Changes

<xr id="fig:Microstructure of a powder metallurgical Ag CdO material"/><!--(Fig. 13.11)--> shows the microstructure of a Ag/CdO contact material after being affected by electrical arcing. In the lower part the starting material structure is visible. In the upper part the de-mixing of the composite material through the effects of the switching arc is clearly demonstrated. This “switching structure” shows in certain areas depletion of metal oxide which increases the probability of contact welding during subsequent make operations. Additional analysis by X-ray probing in a scanning electron microscope (SEM) allows the micro analysis of the elements present in the contact surface region.

<figure id="fig:Microstructure of a powder metallurgical Ag CdO material">

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