Current Status of Titanium-Boron Composites for Gas Turbines

A process to manufacture titanium-boron composites has been demonstrated with a 30-filament tape in which reaction is controlled to a few hundred Angstroms of boride. This tape has good properties—indicating efficient use of the boron reinforcement—combined with good reproducibility (coefficient of variation of tensile properties approaches 2 percent). Simulated exposures confirm predictions that many thousands of hours of service life are possible at temperatures up to 1200 F. In addition, creep, fatigue, compression, cross tensile, and shear properties are presented. Application of this metal matrix tape to gas turbines is discussed. It is shown that the advantages of boron-reinforced plastic tapes in manufacturing are combined with the advantages of a metal matrix for shear load transfer, cross tensile strength, erosion resistance, and high-temperature performance.