A metallized thermoset containing a crosslinked metallized polymer having a backbone having an acetylenic repeat unit and --SiR.sub.2--(O--SiR.sub.2).sub.n-- and/or --SiR.sub.2--(O--SiR.sub.2).sub.n-[Cb-SiR.sub.2--(O--SiR.sub.2).sub.n].su- b.m--. At least one of the acetylenic repeat units contains a (ML.sub.x).sub.y-acetylene complex. The metallized thermoset contains a crosslink between acetylene groups and/or a polycarbosiloxane crosslink. M is a metal, L is a ligand, x and y are positive integers, R is an organic group, Cb is a carborane, and n and m are greater than or equal to zero. A method of making a metallized thermoset by providing a metallized polymer and heating the metallized polymer. The metallized polymer contains the above backbone. Heating the metallized polymer forms crosslinks between acetylene groups and/or polycarbosiloxane crosslinks.