| 摘要 |
1,136,336. Enamel or glass and metal mixtures. TRW Inc. 17 Jan., 1967 [1 Feb., 1966], No. 2497/67. Heading C1M. A vitreous enamel electrical resistor composition adapted for application to and firing on a substrate as a film consists of 50% to 95% by volume of glass frit and 50% to 5% by volume of a mixture of finely divided particles of a refractory metal nitride and finely divided particles of a refractory metal. The refractory metal may be titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, tungsten or molybdenum and the nitride a nitride of any of these. Any of the refractory metals may be used with its own nitride or a nitride of any of the others. The ratio of metal nitride to metal may be between 0À5 to 5 parts metal nitride to 1 part metal. The glass frits are preferably the borosilicate frits such as lead, bismuth, cadmium, barium, calcium or other alkaline earth borosilicate frits. To make the resistance material the glass frit, metal nitride and metal are broken down to particles below 2 microns in size and mixed together such as by ball milling in water or butyl carbitol acetate or a mixture of butyl carbitol acetate and toluol. The mixture is then adjusted to the correct viscosity for application to the substrate which is generally of ceramic such as glass, porcelain, steatite, barium titanate or alumina &c., by brushing, dipping, spraying, or screen stencil application. The coated substrate is fired in a conventional furnace preferably in an inert or reducing atmosphere. Small quantitites of clay may be added to the coating mixture to increase the firing temperature and thus give a greater resistance stability. |
