Enhanced Fracture Toughness and High-Temperature Strength of Directionally Solidified Mo-XC Alloys

Abstract

The present article focuses on refractory metals strengthened by ceramic phases to improve the mechanical properties at ambient temperatures as well as at high temperatures. In this work, near-eutectic, directionally solidified (DS) Mo-34TiC and Mo-27ZrC alloys are investigated with regard to their microstructures, fracture toughness at room temperature and compressive strength at high temperatures. Superior fracture toughness as well as competitive strength compared with other Mo-XC composites are achieved. Compressive tests up to 1000 °C on longitudinal and transversal specimens show the significant impact of the anisotropy on the strength.

Efficient Sintering of Mo Matrix Composites—A Study of Temperature Dependences and the Use of the Sinter Additive Ni

“…It is known that the fracture toughness increases with an increase in the volume fraction of moss. An increase in fracture toughness can be achieved if moss forms a continuous matrix rather than individual particles [6,15,16]. The oxidation resistance, on the other hand, increases with a decrease in the volume fraction of moss and the distribution of moss in the form of isolated particles instead of a continuous matrix.…”