The Collaborative International Dictionary of English v.0.48:

Metallize \Met"al*lize\, v. t. [imp. & p. p. Metallized; p.
   pr. & vb. n. Metallizing.] [Cf. F. m['e]talliser.]
   To impart metallic properties to; to impregnate with a metal.
   [R.]
   [1913 Webster]