AL 718
AL 718 Technical Data
Uses
Used for a variety of applications including brazing electronic vacuum tube assemblies. Common base materials joined include copper, nickel, metalized ceramics, nickel-cobalt-iron, and carbide.
Brazing Characteristics
AL 718 (or BAlSi-4) is a low melting general purpose aluminum alloy with a narrow freezing range. AL 718’s silicon content provides for increased fluidity and reduced shrinkage. AL 718 produces bright and almost smut free welds. Hot cracking is reduced when this alloy is used.
Properties of Brazed Joints
The properties of a brazed joint are dependent upon numerous factors including base metal properties, joint design, metallurgical interaction between the base metal and the filler metal. Joint clearances of 0.003-0.005 in. (.076-.127mm) per side are optimum for achieving highest joint strength. Joints with increased clearances can still produce adequate joint strengths depending on final operating conditions.
Specifications
AL 718 alloy conforms to: Aluminum Association (AA) 4047, American Welding Society (AWS) A5.8/A5.8M BAlSi-4, Aerospace Material Specifications (AMS) 4185
Available Forms
Wire, strip, engineered preforms, specialty preforms per customer specification, powder and paste.
Compare With
- AMS: 4185
- AWS: BAlSi-4
- Lucas: Al 718
- UNS: A94047
Specifications
- Brazing Temperature Range High: 1120 F / 604 C
- Brazing Temperature Range Low: 1080 F / 582 C
- Liquidus: 1080 F / 582 C
- Solidus: 1070 F / 577 C
Composition
- Al: 86.45%
- Si: 12%
- Fe: 0.8%
- Cu: 0.3%
- Zn: 0.2%
- Mn: 0.15%
- Mg: 0.1%
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