Method for preparing surface modification coating of metal bipolar plates

摘要

A method for preparing a surface modification coating of metal bipolar plates is disclosed, which comprises the following steps: providing a metal substrate; pre-treating the metal substrate by substrate processing, depositing a Ni-based alloy layer on the metal substrate, or the combination thereof to form an activated layer on the surface of the metal substrate; packing the metal substrate in a powder mixture comprising permeated master metal, an activator, and filler powders; heat-treating the metal substrate in the powder mixture to allow the permeated master metal to diffuse into the activated layer and then to form a surface modification coating. The permeation rate of the permeated master metal can be increased due to high defect concentration of the activated layer. Hence, a corrosion-resistant surface modification coating is prepared at a low temperature, and it can decrease the interface contact resistance between the metal bipolar plates and gas diffusion layers.