Abstract: Improved Ni, Fe and Co based superalloys having excellent oxidation resistance and weldability. The superalloys are obtained by at least partially replacing the Ni in conventional superalloys with Pd. The alloys may also contain strengtheners and modifiers such as Co, W, Mo, V, Ti, Re, Ta, Nb, C, B, Zr, Y, and Hf. The superalloy has good strength, improved weldability and excellent oxidation resistance suitable for use in many aerospace and power generation turbine applications. A preferred embodiment comprises (in wt %) 1-9% (Al+Ti), 0-0.01% B, 0-0.15% C, 0-25% Co, 5-30% Cr, 0-10% Fe, 0-0.009% (Hf+Y+Sc), 1-15% (Mo+W), 0-8% (Nb+Ta), 40-68% Ni, 4-32% Pd, 0-10% (Re+Rh), 0-5% V, and 0-0.015% Zr.

Abstract: A method for lowering the oxygen potential of an inert processing atmosphere containing a reducing gas such as hydrogen, by introducing a metal catalyst to induce reaction between the reducing gas and oxygen, which may originate from leaks into the system or from other sources. The catalyst, such as a precious metal, increases the rate of reaction between gaseous hydrogen and gaseous oxygen to form water vapor, thereby decreasing the amount of molecular oxygen available to react with oxidizable materials exposed to the inert processing atmosphere.

Abstract: An oxidation resistant alloy comprising about 3 to 14 percent Cr by weight, about 3 to 50 percent by volume Si.sub.3 N.sub.4, and the balance selected from the group consisting of Fe, Ni, Co and alloys of these metals. Preferably, the Cr content is between 8 to 12 percent by weight, the Si.sub.3 N.sub.4 content is between about 3 to 22 percent by volume, and the alloy further includes between 1 to 2 percent Si by weight and between about 0.05 and 0.2 percent by weight of a reactive element.

Abstract: A novel process for enhancing the leaching rate of a mineral wherein the mineral is characterized by the tendency to form a reaction product layer during leaching. A suitable particulate modifier such as carbon is mixed with the mineral prior to leaching and selectively alters the characteristics of the reaction product layer. The process is particularly useful for leaching chalcopyrite, sphalerite and galena.