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We demonstrate that the cold flowability of the waxy crude oil can be significantly improved via electrical treatment. A novel apparatus was assembled to electrically treat the waxy crude oil while simultaneously measuring its rheological properties. A method was developed to calculate the oil’s viscosity by using non-Newtonian fluid mechanics and rheological principles. Lower treatment temperatures, higher electric field strengths, and lower shear rates provided greater viscosity reduction. Notably, a viscosity reduction of 70% was obtained when the oil was electrically treated near its pour point for 90 s. Microscopic examinations indicate that the broader size distribution of wax particles in the treated oil might be responsible for the observed viscosity reduction. Besides, the energy consumption of the electrical treatment was estimated to be less than 1% of that of the conventional heating method to achieve the same viscosity reduction performance.

This study demonstrates that magnetron-sputtered NbSe2 film can be used as a lubricant for space current-carrying sliding contact, which accommodates both metal-like conductivity and MoS2-like lubricity. Deposition at low pressure and low energy is performed to avoid the generation of the interference phase of NbSe3. The composition, microstructure, and properties of the NbSe2 films are further tailored by controlling the sputtering current. At an appropriate current, the film changed from amorphous to crystalline, maintained a dense structure, and exhibited excellent comprehensive properties. Compared to the currently available electrical contact lubricating materials, the NbSe2 film exhibits a significant advantage under the combined vacuum and current-carrying conditions. The friction coefficient decreases from 0.25 to 0.02, the wear life increases more than seven times, and the electric noise reduces approximately 50%.

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In order to improve the cutting performance in broaching, the lubrication and cleaning effects offered by water-based cutting fluids with green additives need to be studied from the viewpoint of green manufacturing. Therefore, water-based solutions with castor oil, surfactant (linear alkylbenzene sulfonate, LAS), and nanographite were prepared by ultrasonic agitation and sprayed into the zone of broaching via atomization. The performances of the cutting fluids, in terms of the viscosity, specific heat, wetting angle, and droplet size, were evaluated to discuss their effects on the broaching load. Among the fluids, the addition of LAS into oil-in-water (WO-S), where its cutting fluid with 10 wt.% castor oil and 1.5 wt.% surfactant, exhibited the lowest broaching force. With regard to the lubricating and cleaning mechanisms, WO-S has good wettability and permeability, and hence, can lubricate the cutting edge of the tool to decrease the cutting load, cool the cutting edge to keep it sturdy, and clean the surface of the cutting edge to keep it sharp. The results reveal that the simultaneous addition of castor oil and LAS had remarkable effects on the lubrication and cleaning, and resulted in a broaching load reduction of more than 10% compared to commercial cutting fluids. However, the addition of nanographite could not improve the lubrication owing to its agglomeration.