I've never posted about this here, it's not really new, but it's got a permanent new sale price just in time for your holiday metallic animations. 

[Blender] Medle - Antique And Oxidize Metal Shader

This is a stylized shader node for cycles, with presets that model nearly any kind of metal, antiquing, and oxidation. The node comes with presets for materials like copper, iron, aluminum, and more. It ships with a standard material with loads of configurable settings, and a simplified material for those looking to get started quickly. Included are also sample CC0 textures for oxidation, water leaks, metal wear, and imperfections.

https://cdlegasse.itch.io/blender-medle-shader

If you have any questions feel free to post em here!