Dr. Kubitz GmbH

Oberflächentechnik

Electrodeposited hardmagnetic cobalt layers for length and angle encoders

Examples for cobalt coatings

Our range now includes electrodeposited magnetic cobalt, a novel coating developed in conjunction with the Ilmenau Technical University for use in magnetic measuring and positioning systems. The hard magnetic cobalt (patent pending) will carry magnetically stored positioning information as required in automatic linear and angular measurement. This function has up to now been performed by magnetic strip fixed by adhesion which is vulnerable to external influences. Hard magnetic layers that have been deposited by our electrolytic method are integral with the substrate and infinitely more robust.

Advantages

  • Magnetic coating integral with the substrate material; no adhesion processes required
  • No joint to cause a jolt on circular scales used for angular measurement
  • Hight resistance to dirt, oil and organic solvents
  • Materials of many types can be coated: aluminium, steel, ceramics, etc.
  • The magnetic properties can be set by the choice of deposition parameters

Applications in precision engineering

  • Systems for measuring length with linear encoding applied; magnetic layers on bars or girders
  • Systems for measuring angles with circular encoding applied; magnetic coating on the axial or radial surfaces of cylinders
  • Tailor-made encoding of substrates either with one or with more than one track

Typical magnetic and structural properties

  • High coercive fields (40–110 kA/m), which increase the resistance of the magnetically stored information to external magnetic influence
  • High remanence figures (10–40 per cent of the saturation magnetism of cobalt)
  • Particulate structure of the magnetic deposit (magnetic particles of cobalt kept separate by a non-magnetic matrix) as source of the hard magnetic properties
  • Low dependence of the characteristic magnetic values on the thickness of coating
  • Large range of possible coating thicknesses to permit the signal from the magnetic layer to be adjusted to a range of magnetoresistive sensors
Dr. Kubitz GmbH Oberflächentechnik • http://www.kubitz-galvano.de