Search Results

Additive manufacturing is currently being investigated for the production of components aiming for near net shape. The presence of chopped glass fibers with PA6 increases the melt viscosity and also changes the coefficients of thermal expansion and increase the heat resistance. The great dimensional stability obtained with the fusion of the PA6 with the fiber results in an extremely durable material even in adverse environments for many other materials used in 3D printing. PA6 is a material oriented for users who need to make structural parts and exposed to high mechanical stresses. The impact, test tensile, and flexural results for as-built PA6 with various infill patterns, including grid, triangle, trihexagon, and cubic, are tested.

This study delves into the innovative realm of synthesizing surface alloyed materials by utilizing copper-based metamorphic powders subjected to high-intensity electron beam irradiation. The process involves depositing metamorphic particles onto a stainless-steel substrate, and subsequently exposing the assembly to a powerful electron beam, resulting in the development of distinct surface alloyed layers. A notable advancement was achieved by introducing a second layer of metamorphic powders over the existing alloyed layer, followed by further treatment with the electron beam. The alloyed layers, characterized by a volumetric concentration ranging from 60 to 67%, exhibited a fascinating phenomenon— the formation of abundant borate crystals with the chemical formula Al2.56Fe1.75Ni0.84. This crystal presence significantly elevated the hardness of the surface alloyed layers, showcasing an impressive five to sevenfold increase compared to the substrates.

Bimetal composite pipe has higher strength and is more corrosion and high temperature resistant compared to single metal pipe, making it a new type of pipe that is being gradually applied to important industrial fields such as aviation and aerospace manufacturing. To study the hydraulic forming mechanism of bimetal composite pipes, the forming process is divided into three stages: liner pipe elastic–plastic deformation, base pipe loading, and unloading. The stress and strain relation between the liner and base pipe during the gradual increase in hydraulic pressure is analyzed, and the range of selected internal pressure required for composite pipe formation and the relation between residual contact pressure and internal pressure for the liner–base pipe interface are obtained.

For a quick reach to the operating temperatures, the three way catalytic converter is recently located closer to the engine and subjected to higher temperatures than before. At the same time, the three way catalytic converter has upper thermal limits. Therefore, the operating temperatures have to be estimated accurately in the early period of product development. In this research, the four analysis methods are linked with the one-dimensional engine cycle simulation to achieve the goals. Firstly, for the estimation of gas temperatures at the exhaust port of the engine, the combustion analysis using the 3D-CFD was conducted to accurately simulate the way the heat was generated. Then, for the estimation of heat dissipation from the exhaust system to the atmosphere, the heat conduction analysis coupled with the air flow analysis around the vehicle body using the 3D-CFD was conducted.

Magnet wire is composed of a conducting core and thin layer of electrical insulation. Copper (Cu) is typically used as conducting core, and various polymers such as polyamideimide, polyimide, and polyesterimide are used for electrical insulation. The role of the magnet wire is related to the interchange between electrical and mechanical energy for energy transformation application such as transformers, motors, generators etc. Currently, the electric vehicles (EV) industry is growing rapidly and demands on related components are therefore increasing. Compared to the combustion engine, EV needs more electrical power with higher voltages or higher currents, which can increase probability of electrical discharge. The degradation of the insulation layer can occur by polymer bond breakage due to electrical stresses under partial discharge. To keep high performance under higher voltage, insulating polymers should have high heat and chemical resistance as well as low water absorption.

A common way to reduce the noise of automotive powertrains, both with internal combustion engine (ICE) and electric driveline, is to cover their noise radiating areas. However, the parts used for this purpose, besides being effective from the NVH standpoint, also have to fulfil several non-NVH requirements. For ICE, they have to provide a certain level of thermal insulation while favoring the reduction of fuel consumption and CO2 emissions. For electric powertrains, lightweight, environmental footprint and sustainability become preponderant in the design of engine covers. Combining these multidimensional requirements, a new fiber-based mono-material product for engine-mounted applications is proposed. It is able to provide optimum noise protection in the passenger cabin and greater driving comfort while keeping high level of sustainability, good heat resistance and relatively low weight.

To improve the thermal efficiency of next-generation engines, the cylinder pressure will be increased further, and thermal load is expected to increase. In addition, to reduce friction loss, the use of low viscosity oils is also being considered. These changes will make the sliding condition of piston rings much more severe, especially for Heavy Duty Diesel (HDD) engines. Therefore, piston rings require surface treatment on their peripheral surface, not only to prevent wear and scuffing, but also to reduce the friction force. Consequently, Diamond-like Carbon (DLC) coatings have been adopted recently as surface treatment for piston rings. However, heat resistance of DLC coatings is known to be low, and suggestions have been made that these coatings are not suitable for use under high temperature environment.

