Ni-Co-Cr Base Casting Alloy

摘要

An improved Ni-Co-Cr base casting alloy is particularly useful as a directionally solidified article in the form of a gas turbine blade tip portion to provide resistance to the combination of oxidation, sulfidation and thermal fatigue at elevated temperatures. The alloy base is enhanced through the alloying additions of Ta, Al, W, C, Si and optionally La. The composition range in weight percent consists of: Nickel 32-34 Cobalt 32-34 Chromium 22-24 Tantalum 2.5-3.5 Aluminium 3.5-4.5 Tungsten 2.5-3.5 Carbon 0.4-0.5 Silicon 0.6-0.9 Lanthanum 0-0.1