Search Results

Abstract The current investigation studies the microstructure and high-temperature hot corrosion behavior of plasma-sprayed coatings. The composition of Fe17Cr2Ni0.18C and fly ash cenosphere powder is maintained in the 0%, 5%, 10%, and 15% ratio by weight percent, respectively. Both powder mixtures were thoroughly blended correspondingly and coated on T22 boiler steel tubings. Thermocyclic hot corrosion studies were examined in a liquid salt condition of Na2SO4—60% V2O5 for 17 cycles of 51 h at 600°C on bare and coated steels. Thermogravimetric practice was used to establish the kinetics of hot corrosion of uncoated and coated steels. As-coated samples are studied for microstructure and microhardness. X-ray diffraction (XRD), scanning electron microscopy (SEM)/energy-dispersive spectroscopy, and X-ray mapping characterization techniques have been utilized for structural analysis of the as-coated and hot-corroded samples.

Abstract Automotive-grade high-strength steels are galvanized for improved corrosion resistance. However, selective oxidation of alloying elements during annealing heat-treatment may influence the subsequent zinc (Zn) coating quality. The formation of internal and external oxides depends on the alloy composition, especially the Si/Mn ratio, and the oxygen potential of the annealing atmosphere. In this work, a dual-phase (DP) steel was intercritically annealed with varied fuel-to-air ratios in a direct-fired furnace and then galvanized in a Zn bath with 0.2 wt% Al. The type of internal and external oxides and the interfacial structures between the steel substrate, the Al-Fe-Zn inhibition layer, and the Zn coating were examined by using site-specific focused ion beam (FIB) and transmission electron microscopy (TEM).

Abstract A key element in an ergonomically designed driver’s seat in a car is the correct identification of driver seating position and posture accommodation. Current practice by the automotive Original Equipment Manufacturer (OEM) is to utilize the Society of Automotive Engineering (SAE) J1517 standard practice as a reference. However, it was found that utilizing such guidelines, which were developed based on the American population, did not fit well with the anthropometry and stature of the Malaysian population. This research seeks to address this issue by comparing the SAE J1517 Model against Malaysian preferred driving position. A total of 62 respondents were involved for the driver seating position and accommodation study in the vehicle driver’s seat buck mockup survey and measurements. The results have shown that the Malaysian drivers prefer to sit forward as compared to the SAE J1517 Model and have shorter posture joint angle.

Abstract Autonomous vehicles (AVs) are being rapidly introduced into our lives. However, public misunderstanding and mistrust have become prominent issues hindering the acceptance of these driverless technologies. The primary objective of this study is to evaluate the effectiveness of a driving simulator to help the public gain an understanding of AVs and build trust in them. To achieve this aim, we built an integrated simulation platform, designed various driving scenarios, and recruited 28 participants for the experiment. The study results indicate that a driving simulator effectively decreases the participants’ perceived risk of AVs and increases perceived usefulness. The proposed methodologies and findings of this study can be further explored by auto manufacturers and policymakers to provide user-friendly AV design.

Abstract Combining ball milling with stir casting in the synthesis of nanocomposites is found effective in increasing the strength and ductility of the nanocomposites. In the first step, the nanoparticles used as reinforcement are generated by milling a mixture of aluminum (Al) and manganese dioxide (MnO2) powders. A mixture of Al and MnO2 powders are mixed in the ratio of 1:2.4 by weight and milled at 300 rpm in a high-energy planetary ball mill for different durations of 120 min, 240 min, and 360 min to generate nano-sized alumina (Al2O3) particles. It is supposed that the powders have two different roles during milling, firstly, to generate nano-sized Al2O3 by oxidation at the high-energy impact points due to collision between Al and MnO2 particles, and secondly, to keep nano-sized Al2O3 particles physically separate by the presence of coarser particles.

Abstract The aluminum alloy 7075 sheets have drawn more attention in recent years in the automotive industry for lightweighting. Hot stamping of high-strength aluminum alloy has been developed to improve the formability of the part without springback. Obtaining an adequate quench rate is a critical step of the hot stamping process and corresponds to good strength and corrosion resistance. This work looks at measuring the quench rate of 7075 at advanced aging (AA) and T6 condition via two different approaches: forced air and water with various temperatures. The results verify that water is a superior form of quenching, i.e., from 50°C/s to 550°C/s, the forced air-cooled quench rate is 2°C/s-10°C/s. Besides, mechanical properties such as yield strength, ultimate tensile strength, and uniform elongation were measured by tensile testing. As a result, a correlation between the quench rate and final mechanical properties was developed.