Off highways vehicles especially tractors are prone to operate on fields where tractors are exposed to dry crops, chaffs (the husks of corn or other seed separated by winnowing or threshing) and particles which can catch fire easily when it is exposed to surface/skin temperature of more than 200 degree Celsius. It will be a basic projection that tractor will be having vertical exhaust tube at a height but there are certain tractors and applications where exhaust pipe must be below certain height, and which will be close to the ground. In these scenarios the skin temperature of exposed exhaust tail pipe part must be within a limit and that must be within the existing design. Break firing point of chaffs and husk also experimented at different moisture level. Several options are being verified on different heat flow and geometry changes, additional air entry jet nozzle with double pipe arrangement.

One of the prominent representatives of heat-resistant polymers was the class of Polyethylene Terephthalate Glycol (PETG) with high-strength, but still lightweight. The carbon fiber with PETG (CFPETG) composites also gives even more resistance to heat and chemical, creating it a demandable choice of application in automotive and other industrial components. This paper aims to study the most significant process parameter of FDM technique for different infill density of 25%, 50%, 75%, and 100% at various sliding load condition and sliding distance on wear and friction characteristics of PETG and CFPETG under annealed condition was investigated via dry sliding tribometer apparatus. The trials were done by applying the load of 10N, 20N, 30N, 40N, with a sliding distance of 1000m, 2000m for the time period of 10 min at room temperature and responses such as wear rate and coefficient of friction were recorded for further analysis.

The permanently tightening emission regulations for nitrogen oxides (NOx) pollutants force further development of mobile exhaust aftertreatment systems with selective catalytic reduction (SCR). Of particular interest is the long-term reliability of SCR-systems with regard to unfavorable operating conditions, such as high injection rates of urea water solution (UWS) or low exhaust gas temperatures. Both may lead to the formation of solid deposits which decrease system efficiency by increasing backpressure and impairing ammonia formation. In order to study the most relevant processes of deposit formation, an optical box with heat resistant glass was designed. Three UWS injectors with different spray characteristics were used to study their influence on the deposit formation under a wide range of stationary and transient operating conditions. Infrared thermography was applied to observe spray-induced wall cooling, both below and above the Leidenfrost point.

Current intercooler hoses, which are made from fluorocarbon rubber (FKM) and silicone rubber (VMQ) exhibit high heat resistance and durability. However, they will be used in more severe use environments, and there is a risk of problems arising with their current material composition. This investigation into issues concerning intercooler hoses in future engines found that FKM mechanical properties were insufficient under high temperature environments. In this research, efforts to improve the mechanical properties of FKM focused on the low durability of the internal FKM crosslinking points as the cause of this insufficiency. The current crosslinking method has excellent acid resistance and cannot be modified. An effective improvement the properties was therefore sought by adding a new distinct crosslinking network while preserving the current level of acid resistance of the existing network. Carbon black gel was used as a reinforcing agent to form the new network.

The cooling performance and the heat resistance performance of commercial vehicle are balanced with aerodynamic performance, output power of powertrain, styling, cost and many other parameters. Therefore, it is desired to predict the cooling performance and the heat resistance performance with high accuracy at the early stage of development. Among the three basic forms of heat transfer (conduction, convection and radiation), solving thermal conduction accurately is difficult, because modeling of “correct shape” and setting of coefficient of thermal conductivity for each material need many of time and efforts at the early stage of development. Correct shape means that each part should be attached correctly to generate the solid mesh with high quality. Therefore, it is more efficient and realistic method to predict the air temperature distribution around the rubber/resin part instead of using the surface temperature at the preliminary design stage.

Further improvements in catalyst performance are required to help protect the atmospheric environment. However, from the viewpoint of resource availability, it is also necessary to decrease the amount of precious metals used at the active sites of the catalyst. Therefore, a high-performance three-way catalyst with an advanced coating layer has been developed to lower the amount of precious metal usage. Fuel efficiency improvement technologies such as high compression ratios and a large-volume exhaust gas recirculation (EGR) generally tend to increase the ratio of hydrocarbons (HC) to nitrogen oxides (NOx) in exhaust gas. This research focused on the palladium (Pd) loading depth in the coating layer with the aim of improving the hydrocarbon (HC) conversion activity of the catalyst.

