| 摘要 |
1312700 Glass-ceramic to metal seals ENGLISH ELECTRIC CO Ltd 1 Oct 1971 [13 Oct 1970] 48569/70 Heading C1M Glass ceramic is sealed to metal or between metal and metal, glass, ceramic or a different glass-ceramic by assembling the metal component and a body of devitrifiable glass, with or without a further component, and simultaneously effecting sealing and devitrification, the glass consisting of, in percentages by weight, SiO 2 64-73; Al 2 O 3 5-14; Li 2 O 10-14; K 2 O 3-6; P 2 O 5 2-3; ZrO 2 0-1; ZnO 0-5, and the heat treatment consisting of heating the assembly, as in a graphite jig, at a rate of from 50‹ to 500‹ C.per minute to a temperature at which the glass is fluid, holding for a period of time not exceeding 30 minutes, and then cooling to room temperature at a rate of from 20‹ to 500‹ C. per minute. Heating and cooling rates are preferably between 100‹ and 200‹ C. per minute and the holding time is 10 minutes. Examples are given for metal to glass-ceramic to metal seals with molybdenum, nickel iron alloy and a Ni-Fe-Co alloy. The coefficients of thermal expansion either match or have a slight mismatch to put the metal or other component under compressive stress.
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