Abstract TOC

Abstract Wheel alignment audit systems are used in vehicle service environments to identify vehicles which may benefit from a comprehensive evaluation on a precision static alignment measurement system. Non-contact dynamic wheel alignment audit systems acquire measurement data from vehicles in motion passing between sensors in an inspection lane. The dynamic nature of the moving vehicles introduces variables which are not present when auditing wheel alignment on a static vehicle. Measurement results are affected by changes in vehicle velocity, steering movement, suspension movement, floor surface conditions, tire sidewall profiles, and driver presence, as well as other variables.

Abstract Late-cycle soot oxidation in heavy-duty (HD) diesel engine low-swirl combustion was investigated using single-cylinder engine and spray chamber experiments together with engine combustion simulations. The in-cylinder flow during interactions between adjacent flames (flame-flame events) was shown to have a large impact on late-cycle combustion. To modify the flame-flame flow, a new piston bowl shape with a protrusion (wave) was designed to guide the near-wall flow. This design significantly reduced soot emissions and increased engine thermodynamic efficiency. The wave’s main effect was to enhance late-cycle mixing, as demonstrated by an increase in the apparent rate of heat release after the termination of fuel injection. Combustion simulations showed that the increased mixing is driven by enhanced flow re-circulation, which produces a radial mixing zone (RMZ).

Abstract Cast magnesium (Mg) door inner panels can provide a good combination of weight, functional, manufacturing, and economical requirements. However, several challenges exist including casting technology for thin-wall part design, multi-material incompatibility, and relatively low strength versus steel. A project was supported by the US Department of Energy to design and develop a lightweight frame-under-glass door having a thin-wall, full die-cast, Mg inner panel. This development project is the first of its kind within North America. The 2.0 mm Mg design, through casting process enablers, has met or exceeded all stiffness and side-impact requirements, with significant mass reduction and part consolidation. In addition, a corrosion mitigation strategy has been established using industry-accepted galvanic isolation methods and coating technologies. The performance of the Mg design has been demonstrated through component and vehicle tests.

Abstract AA7075 is susceptible to localized corrosion like exfoliation corrosion (EXCO), intergranular corrosion (IGC), and stress corrosion cracking (SCC). Its susceptibility is strongly affected by heat treatments. In this study, the effects of two heat treatments applied to AA7075 alloy at a different time and temperature on EXCO, IGC, and SCC were investigated. Furthermore, a joining corrosion evaluation using self-piercing riveting (SPR) was conducted. It was concluded that, when compared to the traditional T6 aging process, the samples subjected to a novel advanced aging process with a significantly reduced aging time were comparable with respect to the resistance to EXCO, IGC, SCC, and SPR joining corrosion.

Abstract Tribological properties determine the elemental factors influencing the performance of the components that are subjected to relative motion. Of late, low-density Metal Matrix Composites (MMCs) have been renowned as materials for the components that are subjected to tribological applications. This work reports an experimental study of wear and corrosion behavior of Aluminum Metal Matrix Composites (AMMCs) reinforced with in situ TiB2 particles. These composites were synthesized by a mixed salt route procedure using K2TiF6 and KBF4 at a temperature of 850°C by using the stir casting method. Dry sliding wear behavior of AA5754-TiB2 in situ composites were compared with base material for the various loads, sliding speed, and sliding distances. These parameters were analyzed using Taguchi techniques. It was found that the percentage of reinforcement and load are the most significant parameters.

Abstract The increasingly important need to design simpler structures, reducing the number of constituent components, has motivated the approach outlined in this article, which proposes an effective reengineering example of a product belonging to the automotive industry, combining the advantages offered by the compliant mechanisms with production opportunities linked to the use of additive manufacturing. Taking advantage of compliant mechanisms makes it possible to significantly improve the component’s production phase, leading to undoubted benefits on the supply chain and on product’s time to market, benefits made possible by exploiting the outstanding characteristic of additive manufacturing to produce already assembled multi-material structures.