In order to improve the accuracy of the coil temperature prediction, detailed fundamental experiments have been conducted on thermal resistances that are caused by the void air gap and contact surfaces. The thermal resistance of the coil around the air gap can be calculated by an air gap distance and air heat conductivity. Contact surface thermal resistance between the core and the housing was constant regardless of the press-fitting state in this experiment. Prediction accuracy of the coil temperature is improved by including the heat resistance characteristics that is obtained by the basic experiment to conjugate heat transfer analysis model.

In the current scenario, durable exhaust system design, development and manufacturing are mandatory for the vehicle to be competitive and challenging in the automotive market. Material selection for the exhaust system plays a major role due to the increased warranty requirements and regulatory compliances. The materials used in the automotive exhaust application are cast iron, stainless steel, mild steel. The materials of the exhaust systems should be heat resistant, wear and corrosion resistant. Stainless steel is the most commonly used material in the automotive exhaust system. Due to increasing cost of nickel and some other alloying elements, there is a need to replace the stainless steel with EN 8 steel. Recent trends are towards light weight concepts, cost reduction and better performance. In order to reduce the cost and to achieve better wear and corrosion resistance, the surface of the EN 8 steel is modified with coatings.

One of the reasons for the large number of road accidents on highways in Ukraine [1] is the instability of the braking properties due to the unstable characteristics of the brake mechanisms’ friction pairs. The manufacturer produces new automobiles with installed brake pairs (brake pads and their counter bodies), which have passed long-term tests for the stability of the friction coefficient and braking forces distribution of between the axles. This ensures the compatibility of the friction pairs characteristics for front and rear brake mechanisms according to the criteria of heat resistance. During operation, instead of worn-out brake pads, brake discs and drums, drivers can purchase new ones, manufactured as spare parts. However, in the well-known literature there are no methods that allow to check the compatibility of the friction pairs characteristics for front and rear brake mechanisms according to the criteria of heat resistance.

This paper describes a newly developed motor and inverter system with maximum torque of 320 Nm and maximum power of 110 kW for a 2018 model year EV. The system achieves this performance with no increase in size from the previous 2013 model year system with maximum torque of 254 Nm and maximum power of 80 kW. The specific features of the new system described in this paper are summarized below. A new inverter power module that adopts a direct cooling structure produces higher current density than the previous model. The designs of components experiencing structural and electrical variation that affects heat generation by the power semiconductors were confirmed. Furthermore, the motor temperature is estimated for thermal protection. These features allow for control logic that can optimally manage the temperatures of the power semiconductors and the motor to facilitate the high torque performance of the system.

Growing concerns about the depletion of raw materials as vehicle ownership continues to increase is prompting automakers to look for ways of decreasing the use of platinum-group metals (PGMs) in the exhaust systems. This research has developed a new catalyst with strong robustness against fluctuations in the exhaust gas and excellent nitrogen oxide (NOx) conversion performance. One of the key technologies is a new OSC material that has low surface area (SA) and high OSC performance. We enhanced the pyrochlore- ceria/zirconia (CZ) which has a very small SA. In order to enhance the heat resistance and promote the OSC reaction, we selected and optimized the additive element. This material showed high OSC performance especially in the temperature range of 400 degrees or less. Another key technology is washcoat structure that has high gas diffusivity by making connected pore in the washcoat (New pore forming technology).

A Vapor Envelope is an ultra-thin-walled vapor chamber that enables a unique combination of lighter weight, lower profile, and lower cost for heat spreading or heat removal applications. It evolved from work done as part of a DARPA program on Thermal Ground Planes. This paper examines a published testing protocol for the measurement of the thermal resistance of thin flexible thermal ground planes. It then applies an adapted version of the published technique to measure the thermal resistance of a vapor envelope and a dimensionally equivalent solid copper heat spreader. Finally, it looks at the implications of a significantly lower thermal resistance for a specific configuration. The analysis of whether this adapted technique would provide a sufficient metric for industrial application identified the control and understanding of the thermal interface materials as a key determinate.

Oven and flame tests were designed and conducted to evaluate the heat resistance of a ceramic coating material, Cerakote C-7700Q, and evaluate its viability to replace the intumescent coating as one painting material for helicopter engine cowlings. The test results showed that the currently used painting scheme of the engine cowlings failed the 220°C oven test while after replacing the epoxy seal coat with the Cerakote, the new painting system passed the 220°C test in regards to painting bubbling. This study explained why serious appearance defects occurred in the inner skin of the engine cowling when the aircraft is hovering and suggested that one most time- and cost-effective solution is to repaint the current engine cowlings with a new three coating system of Cerakote, surface protection HS7072-622, and intumescent paint as a fireproof lacquer.