If the thickness is the same, then electroplating will outperform mechanical plating/galvanizing in corrosion testing such as neutral salt spray (fog). Page 8 of the following design guide from the UK company Anochrome shows some typical results for various processes:
Thanks for the link, it's very informative. From my understanding, mechanical galvanizing offers a thicker coating than electroplating. This leads me to believe that it offers better protection, however since the processes are different I'm not 100% convinced it's really the case. I'm struggling to find anything that actually states one is better than the other.
Mechanical plating can deposit a coating in the range of 8-75 micrometers. When plating to a thickness of approximately 8-12 micrometers, it is competing with electroplating, usually for high strength fasteners and other heat treated components with hardness > 32 HRC, in order to avoid hydrogen embrittlement and delayed fracture. When plating in the range of 40-75 micrometers, it is competing with hot dip galvanizing. The following links provide good descriptions of the process, advantages, etc.:
Mechanical Plating by Paul C. Wynn & Jonathon Timms, Atotech UK Ltd
