| 摘要 |
<p>There is described nickel, cobalt and nickel-cobalt alloy coating compositions having improved hot corrosion resistance. In particular, an improved MCrAlY type alloy coating composition consists essentially of, by weight, approximately 8-30 percent chromium, 5-15 percent aluminum, up to 1 percent reactive metal selected from the group consisting of yttrium, scandium, thorium and the other rare earth elements and 3-12 percent of a noble metal selected from the group consisting of platinum or rhodium, the balance being selected from the group consisting of nickel, cobalt and nickel-cobalt. The alloys of the present invention exhibit markedly improved hot corrosion resistance and are considered particularly useful as coatings on the contemporary superalloys. The inventive alloys are in themselves corrosion resistant and do not depend for their protective effect upon a reaction with the substrate material. In addition, these alloys are uniform throughout their thickness and thus will exhibit their protective properties more continuously and consistently than do the aluminide coatings.</p> |
