Examination of commercial ceramic coatings for the electrical insulation of Bi-2212 wire

In the last twenty years, a number of studies have been dedicated to the development of thin ceramic coating for the electrical insulation of Ag-sheathed Bi-2212 wires. Instead of preparing a coating by mixing different compounds in house, this technical note examines if commercial acrylic coatings containing TiO2 particles (white paints) could be used to form TiO2 coating on Ag-sheathed Bi-2212 wires. The compatibility of the acrylic coating with the heat treatment of Ag-sheathed Bi-2212 wire was verified by measuring the effect of coating on the critical current. It was found that the critical current is almost unaffected by the presence of the coating. The acrylic coating characteristics (for example drying time versus temperature and coating thickness at different dip coating speed) were studied and used to prepare a reel-to-reel system for coating long wires.