Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H1/00—Contacts
  • H01H1/02—Contacts characterised by the material thereof
  • H01H1/021—Composite material
  • H01H1/023—Composite material having a noble metal as the basic material
  • H01H1/0237—Composite material having a noble metal as the basic material and containing oxides
  • H01H1/02372—Composite material having a noble metal as the basic material and containing oxides containing as major components one or more oxides of the following elements only: Cd, Sn, Zn, In, Bi, Sb or Te
  • H01H1/02376—Composite material having a noble metal as the basic material and containing oxides containing as major components one or more oxides of the following elements only: Cd, Sn, Zn, In, Bi, Sb or Te containing as major component SnO2
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F9/00—Making metallic powder or suspensions thereof
  • B22F9/02—Making metallic powder or suspensions thereof using physical processes
  • B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
  • B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
  • B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
  • B22F2009/0824—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid with a specific atomising fluid
  • B22F2009/0828—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid with a specific atomising fluid with water
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
  • B22F2998/10—Processes characterised by the sequence of their steps

Definitions

• the invention relates to a contact material for low-voltage switching devices in energy technology made of AgSnO, Bi, O, CuO and to an associated method for producing contact pieces from this material.
• contact materials based on AgCdO with Cd0 as the main active component have proven to be particularly advantageous. These contact materials show a small erosion in the arc, a low welding force and a low heating with continuous current supply.
• a contact material which, by oxidation of a plated alloy sheet with 3 to 15 wt.% Tin, 0.01 to 1 wt.% Bismuth and 0.1 to 8.5 wt.% Cu is made.
• an electrical contact material based on silver metal oxide is known from DE-A-2754335, in which 1.5 to 6% by weight bismuth oxide and 0.1 to 6% by weight tin oxide, based on the total amount of oxide, should be present .
• copper oxide or zinc oxide can also be present, but bismuth oxide and tin oxide always dominate and are of the same order of magnitude.
• the invention has for its object to design the known AgSnO, Bi, 0, CuO materials such that the production of contact pieces can be done economically.
• the object is achieved in that the material is a sintered material produced by powder metallurgy from an internally oxidized alloy powder.
• the total metal oxide content of SnO 2 , Bi, O and Cu0 is preferably between 10 and 25% by volume with a SnO 2 content ⁇ 70% by volume of the total amount of oxide, the total metal oxide content consisting of SnO 2 , Bi, O and CuO , can advantageously be between 15 to 20 vol .-%.
• an alloy powder is produced from an AgSnBiCu alloy of a given composition by pressure atomization with water, after drying a powder fraction ⁇ 200 ⁇ m is sieved and internally oxidized in air, so that a composite powder made of AgSnO 2 Bi 2 O 3 CuO arises from which contact pieces are produced by pressing in a die with 600 MPa, which are sintered at 800 ° C for one hour and further compressed by hot pressing at approx. 650 ° C with 800 MPa. Further sintering at approximately 850 ° C. for one hour and cold compression may preferably follow.
• Example Manufacture of a sintered contact material from AgSnO 2 Bi 2 O 3 CuO and the contact piece.
• An alloy of AgSnBiCu of the specified composition is melted from 90.15% mass content of fine silver grains, 8.05% mass content of tin grains, 0.90% mass content of metallic bismuth as fragments and 0.90% mass content of copper in the form of rods.
• An alloy powder of the same composition is produced therefrom by pressure atomization with water. After drying, the powder fraction of less than 200 ⁇ m is sieved off. This fraction is internally oxidized in air between 500 and 800 ° C., after which a composite powder. from AgSnO 2 Bi 2 O 3 CuO of the composition 87.95% mass content Ag, 9.97% mass content SnO 2 , 0.98% mass content Bi, O and 1.10% mass content Cu0.
• the composite powder can be used to produce contact pieces by pressing in a die with 600 MPa. For secure connection technology by brazing, it is useful to press a second layer of pure silver powder together with the contact layer when pressing the composite powder.
• the contact pieces are sintered at 850 ° C for one hour in air.
• the contact pieces are compacted by hot pressing at 650 ° C with 800 MPa. Further compression and solidification can be achieved by a second sintering at 850 ° C for one hour in air and a subsequent cold compression.
• the contact properties of such contact pieces were measured on a test switch.
• the burn-up values were about 25% better than an extruded AgSnO 2 grade with the same oxide content.
• Fs99.9 values were 50% lower in the welding force values and 10% lower values in the contact resistance.
• the structure of the contact material is very fine and even.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Composite Materials (AREA)
• Materials Engineering (AREA)
• Contacts (AREA)
• Powder Metallurgy (AREA)
• Manufacture Of Switches (AREA)
• Mechanisms For Operating Contacts (AREA)
• Conductive Materials (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Related Parent Applications (1)

Publications (3)

Family

ID=6190546

Family Applications (2)

Family Applications After (1)

Country Status (5)

Cited By (4)

Families Citing this family (10)

Family Cites Families (20)

• 1983
  • 1983-02-10 DE DE19833304637 patent/DE3304637A1/de not_active Withdrawn
• 1984
  • 1984-01-30 EP EP85114864A patent/EP0182386B1/fr not_active Expired - Lifetime
  • 1984-01-30 AT AT85114864T patent/ATE57789T1/de active
  • 1984-01-30 DE DE8585114864T patent/DE3483479D1/de not_active Expired - Lifetime
  • 1984-01-30 DE DE8484100927T patent/DE3461872D1/de not_active Expired
  • 1984-01-30 EP EP84100927A patent/EP0118708B1/fr not_active Expired
  • 1984-01-30 AT AT84100927T patent/ATE24628T1/de not_active IP Right Cessation
  • 1984-02-06 JP JP59019815A patent/JPS59148215A/ja active Granted
• 1986
  • 1986-05-16 US US06/865,932 patent/US4681702A/en not_active Expired - Fee Related

Also Published As

Similar Documents

Legal Events