Electroplating / Coating Line

Selection criteria

Bath chemistry control, current density, thickness uniformity.

Supply chain

Magnet plating lines are built by Chinese surface-treatment equipment makers and run either in-house by magnet makers or by plating subcontractors. Coating type and thickness determine corrosion life; specify salt-spray and PCT requirements in the purchase spec.

Buyer FAQ

Ni-Cu-Ni, zinc or epoxy: which coating should I specify for NdFeB magnets?

Ni-Cu-Ni at 10–20 µm is the general-purpose default with good appearance and wear resistance. Zinc at 5–10 µm is cheaper but less corrosion-resistant. Epoxy at 15–30 µm gives the best salt-spray life and electrical insulation. Zinc and epoxy also bond better with structural adhesives than nickel, which matters for glued rotor magnets.

What salt-spray and PCT requirements should I put in the purchase spec?

Typical neutral salt-spray targets (ISO 9227) are 24–72 h for Ni-Cu-Ni, 12–48 h for zinc and 200 h or more for epoxy, with no red rust. A pressure-cooker test (PCT), commonly 121 °C, 2 atm and 100 % RH for 48–96 h, checks coating adhesion and blistering. State the test duration and the pass criteria explicitly.

How should coating thickness and adhesion be checked?

Measure thickness by XRF or magnetic gauge at defined points, usually the centre of the largest face, because barrel plating builds up more on edges and corners than in the middle. Check nickel adhesion with a thermal-shock or bend test and epoxy adhesion with a cross-cut test (ISO 2409), aiming for class 0–1.

Where it is used