| 摘要 |
Pinhole-free enamel coatings have a dielectric breakdown above 2,500 volts are formed atop a multiperforated metallic substrate by the addition of an inert refractory additive, e.g., silicon dioxide, magnesium oxide, calcium fluoride, etc., to the enamel slurry utilized to coat the substrate. The inert additives comprise between 10 and 35 percent by weight of the enamel frit in the slurry and remain physically unaltered during subsequent firing of the substrate to increase the viscosity of the fired enamel thereby assuring an edge coverage of at least 5 mils for enamel coatings less than 10 mils thick. |
