This report summarizes the information generated since the middle of 1961 on the chemical, physical, and mechanical properties of refractory metals that are coated with oxidation-resistant coatings of advanced-experimental or commercial status. It is a supplement to DMIC Report 162, Coatings for the Protection of Refractory Metals from Oxidation, dated November 24, 1961. Recent data on specific silicide- and aluminide- type coatings for columbium, molybdenum, tantalum, and tungsten and their alloys reflect general advances in coating quality and performance, understanding of the behavior of coated systems, and more complete realization of the problems associated with the use of coated hardware.

Issues for Sept. 1951- include the Bulletin.

The vapor pressure of each of the niobium-zinc compounds was measured as a function of temperature. The kinetics of formation of the niobiumzinc compounds on pure niobium from zinc vapor were investigated, and oxidation tests were made on several coatings applied with zinc vapor. The mechanisms involved and the kinetics of the removal of interstitial impurities from niobium by the niobium-zinc compounds were also studied. Further studies of the effects of alloying elements added to the zinc bath used to coat niobium by the dip process confirmed that small amounts of nickel and aluminum in the proper combination are beneficial. (Author).