Abstract: A method for achieving both improved strength and improved ductility in intermediate phases is provided. The method, briefly stated, comprises the steps of providing a melt whose composition substantially corresponds to that of a preselected intermetallic phase having a crystal structure of the Ll.sub.2 type, such as nickel alumininde, modified with from about 0.01 to 2.5 atomic percent boron, and modified further with cobalt substituent metal and rapidly solidifying the melt at a cooling rate of at least about 10.sup.3 .degree. C./second to form a solid body, the principal phase of which is of the Ll.sub.2 type crystal structure in either its ordered or disordered state.

Abstract: New .gamma.' strengthened nickel-base superalloy compositions are described that, when forged and properly heat treated, demonstrate superior resistance to fatigue crack growth accompanied by very good high temperature properties. Parts can be fabricated (e.g., using conventional cast and wrought processing) from these alloys without encountering difficulty in forging.

Abstract: Improvements in the positive temperature dependence of yield strength and in the work hardening rate of tri-nickel aluminide base alloys are achieved. The novel alloy composition has seven alloying ingredients as follows:______________________________________ Concentration Ingredient in Atomic % ______________________________________ Ni balance Co 8-12 Al 16-20 Si 4-6 Nb 0.26-0.30 Zr 0.02-0.04 B 0.2-0.7 ______________________________________The novel composition may be prepared by forming a melt of the composition and atomizing the melt with an inert gas to form fine particles with Ll.sub.2 type crystal structure. The powder is densified by heat and pressure to a novel alloy composition having the improvements in positive temperature dependence of yield strength and work hardening rate as noted above.

Abstract: A substantial increase in strength of a boron doped nickel aluminide is achieved by employing a substituent metal in the Ni.sub.3 Al composition to replace a part of the aluminum. Vanadium and silicon are successfully substituted for a portion of the aluminum to provide a composition:(Ni.sub.0.75 Al.sub.0.20 X.sub.0.05).sub.99 B.sub.1where X is selected from the group consisting of vanadium or silicon.

Abstract: A metal body having high tensile strength and ductility at temperatures over 1000.degree. F. is provided. The body is prepared by hot isostatic pressing of powder formed by atomization of a melt of an alloy. The alloy composition base is according to the formula:(Ni.sub.1-x Al.sub.x).sub.100-y B.sub.ywhere x is between 0.23 and 0.25, and where y is 0.1 to 2.0.The consolidated body is suitable for machining and may be annealed for a couple of hours at temperatures between 800.degree. C. and 1200.degree. C. following such machining.

Abstract: A metal body having high tensile strength and ductility at temperatures over 1000.degree. F. is provided. The body is prepared by hot isostatic pressing of powder formed by atomization of a melt of an alloy. The alloy composition is according to the formula(Ni.sub.1-x-z Co.sub.x Al.sub.z).sub.100-y B.sub.ywherein x is at least 0.05, andwherein y is 0.10 to 2.0, andwherein z is 0.23 to 0.25.The consolidated body is suitable for machining to final dimensions. To relieve stresses developed from the machining the body may be annealed for a couple of hours at temperatures between 800.degree. C. and 1200.degree. C.

Abstract: It has been found that tri-nickel aluminide compositions are quite sensitive to the ratio of nickel to aluminum in their ability to receive boron as a dopant and that compositions which are relatively poor in the aluminum component can be doped more effectively with boron. Further, it has been found for the nickel aluminides which have lower concentrations of aluminum that the percentage of boron which can be added to the composition to effectively increase the strength of the alloys is favored by the lower aluminum ratio so that higher concentrations of boron are addable. The compositions which result have significant strength properties based on tensile tests of the compositions.

Abstract: A tri-nickel aluminide base composition is provided which has good ductility at all temperatures. The composition has a relatively high concentration of cobalt substituent and is doped by boron. It also has minor concentrations of at least two other substituent metals selected from the group consisting of niobium, hafnium, vanadium, molybdenum and zirconium.

Abstract: Improvements in the strength of atomized and consolidated boron doped tri-nickel aluminides are made possible. The improved strength is achieved by cold rolling and annealing a HIPped aluminide. The improvements are to room temperature properties.

Abstract: A method is taught for rendering a boron-doped tri-nickel aluminide resistant to mechanical failure while at intermediate temperatures of 600.degree. C. to 800.degree. C. due to a hot-short phenomena. The method involves incorporating between 0.05 and 0.30 of cobalt in the composition according to the expression(Ni.sub.1-x-z Co.sub.x Al.sub.z).sub.100-y B.sub.y.The concentration of aluminum, z, is between 0.23 and 0.25 and the concentration of boron, y, is between 0.2 and 1.50 atomic percent. The composition is formed into a melt and the melt is rapidly solidified by atomization and consolidated. The consolidation may be simultaneous with the rapid solidification, as in spray forming, or sequential by atomization to a powder and consolidation of the powder by HIPping. The consolidated body is cold worked to increase the resistance of the body to failure at intermediate temperatures and may be annealed following the cold working.

Abstract: Inhibition of grain size growth in a tri-nickel aluminide is achieved by additions of minor amounts of a metal selected from the group comprising rhenium and molybdenum.

Abstract: A method for achieving both improved high strength and improved ductility in intermediate phases is provided. The method, briefly stated, comprises the steps of providing a melt whose composition substantially corresponds to that of a preselected intermetallic phase having a crystal structure of the L1.sub.2 type, such as nickel aluminide, modified with from about 0.01 to 2.5 atomic percent boron, and rapidly solidifying the melt at a cooling rate of at least about 10.sup.3 .degree. C./second to form a solid body, the principal phase of which is of the L1.sub.2 type crystal structure in either its ordered or disordered state.