Tri-nickel aluminide compositions alloyed to overcome hot-short phenomena

Claim 1

A process for preparing a tri-nickel aluminide base alloy having good ductility at intermediate temperatures which comprises providing a melt of an alloy of the following composition [Ni.sub.1-x-y Co.sub.x (Al.sub.1-u-v Q.sub.u R.sub.v).sub.y ].sub.100-a-b M.sub.a B.sub.b wherein: Q is at least one optional macroalloying element selected from the group consisting of silicon, niobium, vanadium, tantalum, and titanium; and u is the sum of the concentrations in which the macroalloying elements are present, R is at least one microalloying element selected from the group consisting of niobium, hafnium, vanadium, magnesium, manganese, molybdenum and zirconium; and v is the sum of the concentrations of all of the microalloying elements present with the proviso that if niobium or vanadium is present in a concentration in excess of 0.08 it is present as a macroalloying element, M is at least one optional fungible alloying element selected from the group consisting of iron and chromium; and the quantity, a, is the sum of the concentration between 0.0 and 15 atomic percent in which the fungible alloying elements are present, said base alloy containing the following ingredients in the following approximate concentration values for the above expression as follows: ______________________________________ Ingredient Concentration Value ______________________________________ nickel 1-x-y 0.555-0.72 cobalt x 0.05-0.20 aluminum 1-u-v 0.52-0.98 at least one v 0.02-0.08 microalloying element at least one optional u 0.0-0.40 macroalloying element the combination of aluminum y 0.23-0.245 and its substituents ______________________________________ said optional macroalloying element, Q, being selected from the group and concentrations as follows: ______________________________________ Concentration Element component of u ______________________________________ silicon 0-0.4 niobium 0-0.28 vanadium 0-0.2 tantalum 0-0.2 titanium 0-0.2 ______________________________________ said aluminide base alloy containing boron, B, in an amount, b, between 0.15 and 0.65 atomic percent, rapidly solidifying the melt by atomization and forming a body having a Ll 2 type crystal structure as a principal phase.