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US 5,495,231 AGranted
Metallic glass alloys for mechanically resonant marker surveillance systems
AssigneeAlliedSignal Inc.
InventorRyusuke Hasegawa
Life of this patent
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AssigneeAlliedSignal Inc.
InventorRyusuke Hasegawa
Estimating the term…
A glassy metal alloy consists essentially of the formula Co.sub.a Fe.sub.b Ni.sub.c M.sub.d B.sub.e Si.sub.f C.sub.g, where M is selected from molybdenum and "a", "b", "c", "d", "e", "f" and "g" are in atom percent, "a" ranges from about 40 to about 43, "b" ranges from about 35 to about 42 and "c" ranges from 0 to about 5, "d" ranges from 0 to about 3, "e" ranges from about 10 to about 25, "f" ranges from 0 to about 15 and "g" ranges from 0 to about 2. The alloy can be cast by rapid solidification into ribbon or otherwise formed into a marker that is especially suited for use in magneto-mechanically actuated article surveillance systems. Advantageously, the marker is characterized by relatively linear magnetization response in the frequency regime wherein harmonic marker systems operate magnetically. Voltage amplitudes detected for the marker are high, and interference between surveillance systems based on mechanical resonance and harmonic re-radiance is virtually eliminated.
A magnetic metallic glass alloy that is at least about 70% glassy, having a composition consisting essentially of the formula Co.sub.a Fe.sub.b Ni.sub.c M.sub.d B.sub.e Si.sub.f C.sub.g, where M is selected from molybdenum and chromium and "a", "b", "c", "d", "e", "f" and "g" are in atom percent, "a" ranges from about 40 to about 43, "b" ranges from about 35 to about 42 and "c" ranges from 0 to about 5, "d" ranges from 0 to about 3, "e" ranges from about 10 to about 25, "f" ranges from about 0 to about 15 and "g" ranges from 0 to about 2.
In an article surveillance system adapted to detect a signal produced by mechanical resonance of a marker within an applied magnetic field, the improvement wherein said marker comprises at least one strip of ferromagnetic material that is at least about 70% glassy, and has a composition consisting essentially of the formula Co.sub.a Fe.sub.b Ni.sub.c M.sub.d B.sub.e Si.sub.f C.sub.g, where M is selected from molybdenum and chromium and "a", "b", "c", "d", "e", "f" and "g" are in atom percent, "a" ranges from about 40 to about 43, "b" ranges from about 35 to about 42 and "c" ranges from about 0 to about 5, "d" ranges from about 0 to about 3, "e" ranges from about 10 to about 25, "f" ranges from about 0 to about 15 and "g" ranges from about 0 to about 2.
Dependencies are inferred from the claim text.