EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Boron-doped molybdenum silicides have been already recognized as attractive candidates for space and ground ultra high-temperature applications far beyond limits of state-of-the-art nickel based superalloys. In this work, we are exploring a new method for a fabrication of Mo-Si-B alloys (as coatings or small bulk components) by utilizing a pressure-less reactive melt infiltration approach. The basic assumption of this approach is a synthesis of binary and complex intermetallic phases (silicides, borides, borosilicides), through a direct interaction of Si-B melt with molybdenum.
The main purpose of this work, was to examine the effect of temperature and time of Si-B melt interaction on the structure and morphology of the reactively formed products. For this purpose, sessile drop experiments were carried out on the eutectic Si-3.2B (wt%)/Mo couples at tempearture varying between 1385-1550 C and holding time between 10 to 30 minutes. The solidified sessile drop couples were subjected to structural characterization by means of light microscopy and scanning electron microscopy analyses perfomed at "top-view" and on cross-sectioned interfaces. The effect of apllied processing conditions on structure, morphology and distribution of involved phases, was discussed.