Abstract The Magic Formula (MF) Tire Model has received wide acclaim for vehicle dynamic simulations. However, it requires that the model parameters be determined for a particular tire, which in turn is a difficult task due to the large number of parameters involved. This work presents a study on the use of a Cascading Algorithm for determining the MF parameters, which is later packaged as a parameter estimation tool. Extending findings from previous research, the cascading algorithm aims to combine the strengths of both the Genetic Algorithm and Nelder-Mead Simplex (NMS) algorithm for the tire model fitting process. The algorithm performance is evaluated based on a total of 456 test datasets of six tires from four different manufacturers. The results show good fitting capabilities (86.5% of the fits have a coefficient of determination greater than 0.9) along with capturing the data trends accurately.

Abstract The issue of material compatibility of biodiesel has been discussed by few researchers but the reported corrosion rates were alarmingly high. This study addresses the corrosion issue of biodiesel with automotive materials with a different but systematic approach following SAE J1747 standard. In earlier studies while conducting material compatibility studies with biodiesel, mention of any specific standard/s has not been generally observed. Earlier studies were conducted by storing the samples for a long time without any change of fuel. However in actual automotive application, change of fuel is always on a periodic basis due to consumption of fuel and the SAE standard recommends for the same. This difference has a significant effect on the material compatibility as this periodic change does not result in making the fuel particularly biodiesel more acidic which is otherwise when stored for a long time during the test period.

Abstract During diesel engine operation, some fuel is entrained in engine oil, particularly as a consequence of strategies to regenerate NOx traps or particle filters. This “fuel dilution” of oil can adversely affect engine oil properties and performance. Compared to diesel fuel, biodiesel is more prone to fuel dilution and more susceptible to oxidation. Oxidation stability experiments were conducted at 160°C using a modified Rapid Small-Scale Oxidation Test (RSSOT) and a Rancimat instrument with 0, 5, 10, and 20 wt% biodiesel in four fully formulated engine oils, two partially formulated engine oils, and two base oils. These experiments showed decreasing oxidation stability with increasing biodiesel content. An exception was noted with the least stable oils (two base oils and one engine oil) in which 5 wt% biodiesel improved the oxidation stability relative to oil without biodiesel.

Abstract The appearance of an automobile is anything but unimportant for the owner. This applies to the acquisition as well as the keeping. In this context, the avoidance of corrosion is a fundamental part of the user’s satisfaction of a company. The body design can be modified to optimize drainage and reduce the risk of corrosion, improving the owner’s satisfaction with the purchase of the automobile. During the proof of concept of water management, as part of the process of development, physical prototypes are state of the art. At this point in the development process, every necessary change is expensive and time consuming. Virtual methods are able to support the development in earlier steps and thus reduce costs. The conventional Computational Fluid Dynamics (CFD) methods could not handle the simulation of a full car in the rain or water passage properly due to much higher computation efforts and deviations from the experiments.

Abstract Although several methods exist for measuring the performance capability of a vehicle, many require detailed knowledge of the forces acting at each tire contact patch or do not account for both the vehicle dynamics and the road geometry. A simple vehicle model is proposed to estimate the upper limit of performance capability for a given operating condition (the Performance Envelope) based on the Effective Friction and the road geometry (slope and cross-slope). The Effective Friction accounts for both the vehicle dynamics and road surface properties and is estimated, through simulation or experimentation, using two standard vehicle dynamics tests: constant radius cornering and straight-line braking. The Performance Margin is defined as the additional performance capability available before the vehicle reaches the Performance Envelope, both represented in the intuitive units of gravity.

Abstract Letter from the Editor

Abstract Tin sulfides (SnS and SnS2), represent a safer and greener alternative to other metal sulfides such as copper sulfides, and MoS2 etc. Their behavior is usually associated to that of solid lubricants such as graphite. A mixture of tin sulfides, with the 65 wt% of SnS2, has been characterized by scanning electron microscopy and by thermal gravimetric analysis (TGA). In order to investigate the effect of tin sulfides upon two crucial friction material ingredients, two mixtures were prepared: the former was made by mixing tin sulfides with a natural flake graphite and the latter was made mixing tin sulfides with a straight novolak. They were analyzed by TGA and differential thermal analysis (DTA) in both nitrogen and air. Some interferences were detected between tin sulfides and graphite in air.