Silver tungsten and silver tungsten carbide

Material

AgW (direct)

AgW (infiltrated)

AgWC (direct)

(submicron size)

Manufacturing process

presintering and infiltration

liquid phase sintering (direct)

solid phase sintering and repressing

Current grain size of the W or WC :

W

between 6 and 8 μ Ø FSSS

between 3 and 4 μ Ø FSSS

WC

< 2 μ Ø FSSS

< 1 μ Ø FSSS

NB : Please, contact us if the above details do not meet your specific requirements (content %, grain size)
METALOR will define, in cooperation with the customer the manufacturing process according to the final product and the electrical application.

Characteristics

Density (g/cm3)

Hardness HV 10

Conductibility % IACS

Forms available

These electrical contacts are produced by die compacting ; a great variety of shapes is therefore possible.
The most common forms are as follows :

M.C.B. Contact

Industrial circuit – breaker
moving contact

A.C.B.

Typical forms for the solderable face :

Direct sintering

Infiltration

Silver excess

Silver excess

Brazing alloy

Brazing alloys :

  • LAg 15 P

Electrical tests results

These alloys utilize the refractory properties of tungsten (melting point : 3400°C) and tungsten carbide (melting point : 2900°C) : they are able to withstand strong electrical arcs with low erosion and low welding tendency. However, the reduced arc mobility as well as the formation of tungstates and oxides generate resistance and temperature rise. These drawbacks may be compensated by using AgC for the fixed contact, choosing the most appropriate tungsten or tungsten carbide content and grain size, utilizing a stronger magnetic blow-out...

Ex: 150 A, 600V, cos φ : 0.77

  1. fixed contact AgW 50
    moving contact AgW 50
  2. fixed contact AgC 5
    moving contact AgW 50

Applications

Switchgears

  • Thermostats
  • MCB
  • Moving contact for circuit-breakers between 100 and 800 A
  • Moving contact for ACB between 1 000 and 10 000 A
  • Arcing contact for large size contactors

Applications

  • Domestic appliances
  • Distribution of electrical energy
  • Railways
  • Aircraft industry

Others conditions

We manufacture according to our customers' specifications. Our technicians are readily available to discuss contact forms, dimensions and brazing requirements.