Nickel brazed articles

DETAILED DESCRIPTION In accordance with the invention, there is provided a homogeneous, ductile brazing foil useful as a filler metal for a brazed metal article.
The brazing foil is composed of metastable material having at least 50 percent glassy structure, and has a thickness less than about 0.
0025 inch.
It has been found that use of a brazing foil that is flexible, thin and homogeneous, as described above, improves braze joint strength, enhances joining precision and reduces process time.
More specifically, the brazing foil has a thickness of about 0.
0005 to 0.
0014 inch.
Preferably, such foil has a composition consisting essentially of 0 to about 4 atom percent iron, 0 to about 21 atom percent chromium, 0 to about 19 atom percent boron, 0 to about 12 atom percent silicon, 0 to about 22 atom percent phosphorus and the balance essentially nickel and incidental impurities.
In addition to containing the foregoing elements within the above-noted composition ranges, the composition must be such that the total of iron, chromium and nickel ranges from about 76 to 84 atom percent and the total of boron, silicon and phosphorus constitutes the remainder, that is, about 16 to 24 atom percent.
The homogeneous brazing foil of the invention is fabricated by a process which comprises forming a melt of the composition and quenching the melt on a rotating quench wheel at a rate of at least about 10.
sup.
5 .
degree.
C.
/sec.
The filler metal foil is easily fabricable as homogeneous, ductile ribbon, which is useful for brazing as cast.
Advantageously, the metal foil can be stamped into complex shapes to provide braze preforms.
Further, the homogeneous, ductile brazing foil of the invention eliminates the need for binders and pastes that would otherwise form voids and contaminating residues.
Also, the filler material provided by the invention enables alternative brazing processes of stainless steels, e.
g.
, dip brazing in molten salts, to be employed.