A simulation of magnetic-field-induced ion motion in vacuum arc deposition for the inner surfaces of a tubular workpiece was performed. An auxiliary magnetic field was set to guide the motion of ions inside a pipe, with different magnetic flux densities and ion emission parameters. The results showed the trajectories, deposition ratio and depth of the ions can be controlled via a magnetic field. Within a certain range, the deposition ratio of the ions increases with magnetic flux density. When the magnetic flux density reached a certain value, both the trajectories and deposition ratio of the ions exhibited an obvious periodicity. The depth at which the ions were deposited decreased as an exponential function of the magnetic flux density and ion emission radius, respectively. With an increase in the emission angle, the deposition depth decreased linearly. A numerical model was proposed to express the distribution of the deposition depth. In addition, the deposition ratio and depth are improved with a magnetic field in an environment with a certain density of neutral gas.

Triboelectrification between a liquid and a solid is a common phenomenon in our daily life and industry. Triboelectric charges generated at liquid/solid interfaces have effects on energy harvesting, triboelectrification-based sensing, interfacial corrosion, wear, lubrication, etc. Knowing the amount of triboelectric charge transfer is very useful for studying the mechanism and controlling these phenomena, in which an accurate method is absolutely necessary to measure the triboelectric charge generated at the solid—liquid interface. Herein, we established a method for measuring the charge transfer between different solids and liquids. An equipment based on the Faraday cup measurement was developed, and the leakage ratio (rl) was quantified through simulation based on an electrostatic field model. Typical experiments were conducted to validate the reliability of the method. This work provides an effective method for charge measurement in triboelectrification research.