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 substrate; pre-treating the substrate by processing the substrate, depositing a Ni-layer on the substrate, or a combination thereof, to form an activated layer on the surface of the substrate; packing the substrate in a powder mixture containing a permeated master metal, an activator, and filler powder; and heat-treating the packing 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 the activated layer having a high defect concentration. Hence, it is possible to prepare a surface modification coating at a low temperature. The surface modification coating of the present invention can also decrease the interface contact resistance between the bipolar plates and gas diffusion layers.