Method of boronizing transition metal surfaces

A method of boronizing a transition metal comprising:

• preparing a melt including an alkali metal boron tetrafluoride salt;
• dissolving a boron containing material selected from the group of metal boride compounds consisting of CrB.sub.2, MnB.sub.2, NiB, FeB, ZrB.sub.12 and GdB.sub.6 in said melt;
• and
• immersing said transition metal in said melt at a temperature of no more than 700.degree. C. to form a surface layer on said transition metal containing a transition metal boride.

A method of preparing a current collector structure for a high temperature electrochemical cell employing a molten metal halide salt as electrolyte comprising:

• providing a current collector structure comprising a transition metal substrate;
• providing a melt of alkali metal boron tetraflouride salt including a dissolved boron containing material, said boron containing material selected from the group of metal boride compounds consisting of CrB.sub.2, MnB.sub.2, NiB, FeB, ZrB.sub.12 and GdB.sub.6 ;
• and
• immersing said substrate in said melt, while said melt is at a temperature of less than 700.degree. C., to form a corrosion resistant layer of transition metal boride on the surface of the substrate.