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The increasing popularity of electric vehicles as an alternative to internal combustion engine vehicles brings new realities, challenges and opportunities for scientists and engineers. A key element of this transition will be to develop solutions for lubrication, thermal management, electrical compatibility and corrosion inhibition. Two-dimensional materials are well poised to address these challenges and enhance the performance, efficiency, durability and, hence, sustainability of electric vehicles during this century and beyond.

Up to date, most metalworking fluids (MWFs) are emulsions made of petroleum-derived oil bases and sodium petroleum sulphonate emulsifiers. They are not readily biodegradable, and their waste is hazardous for users and the environment. Therefore, green MWFs are required for achieving cleaner production processes. Recently, various MWFs have been developed using vegetable oil bases to meet biodegradability to some extent. However, the emulsifier has been scarcely replaced by a green product. This research aims to produce and evaluate Pickering emulsions made of Jatropha oil (JO) and partially deacetylated and fibrillated chitin (PDFC) as emulsifiers at different concentrations. JO is a non-edible biodegradable oil with remarkable lubricity properties, while PDFC is produced by extracting chitin from waste heads and shells of the shrimp species Litopenaeus vannameii, followed by partial deacetylation and further fibrillation, which improves wettability and stabilization. The prepared emulsions were characterized in terms of creaming index and size of emulsion droplets and evaluated as MWFs in actual turning operations of AISI 1018 steel bars via minimum quantity lubrication (MQL) technique. The findings suggest PDFC as a potential eco-friendly emulsifier to form green MWFs with acceptable stability generating low cutting forces and significant workpiece finishing and chips quality.

This study aims to assess the compatibility of various e-thermal fluids for immersion cooling in battery electric vehicles through a copper wire resistance corrosion test. The tested fluids include a polyalphaolefin, diester, mineral oil API G-III, transformer oil, and a fully formulated dielectric coolant. The test was conducted at 130 °C for 336 h, and the resistance of the copper wires was monitored in vapor and oil phases. By comparing the resistance variation and analyzing portions of the wires through scanning electron microscopy, it was found that the vapor phase of PAO and diester in one of the tests exhibited significant corrosion, while the dielectric coolant showed minimal corrosive effects, implying better compatibility. These results provide insights into the corrosion behavior and compatibility of the fluids with copper, which are essential for selecting suitable dielectric fluids for immersion cooling applications in electric vehicles.

Electro-mobility is getting an increasing attention and progress around the world. To develop and teach artificial intelligence and automotive engineering focused on autonomous vehicles in an undergraduate level, functional and simple autonomous vehicles/platforms are required. Teaching autonomous driving is a challenging task. Indeed, most existing autonomous driving teaching activities focus on few technologies/components involved. This not only fails to provide a comprehensive coverage, but also sets a high entry barrier for students with different backgrounds. Thus, teaching and learning autonomous vehicle systems, mechatronics and programming can be very challenging for students, especially when combined with robotic vehicle design, construction and testing. The significance of this research is based on two main contributions: one is providing a new reachable and didactic technology for autonomous navigation academic purposes while the second is demonstrating its operation under different didactic and test schemes to illustrate possible practices. The vehicle consists on a full-size automotive traction, steering and braking systems assisted electronically via remote control. In addition, a basic control system was designed and implemented to avoid collision that may be caused by navigation algorithms faults. At an experimental stage, the vehicle was useful to realize basic navigation schemes acceptably.

In this paper, the influence of oxidation of automatic transmission fluids (ATFs) and sliding distance on the friction coefficients of a wet clutch in approached running-in conditions was investigated. The ATFs were oxidized by a laboratory process approaching oxidation occurred in actual ATFs. Oxidation was evaluated by means of increase in carbonyl compounds and depletion of zinc dialkyldithiophosphates (ZDDPs) additives. Also, the changes in kinematic viscosity and viscosity index were evaluated. Pin-on-disk tests were conducted to replicate the actual sliding contact in a wet clutch. The pin specimens were cut from friction material composite plates and the disks were actual steel separators both from an automotive wet clutch. Friction coefficient, μ, was measured at progressive sliding velocity, ν , to obtain μ-ν curves at 26 and 100 ΰC. Three μ-ν tests were consecutively run using the same pair of specimens and oil. The cumulative sliding distance for each μ-ν test generated surface flattening using the oils. The friction coefficients of the wet clutch increased due to the ATFs oxidation meanwhile the d μ /d υ values decreased in most cases. It suggests that ATF oxidation can enhance torque capacity of the wet clutch, but it could reduce anti-shudder property. Progressive sliding distance improved the slopes in the μ-ν results using fresh ATFs meanwhile it generated a slope decrease by using aged ATFs.

This study aims to investigate the effect of the presence of a simulated corrosive body fluid (Hank’s solution) on the micro-abrasion and corrosion resistance of two borided biomedical alloys (AISI 316L stainless steel and ASTM F1537 CoCrMo alloy) when in sliding contact with a ceramic countersurface. The materials were subjected to a powder-pack boriding treatment. The modified surfaces were characterized mechanically and physico-chemically. The changes of wear resistance of both borided alloys were determined by means of micro-abrasion tests using a slurry made of the corrosive solution with F-1200 SiC abrasive particles. 25-mm-diameter dielectric glass balls were used as countersurface in the wear tests with the twofold purpose of replicating a ceramic-on-ceramic biomedical contact and avoiding the effect of galvanic corrosion with the metallic samples to be tested. The tests were run in triplicated at 0.1, 0.2 and 0.5N of applied load at constant sliding distance and speed. The wear volumes and wear scar examination were carried out by optical profilometry and microscopy. On the other hand, the corrosion resistance of the materials (before and after boriding treatment) was characterized by potentiodynamic polarization measurements in a closed three-electrode cell using the corrosive fluid. According to the results found, the hardness of the alloys increased significantly between 300 and 400% by boriding. However, the micro-abrasion/corrosion situation was detrimental for both alloys under sliding with the ceramic countersurface in the presence of Hank’s solution, which is opposite to that reported in literature for other abrasion–corrosion conditions investigated.

This work aims to characterize and compare the coefficient of friction (CoF) and wear rates of some metallic materials (AISI 6061-T6 alloy, AISI 316 L stainless steel and ASTM F1537 CoCrMo alloy) under different wear modes, namely, micro-abrasion abrasion (rolling and mixed rolling/grooving abrasion), and wet and dry sliding abrasion. The wear modes were achieved by conducting testing under muddy environment at different SiC abrasive particles concentration and wet and dry conditions at three different loads (1, 2 and 3 N) using an instrumented micro-abrasion tester. Wear volumes were measured by optical profilometry to estimate wear rates, while wear patterns were visualized in detail by SEM. CoF, wear rate and mode results for all materials and conditions are reported and discussed. Wear modes were found to have a considerable effect on CoF and wear rate for the materials. Pure rolling abrasion generated the highest wear rates for all materials. Mixed rolling abrasion/grooving produced higher CoFs, but lower wear rates than those produced by pure rolling abrasion. Wet sliding promoted the highest CoFs for AISI 316L SS and AISI 6061-T6 meanwhile dry sliding generated the lowest CoFs and wear rates.

Electric Vehicle Fluid Testing edited by Leonardo Israel Farfan Cabrera, Peter Lee and Ali Erdemir is reviewed.