SCALING OF ZIRCONIUM AND ZIRCONIUM ALLOYS. Technical Progress Report No. 1

Zirconium-base binary alloys were prepared using the elements Mo, Fe, Co, Cr, Ni. Cu, Ag, Ta, Nb, Bt. Pa, Os, Ir, Rh, Ru, V, Si, Mn, Sn, Pb, W, Sb, Ge, Al, Ti, Mg, Zn, La, and Ba. Also, Zr-base ternary alloys were prepared using the elements Cu, Ni, Nb, Ta, V, Sn, Sb, and W. The maximum total alloy content of the alloys was five per cent. The Zr used was low-Hf sponge,and the alloys were prepared-by arc melting in an Ar atmosphere. The alloys were tested for scaling resistance at the temperatures 1200, 1500, and 1800 deg F in a multi-specimen furnace for periods up to about 300 hours. Scaling Propensity of the alloys was evaluated on the basis of the weight increase per unit area as compared to that of unalloyed Zr. The binary alloys containing Ni and Cu showed the greatest scaling resistance of all the binary alloys at all temperatures. Ternary alloys showed little or no improvement over the most scaling resistant binary alloys. The number of alloys more resistant than unalloyed Zr was about the same at 1200 and 1500 deg F, but was considerably more at 1800 deg F. In general, there was some change in the order of relative scaling propensity based on the average weight increase per average. unit area per hour at the three temperatures. A logarithmic plot of weight increase versus time for most of the alloys showed a sharp increase in the scaling rate after various periods of time, whereas very few showed a decrease. (auth)