braking, they still require friction brakes as a backup as and when required. Moreover, most EVs continue to use the traditional grey cast iron (GCI) brake rotor, which is heavy and prone to corrosion, potentially exacerbating brake wear emissions. This study concentrates on emissions from a conventional grey cast iron
Ghouri, IshmaeelBarker, RichardBrooks, PeterKosarieh, ShahriarBarton, David
This specification defines limits of variation for determining acceptability of composition of cast and wrought corrosion and heat-resistant steels and alloys, maraging and other highly alloyed steels, and iron alloy parts and materials acquired from a producer.
AMS F Corrosion and Heat Resistant Alloys Committee
Calculating accurately iron bridge saturation effects of the magnetic field, for Permanent Magnet Assisted Synchronous Reluctance Motors (PMASynRMs), remains to be a knotty problem. This paper presents an analytical modeling method to predict open-circuit magnetic field distributions and electromagnetic performances of PMASynRMs, considering iron bridge saturation effects. This analytical modeling method combines the magnetic equivalent circuit method, superposition principle, the solution of the governing Maxwell’s field equations and a complex relative permeance function. A quadruple-layer PMASynRM are remodeled into four surface-inserted permanent magnet synchronous motors (SPMSMs) which have different surface-inserted permanent magnets. Each layer of the interior permanent magnets of the PMASynRM is transformed into a new equivalent surface-inserted permanent magnet whose equivalent thickness needs to be defined by the magnetic equivalent circuit method due to iron bridge
Liu, ChangZuo, ShuguangHu, XiaoruiChen, SiyueWu, Zhipeng
Sehitoglu damage model is often applied to evaluate thermomechanical fatigue (TMF) performance of the components in the environment of high temperature in finite element analysis (FEA). SiMo ductile cast irons have been widely used for exhaust manifolds in propulsion systems. The manifold experiences TMF due to the limitation of thermal expansion in the assembled condition. Mechanical strain and damage are therefore introduced by the constraints. On the other hand, it is known that ductile cast iron exhibits embrittlement at the temperature around 400°C due to the addition of magnesium (Mg) in order to obtain graphite nodules. This mechanical behavior at 400°C, which has to be considered in design, makes the ductile cast irons only partially satisfy the assumptions of the Sehitoglu damage model. In the present work, a two-step approach is presented to evaluate the sensitivity of the manifold geometry to the 400°C embrittlement using the Sehitoglu model. A strain-life (E-N) curve of the
Liu, YiKunduru, PurushothamSivagnanam, ThirumalaignanaCai, NaChen, JimZhang, WenshengLamonaca, Gianni
Electric machines in aerospace applications are subjected to extremely high operating temperatures. This increases coercivity or decreases saturation flux density of the electrical steel resulting in increased core loss. The need for high power density and increased operating speed favours the use of thin gauge Silicon Steel (Si-Fe) and Cobalt Iron (Co-Fe) laminations for aerospace applications. Therefore, the variation in iron loss is studied for three grades of Si-Fe laminations by subjecting them to controlled ageing in laboratory. The analysis is also provided over a range of flux density and frequency to generalize the phenomenon over the operating domain. The results of ageing the laminations are in turn used to predict the degradation in performance of a 1.15 MW, 16-pole 48-slot propulsion machine for aerospace application. The degradation is estimated in terms of variation in iron loss. Iron loss is found to vary over a wide range (-11% to 5%) for thick gauge 0.35 mm SiFe
Ramanathan Mathavan Jeyabalan, Ram KumarVakil, GaurangGerada, DavidGerada, ChrisMinshull, James
Electric machines offering a high power density are required for aerospace applications. Soft magnetic material with a high saturation flux density is one of the key component which is required to realize these power density targets. The need for a high saturation flux density necessitates the use of cobalt iron lamination over the conventional silicon steel. However, cobalt iron is very expensive i.e. order of 10 in comparison to silicon steel. Stator segmentation is identified as an appropriate method to reduce the wastage and cost associated with lamination. Consequently, in this paper, stator segmentation is analyzed on a 1.35 MW, 16-pole 48-slot propulsion machine. The impact of manufacturing is accounted by controlling the resulting airgap between the segmented structures. Electromagnetic performance for various segmented topologies are compared in terms of torque, torque ripple, and iron loss. Average torque is found to degrade by nearly 10% with an increase in the number of
Ramanathan Mathavan Jeyabalan, Ram KumarVakil, GaurangGerada, DavidGerada, ChrisMinshull, James
This study aims to present a numerical structural validation procedure for the drum brake spider component. To implement the procedure, the ANSA, ABAQUS, Fe-Safe, and Minitab engineering software were used for stress analysis, fatigue life calculation, and statistical validation using Weibull distribution. The results obtained from these tools allowed us to determine with acceptable error the spot failure of the component and the number of cycles until the occurrence of the failure. The input data to support the pre-processing of the numerical model and obtain the virtual results were determined from the application and analysis of the following methods: determination of the stress strain curve of the Spheroidal Graphite Iron (SG) material of the component, applied to Theory of Critical Distance (TCD) of fracture mechanics and evaluation of the behavior of Nodular Cast Iron under fatigue life. Given the non-linear characteristics under the conditions of use, the need for correction of
Marcon, LucasAnselmo, Pablo TonettiNascimento, VagnerVieceli, AlexandreCorso, Leandro
The reliable chemical characterization of non-exhaust emissions generated by brakes is of fundamental importance in order to provide correct information for source apportionment studies as well as for their toxicological and environmental assessment. Nowadays, the best option to obtain samples of PM10 emissions composed only by material worn from the tribological interface, i.e. the braking disc (BD) and the friction material (FM) rubbing surfaces, is to sample them on suitable collection filters at a dedicated dyno-bench, during a standard braking test cycle. In particular, the use of enclosed dyno-bench is necessary for excluding other spurious contributions from the environment, while defined test cycles are necessary to simulate standard driving conditions. Nevertheless, different braking cycles are usually characterized by different overall temperature profiles or energy parameters, which in the end have significant influence on the wear and the oxidation of the materials involved
Mancini, AlessandroTsyupa, BozhenaPin, SoniaBandiera, MarcoBertasi, FedericoFederici, MatteoBonfanti, AndreaPerricone, GuidoGigli, LaraBolzacchini, Ezio
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