Directionally solidified cobalt-base eutectic alloys

An article of manufacture having improved high temperature properties, improved fiber volume fraction and improved fiber density comprising a unidirectionally solidified anisotropic metallic casting comprising

• a. a matrix of a cobalt-base superalloy consisting essentially of, on a weight basis, 10-20% nickel, 10-20% tungsten, and less than 10% chromium, 10-23% tantalum, 0.1-1.5% carbon and the balance being essentially cobalt;
• and
• b. an aligned eutectic predominantly tantalum monocarbide reinforcing fibrous phase embedded in the matrix.

An article of manufacture having improved high temperature properties, improved fiber volume fraction and improved fiber density comprising a unidirectionally solidified anisotropic metallic casting solidified at a rate greater than 1/4 inch per hour comprising

• a. a matrix of a cobalt-base superalloy consisting essentially of, on a weight basis, 10-20% nickel, 8.1-25% tungsten and less than 10% chromium, 10-23% tantalum, 0.1-1.5% carbon and the balance being essentially cobalt;
• and
• b. an aligned eutectic predominantly tantalum monocarbide reinforcing fibrous phase embedded in the matrix.

A method of improving the high temperature properties, fiber volume fraction and fiber density of a unidirectionally solidified anisotropic metallic casting comprising directionally solidifying at the eutectic solidification temperature of the alloy, at a solidification rate greater than 1/4 of an inch, an alloy matrix comprising a cobalt-base superalloy consisting essentially of, on a weight basis, 10-20% nickel, 8.1-25% tungsten, less than 10% chromium, 10-23% tantalum, 0.1-1.5% carbon and the balance being essentially cobalt, said alloy matrix having an aligned eutectic predominantly tantalum monocarbide reinforcing fibrous phase embedded therein.

A method of improving the high temperature properties, fiber volume fraction and fiber density of a unidirectionally solidified anisotropic metallic casting comprising directionally solidifying at the eutectic solidification temperature of the alloy, at a solidification rate greater than 1/4 of an inch, an alloy matrix comprising a cobalt-base superalloy consisting essentially of, on a weight basis, 10-20% nickel, 10-20% tungsten, 0-5% chromium, 10-23% tantalum, 0.1-1.5% carbon and the balance being essentially cobalt, said alloy matrix having an aligned eutectic predominantly tantalum monocarbide reinforcing fibrous phase embedded therein.