Heat-Resistant RuAl-Based Alloys: Part Ⅱ. Powder Alloys-Preparation via Reaction Sintering

摘要

Refractory ( T _(m)= 2100°C), heat-resistant ruthenium monoaluminide RuAl, is lighter (ρ = 7.97 g/cm~(3)) than Ni superalloys, is considered a promising candidate material for operation in a high-temperature range and at relatively low loads within high-speed oxidizing gas flows at a temperature higher not only than operating temperature T _(op)but also higher than the melting point T _(m)inherent both in nickel superalloys and in nickel and titanium aluminides. Ruthenium aluminide RuAl is an ideal candidate for potential use in protective coatings too. In the second part of the paper, we have considered the possibilities for obtaining alloys based on RuAl directly from the initial ruthenium and aluminum powders via combining the temperature–time modes of the reaction sintering (RS), as well as the sequence and intensity of pressure application under RS. In this case, no specialized equipment is required for obtaining initial powders with a given composition, and no restrictions are imposed on the particle size distribution in the initial powders.