Niobium-silicide based composites resistant to high temperature oxidation

摘要

A niobium-silicide refractory metal intermetallic composite adapted for use in a turbine component comprises: between about 19 atomic percent and about 24 atomic percent titanium; between about 1 atomic percent and about 5 atomic percent hafnium; up to about 7 atomic percent tantalum; between about 16 atomic percent and about 22 atomic percent silicon; up to about 6 atomic percent germanium; up to about 5 atomic percent boron; between about 7 atomic percent and about 14 atomic percent chromium; up to about 4 atomic percent iron; up to about 4 atomic percent aluminum; up to about 3 atomic percent tin; up to about 3 atomic percent tungsten; up to about 3 atomic percent molybdenum; and a balance of niobium. A ratio of the sum of atomic percentages of niobium and tantalum present in said niobium silicide refractory intermetallic composite to the sum of atomic percentages of titanium and of hafnium present in said niobium silicide refractory intermetallic composite has a value between about 1.4 and about 2.2. Chromium and iron together comprise between about 7 atomic percent and about 15 atomic percent of the niobium silicide refractory intermetallic composite, and silicon, germanium, and boron together comprise between about 16 atomic percent and about 22 atomic percent of the niobium silicide refractory intermetallic composite.