An Effect of Co–W Barrier Sublayer on the Functional Characteristics of Au–Ru Contact Coatings

Funding Information: Funding: This work was supported by the Ministry of Education and Science of the Russian Federation in the frame of the state assignment FSSN-2020-0003. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.The performance characteristics (microhardness, porosity, roughness, and transient resistance) of Au–Ru coatings with and without the Co–W alloy barrier sublayer electrodeposited on the surface of contact blades of commercially produced reed switches were investigated. It was found that the barrier sublayer reduces the average roughness of the coatings without significant change in their porosity. The Au–Ru coatings without sublayer exhibited a greater variation in the transient resistance during an increase in the pressing force. The service time of reed switches with the barrier sublayer increased in both testing modes: in low-power (50 mV, 5 µA, 50 Hz) by more than 4 × 106 switching cycles, and in mean-power (12 V, 0.25 A, 50 Hz) by more than 1.8 × 106 switching cycles.publishersversionpublishe

Electrochemical Deposition of Ni–W Crack-Free Coatings

The main features of electrochemical deposition of coatings based on Ni–W binary alloy in the pulse current mode using pyrophosphate electrolytes were studied. Two electrolytes with a pH of 8.7 and 9.5 were used. The deposition was carried out with the current density varying in the range of 0.01–0.1 A·cm−2, and the duty cycle (the relative pulse duration) was changed within the range 20–100%. The surface morphology and elemental and phase composition of the coatings were studied by scanning electron microscopy, energy-dispersive X-ray microanalysis and X-ray diffractometry. The experimental conditions allowing us to achieve the maximum Faradaic efficiency and W content in the coatings were determined. It was found that the pulse current mode enabled the fabrication of crack-free coatings with a thickness greater than 6 μm

Switching Properties of the Contact Coatings Based on Refractory Metals Alloys

Switching the properties of the Ag contact groups of an electromagnetic relay with the electrodeposited Ni-W and Co-W alloy coatings was studied. It is shown that these coatings are able to stabilize the spread of contact resistance within the entire test interval and to increase the service life of Ag contact groups from 2.3 × 106 to 4.5 × 106 commutation cycles. According to our research, the service life of coated contact groups is mainly determined by a change in the surface morphology caused by the electrical erosive transfer of the contact materials and to a lesser extent by the formation of poorly conductive adsorbed hydrocarbon films

The Concept of a Modular Cyberphysical System for the Early Diagnosis of Energy Equipment

We have proposed a concept of the modular cyberphysical system for the early diagnosis of industrial and household power equipment based on the application of approaches and standards of Industry 4.0, in particular the concept of the Internet of Things. The main task of the concept and approaches proposed in this paper is the indirect diagnosis and identification of any power equipment whose basic element is the asynchronous motor, in particular the identification of failures and excessive power consumption. In order to resolve the set tasks, it is proposed to use a modular structure of Smart Box diagnosed devices. Specifically, we demonstrate a model of the modular cyberphysical system using a Smart Box device for the early diagnosis of electric equipment, as well as its information flows. This makes it possible to divide all the technological objects at an enterprise into separate structural units, which could form a part of the information cluster. That reduces the reaction time in a cluster system by 30‒35 % compared to a standard one. In addition, the use of a given type of the system makes it possible to reduce the quantity of specialized equipment to the application of similar power equipment.It is proposed to use as a computational core of a Smart Box device the structure a neuro-fuzzy network, which consists of 5 layers. A special feature of this system is the capability to change the number of terms for input variables in order to improve the quality of identification of induction motors. We have chosen, as informative attributes, the characteristic frequencies, which identify an electric motor in the power grid. Specifically, for the systems with small generating capacity, in order to increase the diagnosed induction motors within a cluster, it is advisable to reduce the input set, for example, to 3‒4 CF.The results of our study, in the form of a model of the modular cyberphysical system could be used to build hardware and software modules for the diagnosis of technological and household electrical equipment. In turn, these modules could be combined into an overall global network of IoT