BRAZING OF BERYLLIUM FOR HIGH-TEMPERATURE SERVICE
By brazing with pure silver, joint strengths of 60% (30,000 psi) that of the base metal were obtained at room temperature. In the temperature range of 700 to 1450 deg F, the joint strength was 80% that of the base metal. Twenty- four hour exposures in this range of temperatures did not affect the room temperature strength, if a continuous interface of silver in the joint was absent prior to exposure. Liquid silver spreads only partially on beryllium, apparently because of the liquid's rapid intergranular penetration. Because of this and the toxicity of beryllium fumes given off during a high-temperature braze, the silver should be preplaced or electroplated on the faces to be joined. Because of the rapid intergranular penetration of liquid silver into beryllium, elimination of the continuous interface of silver is readily accomplished by heat treatment during or after the brazing cycle. Intergranular penetration of silver into beryllium is not deleterious; a two-phase alloy consisting of beryllium primary particles surrounded by a silver matrix is ductile. Successful joints at all temperatures can in fact be made with a beryllium-20% (atomic) silver alloy, as well as with pure silver. (auth)
- Research Organization:
- Avco Corp., Wilmington, Del.
- NSA Number:
- NSA-15-011556
- OSTI ID:
- 4084520
- Journal Information:
- Welding J. (N.Y.), Journal Name: Welding J. (N.Y.) Vol. Vol: 40
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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