DEMARTIN electroless nickel diamond DIADEM® Grip

DEMARTIN electroless nickel diamond DIADEM® Grip

Download PDF


General

DIADEM® GRIP coatings utilise the possibility of specifically increasing the friction coefficients of a surface by incorporating hard material particles (preferably diamond). This is advantageously achieved with electroless nickel coatings, in which diamond particles with an average grain size of 10, 25 or 35 µm are embedded, depending on the application. The nickel layer is so thin that about half of the embedded diamonds protrude from the layer. Under the effect of the preload force, the diamond particles penetrate into the mating body and create a micro-form fit.
In the case of friction-locked connections, the limits of the transfer capability are defined by the adhesion coefficient, which is approx. µ = 0.15 for the steel material pairing under practical conditions and high surface pressures (p>50MPa). A DIADEM® GRIP coating increases the coefficient of static friction and thus the torque that can be transmitted by a force-fit by a factor of 2-4.

    Layer properties

    - Increase in the coefficient of adhesion by up to 400 %

    - Reliable transmission of maximum forces and torques

    - Improvement of the overall state of tension

    - Thin oil films on component surfaces do not affect the coating function

    - Highest degree of safety and reproducibility

    - Direct coating, film or intermediate elements according to customer specification

    - Avoidance of fretting corrosion; cold welding

    - Good corrosion resistance

    - RoHS - Compliant

    Application requirements

    The performance of a DIADEM®Grip coating is decisively determined by the condition of the surfaces involved. Higher surface roughness requires larger diamond particles in order to create a reliable micro-mould closure. This is taken into account by the DIADEM®Grip variants listed below.

    DIADEM®GRIP 10

    • Roughness depth Rz component surfaces: < 5.0 µm
    • Ra component surfaces: < 1.0 µm
    • Wave depth W: < Rz


    DIADEM®GRIP 25

    • Roughness depth Rz component surfaces: < 12.5 µm
    • Ra component surfaces: < 2.5 µm
    • Wave depth W: < Rz


    DIADEM®GRIP 35

    • Roughness depth Rz component surfaces: < 17.0 µm
    • Ra component surfaces: < 3.5 µm
    • Wave depth W: < Rz
    • Surface pressure: > 50 MPa
    • Application temperature: < 400 °C

    Physical properties

    DIADEM®GRIP 10

    - Average diamond grain size 10 µm

    - Layer thickness 5 - 9 µm

    - Total layer thickness 10 - 22 µm

    - Diamond surface coverage 8 - 35 %


    DIADEM®GRIP 25

    - Average diamond grain size 25 µm

    - Layer thickness 13 - 17 µm

    - Total layer thickness 30 - 45 µm

    - Diamond surface coverage 8 - 35 %


    DIADEM®GRIP 35

    - Average diamond grain size 35 µm

    - Layer thickness 14 - 22 µm

    - Total layer thickness 40 - 55 µm

    - Diamond surface coverage 10 - 40 %

    - Coating colour metallic silvery grey

    - Coating hardness nickel-phosphorus layer 400 - 600 HV 0.1

    Applications

    - Automotive industry :

    Safe torque transmission in combustion engines and electric motors

    Connection technology in the chassis area

    - Drive technology

    - Mechanical engineering

    - Wind and hydroelectric power plants

    - Energy and electrical engineering

    Coatable materials

    • Steel (hardened, plasma-nitrided, boronised)
    • Stainless steel
    • Nickel and nickel alloys
    • Copper and copper alloys
    • Aluminium and aluminium alloys

    Component sizes

    • Component sizes:                                               up to 30 kg weight

                                                                                  500 * 350 mm

    Processing options

    • Decoating and recoating of components is possible