An experimental study on evaluation of contact surface damages with an optical cross-section method

概要

論文の詳細を見る
Contact surfaces of mechanical relays and switches are often damaged by arc discharges and/or mechanical wear during switching operations. Conventionally, erosion and transfer characteristics of various contact materials under different load conditions have been mainly studied based on observation and evaluation of contact surfaces after switching operation tests. A further detailed study will become possible if we can observe, and preferably, numerically evaluate a changing process of surface damages (especially, growth of a crater and/or a pip) on contact surfaces during switching operations. For that purpose, an evaluation system of contact surface damages by way of an optical cross-section method is being constructed. In this paper, Ag contacts were operated to break a DC inductive 14V-2A load current for 50,000 operations. During the switching operations, changes in a surface profile of the movable (cathode) electrode (a crater growth process) were observed with the optical cross-section method at every 2000 operations. A surface of the counterpart stationary (anode) electrode (a pip growth process) was also observed with another camera system. From the results, certain changes in both electrode surfaces were able to observed during the switching operations.
2011-11-10