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Solder and brazing alloys having improved properties and method of preparation

Assignee: CINCINNATI A CORP OF OH, University of
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Filing: 1990-03-22
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Granted: 1992-03-10
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Expires: 2010-03-22
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Abstract

Abstract A solder or brazing alloy having improved properties by reason of the presence of at least one uniformly dispersed non-acicular and non-dendritic intermetallic phase having a particle size of about 1 to 25 microns. A method of preparing the alloy comprises melting the alloy at a temperature sufficient to melt the intermetallic phase or phases, cooling to a semi-solid state, subjecting the semi-solid alloy to vigorous shearing and/or vibration at the solid-liquid interface, and solidifying the alloy.

Inventors

  • 👤 Jainagesh A. Sekhar

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 17:33
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; C; C22; C22C; C22C1/00; C22C1/02

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 103 words
A method of improving the properties of solder and brazing alloys which contain at least one coarse, acicular and/or dendritic intermetallic phase having a higher melting temperature than that of the matrix alloy, which comprises melting said solder or brazing alloy at a temperature sufficient to melt said at least one intermetallic phase, cooling said alloy to a semi-solid state, subjecting the semi-solid alloy to vigorous shearing and/or vibration at the solid-liquid interface while in said semi-solid state, and solidifying said alloy whereby to obtain a microstructure wherein said at least one intermetallic phase is present as a fine, non-acicular and non-dendritic structure.
Claim 2
Independent Claim 103 words
A method of improving the properties of solder and brazing alloys which contain at least one coarse, acicular and/or dendritic intermetallic phase having a higher melting temperature than that of the matrix alloy, which comprises melting said solder or brazing alloy at a temperature sufficient to melt said at least one intermetallic phase, cooling said alloy to a semi-solid state, subjecting the semi-solid alloy to vigorous shearing and/or vibration at the solid-liquid interface while in said semi-solid state, and solidifying said alloy whereby to obtain a microstructure wherein said at least one intermetallic phase is present as a fine, non-acicular and non-dendritic structure.
Claim 3
Dependent Claim 29 words
The method of claim 1, wherein said vigorous shearing involves an amount of shear greater than 1000% and a rate of shear greater than 0.5 to 1 mm/mm sec.
Claim 4
Dependent Claim 26 words
The method of claim 1, wherein said alloy is chosen from the group consisting of tin--copper, silver--copper--phosphorus, silver--zinc, silver--tin, silver--copper--tin, tin--antimony, silicon--aluminum, magnesium--aluminum, indium--tin, and bismuth--lead.
Claim 5
Dependent Claim 43 words
A solder alloy containing at least one intermetallic phase, produced by the method of claim 1, wherein said at least one intermetallic phase is in the form of uniformly dispersed non-acicular and non-dendritic particles having a size of about 1 to 25 microns.
Claim 6
Dependent Claim 36 words
The method of claim 3, wherein said alloy is a tin--copper system containing about 4% copper and balance tin aside from incidental impurities, and wherein said alloy is melted at a temperature above about 415° C.
Claim 7
Dependent Claim 37 words
The method of claim 3, wherein said alloy is a tin--silver system containing about 10% silver and balance tin aside from incidental impurities, and wherein said alloy is melted at a temperature of at least 310° C.

References Cited (Backward Citations)

US3146097A Cited
US3284192A Cited
US3599319A Cited
JPS55141536A Cited
SU881129A1 Cited
JPS58100643A Cited
JPS60159117A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-03-10 1995-09-09 1996-03-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-03-10 1999-09-09 2000-03-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-03-10 2003-09-09 2004-03-10 $7700.00 Window Closed / Lapsed

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