copperize
/kəˈpɜrzˌaɪz/Definitions
1. verb
to give a reddish-brown color to something, especially to give a brownish-red color to metals, especially copper
“The metal was copperized to make it suitable for the new design.”
2. noun
the process of giving a reddish-brown color to something, especially to giving a brownish-red color to metals, especially copper
“The copperization of the metal took several days to complete.”