HEAT TREATMENT EFFECTS ON THE SURFACE OF INSULATION MATERIAL

摘要

The characteristics of insulating fibers are affected by surface chemicals. The effect of the heat treatment on the surface of insulation material was studied in comparison with the effect in the conductor surface. The use of densitometer readings was found to be useful for the study of oxidization of the superconducting strands and in the removal process of binders on the surface of insulation materials. The oxidization of a copper surface increases with temperature starting at an early stage but chromium plating can prevent this effect until the temperature goes up to 295°C. Although it seems to be necessary to go far beyond 300°C to completely remove the binder, a 290°C heat treatment in air can provide the essential binder removal without damaging the chromium plated conductor. A proper choice in binder makes it's removal possible after the process ofwinding a coil.