INVESTIGATION OF TRANSIENT RESISTANCE AND ELECTRICAL EROSION OF SERIAL CONTACT PARTS RELAY PKL - 2204
Authors: Berezyuk A. , Vasyuk V. , Vishinskiy O. 
Published: December 2023

In this study, the processes of the occurrence of an electric arc and its duration on the contact details of the PKL-2204 series relay are considered in detail. The patterns of changes in electrical erosion, which is a function of current strength and the number of switchings, were also studied.

A detailed analysis of the process of opening the contact details was carried out based on the voltage oscillogram. Studies have shown that this process can be considered in three main stages. The first stage is marked by the separation of the contact parts, and at the very moment of the break of the working surfaces, there is a sharp jump in voltage from 45 mV to 13.5 V, accompanied by the formation of an electric arc. The second stage, lasting about 3.5 ms, is characterized by the weakening of the current to zero, and the arc is completely extinguished on the oscillogram. The third stage is marked by the appearance of a voltage peak on the oscillogram, which occurs when the arc is extinguished and is caused by the inductance L=240 mH. This analysis helps to better understand the process of contact opening and may have practical applications in the field of electrical engineering and electronics.

Analysis of the results of our research indicates the presence of metals that have high resistance to erosion, regardless of their role as an anode or cathode. Among these metals, we can note nickel, copper, niobium, molybdenum, silver, and others, which show resistance to erosion even when the polarity changes, that is, they are erosion-resistant both at the anode and at the cathode. In particular, among such metals it is worth noting silver, molybdenum and niobium, which demonstrate extraordinary resistance to erosion in various conditions. These results may have important implications for the development of erosion-resistant materials for electronic devices and other applications.

On the basis of the conducted research, it was found that the electroerosion resistance of contact parts made of СрН-10 material depends on several factors, including the current strength, the duration of arc burning, the number of commutations, and the physical and mechanical properties of the contact material.

Research into the microstructure of the material during the current switching process revealed thermal, mechanical, and fatigue failure. During this process, the low-melting component of the cathode material melts and intensively evaporates, which leads to the formation of a dispersed and bumpy surface. The working surface of the anode is covered with finely dispersed silver particles, which are transferred from the cathode through the gaseous or liquid phase. The analysis of the spectra of the surface layers indicates a significant occurrence of nickel on the working surface of the cathode, which confirms the priority of evaporation of silver from the surface of the contact part during current switching.

The study of the effect of chemically active reagents on transient resistance showed that in humid air with a high content of ammonia, hydrogen sulfide, sulfur dioxide, and carbon dioxide, the transient resistance of contact parts increases by 5-7 times.