METHOD OF PRODUCING AIRTIGHT CERAMIC-METAL SEAL USING COMPENSATING ELEMENT

摘要

FIELD: chemistry. ^ SUBSTANCE: invention relates to ceramic materials and compounds thereof with metallic articles when making separate units of electrovacuum equipment, used in radio and electronic engineering. The airtight compressed mismatched ceramic-metal seal 'ceramic BK94-1 steel 12X18H10T' is obtained via single-step brazing in a vacuum medium with 'silver-copper' PSr72 system solder by adding an intermediate compensating element made from a titanium alloy. Solder PSr72 is first annealed in a vacuum and clarified in HNO3 solution. The intermediate compensating element made from titanium alloy is prepared by defatting and removing the oxide film with vacuum annealing at temperature 860C. The titanium alloy compensates for the effect of internal destructive compression stress arising in the mismatched joint 'vacuum-tight alumina ceramic BK94-1 - stainless steel 12X18H10T', creates a low-melting eutectic mixture with 'silver-copper' PSr72 system solder at joint temperature in a vacuum. ^ EFFECT: method enables to eliminate labour input for preliminary metal coating the ceramic surface and obtain joints with high mechanical strength and air-tightness of not more than 1ù10-3 mm Hgùl/s while monitoring leakage with a helium leak detector.