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US3864827A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for making an electric contact by powder metallurgy and the resulting contact

Assignee: Siemens AG
•
Filing: 1972-08-24
•
Granted: 1975-02-11
•
Expires: 1992-08-24
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Abstract

Abstract A layer of refractory metal or metal compound powder which is mixed with a low melting temperature metal or metal alloy powder, and a layer of low temperature melting metal or metal alloy powder, are arranged together in the cavity of a compacting die and consolidated together to form an integrated two-layer compact which is thereafter heated above said low temperature but below the refractory powder''s sintering temperature to cause the pores of the compact''s refractory portion to be impregnated with the low temperature melting component while leaving an excess thereof forming a thin layer in the refractory portion. Because the two layers of the compact are consolidated together so that the compact may be moved safely without the layers separating during the heating, the use of a continuous furnace for the heating is commercially practical; and because the refractory portion is not sintered, the finished product''s dimensions can be accurately predetermined by the compacting die cavity dimensions. By heating the compact with its low temperature melting end down and resting on a refractory carrier surface having a plurality of depressions beneath this end, said layer is formed with a smooth exposed surface suitable for soldering or welding to a supporting metal part. Thus, a finished electric contact, for example, may be produced by the two steps of compacting and heating only, having a thick contact layer resistant to arc burning and contact welding trouble and a thin support layer that is solderable or weldable to a metal support or operating element. If the low temperature melting metal powder mixed with refractory powder in the refractory portion of the compact, and the low temperature melting powder in the other portion of the compact, are different metals, the heating of the compact can cause alloying or intersolution of the different metals so that in the final product the low temperature melting component of the product has the same composition throughout.

Inventors

  • 👤 Horst Schreiner
  • 👤 Bernhard Rothkegel

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 13:02
CPC Classifications
H; H01; H01H; H01H1/00; H01H1/02; H01H1/021; H01H1/023; H01H1/0233; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49204; Y10T29/49206; Y10T29/49208; Y10T29/4921; Y10T29/49211; Y10T29/49213; Y10T29/49215

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 189 words
A POWDERED METALLURGY METHOD FOR MAKING A TWO-LAYER CONTACT OR THE LIKE, COMPRISING: A. PROVIDING A FIRST LAYER OF INTERMIXED REFRACTORY METAL OR METAL COMPOUND POWDER AND A LOW TEMPERATURE MELTING METAL POWDER; B. PROVIDING A SECOND LAYER OF LOW TEMPERATURE MELTING METAL POWDER; C. COMPACTING SAID FIRST AND SECOND LAYERS TOGETHER TO FORM A COHERENT TWO-LAYER COMPACT; D. PROVIDING A REFRACTORY SURFACE HAVING A PLURALITY OF DEPRESSIONS ON THE SURFACE THEREOF; E. SUPPORTING SAID CONTACT WITH SAID SECOND LAYER ON SAID REFRACTORY SURFACE WITH SAID PLURALITY OF DEPRESSIONS THEREBENEATH; F. HEATING SAID COMPACT UNDER NON-OXIDIZING CONDITIONS TO A TEMPERATURE ABOVE THE MELTING TEMPERATURE OF SAID LOW TEMPERATURE MELTING METAL TO IMPREGNATE THE PORES OF SAID FIRST LAYER WITH THE METAL OF SAID SECOND LAYER; AND G. THE STEP OF PROVIDING SAID SECOND LAYER INCLUDING PROPORTIONING SAID SECOND LAYER TO PROVIDE SAID CONTACT WITH A VOLUME OF SAID LOW TEMPERATURE MELTING METAL WHICH WILL CAUSE THE FORMATION ON THE BOTTOM OF SAID COMPACT OF A TEMPERATURE MELTING METAL WILL AT LEAST PARTIALLY FILL THE THIN LAYER OF LOW TEMPERATURE METAL AND SUCH THAT SAID LOW PORES IN SAID COMPACT.
Claim 2
Dependent Claim 189 words
A POWDERED METALLURGY METHOD FOR MAKING A TWO-LAYER CONTACT OR THE LIKE, COMPRISING: A. PROVIDING A FIRST LAYER OF INTERMIXED REFRACTORY METAL OR METAL COMPOUND POWDER AND A LOW TEMPERATURE MELTING METAL POWDER; B. PROVIDING A SECOND LAYER OF LOW TEMPERATURE MELTING METAL POWDER; C. COMPACTING SAID FIRST AND SECOND LAYERS TOGETHER TO FORM A COHERENT TWO-LAYER COMPACT; D. PROVIDING A REFRACTORY SURFACE HAVING A PLURALITY OF DEPRESSIONS ON THE SURFACE THEREOF; E. SUPPORTING SAID CONTACT WITH SAID SECOND LAYER ON SAID REFRACTORY SURFACE WITH SAID PLURALITY OF DEPRESSIONS THEREBENEATH; F. HEATING SAID COMPACT UNDER NON-OXIDIZING CONDITIONS TO A TEMPERATURE ABOVE THE MELTING TEMPERATURE OF SAID LOW TEMPERATURE MELTING METAL TO IMPREGNATE THE PORES OF SAID FIRST LAYER WITH THE METAL OF SAID SECOND LAYER; AND G. THE STEP OF PROVIDING SAID SECOND LAYER INCLUDING PROPORTIONING SAID SECOND LAYER TO PROVIDE SAID CONTACT WITH A VOLUME OF SAID LOW TEMPERATURE MELTING METAL WHICH WILL CAUSE THE FORMATION ON THE BOTTOM OF SAID COMPACT OF A TEMPERATURE MELTING METAL WILL AT LEAST PARTIALLY FILL THE THIN LAYER OF LOW TEMPERATURE METAL AND SUCH THAT SAID LOW PORES IN SAID COMPACT.
Claim 3
Dependent Claim 49 words
The method of claim 1 in which said compacting comprises first compacting said first-named layer by pressing a plurality of depressions in the surface thereof and applying thereto said second-named layer and compacting both layers together, whereby said thin layer fills said depressions with a majority of its volume.
Claim 4
Dependent Claim 86 words
The method of claim 1 in which said refractory metal or metal compound powder is selected from the class consisting essentially of powdered tungsten, molybdenum, rhenium, mixtures or alloys thereof, and carbide compounds thereof, and said low temperature melting metal powder mixed therewith is selected from the class consisting essentially of powdered silver, copper and alloys thereof together and with nickel, iron and cobalt, and said metal powder of said second-named layer is selected from the class consisting essentially of powdered silver, copper and alloys thereof.
Claim 5
Dependent Claim 86 words
The method of claim 2 in which said refractory metal or metal compound powder is selected from the class consisting essentially of powdered tungsten, molybdenum, rhenium, mixtures or alloys thereof, and carbide compounds thereof, and said low temperature melting metal powder mixed therewith is selected from the class consisting essentially of powdered silver, copper and alloys thereof together and with nickel, iron and cobalt, and said metal powder of said second-named layer is selected from the class consisting essentially of powdered silver, copper and alloys thereof.

References Cited (Backward Citations)

US2641670A Cited
US2694126A Cited
US3254189A Cited
US3226517A Cited
US3143626A Cited
US3359623A Cited
US3610859A Cited
US3511953A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-02-10 1978-08-12 1979-02-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-02-10 1982-08-12 1983-02-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-02-10 1986-08-12 1987-02-11 $7700.00 Window Closed / Lapsed

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