Mechanically activated combustion synthesis of molybdenum borosilicides for ultrahigh-temperature structural applications

JOURNAL OF ALLOYS AND COMPOUNDS

卷:670

Article

Esparza, Alan A.¹  Shafirovich, Evgeny¹ 

[1] Univ Texas El Paso, Dept Mech Engn, El Paso, TX 79968 USA

关键词: Intermetallics;    Combustion synthesis;    SHS;    Mechanical activation;    Oxidation;   

DOI  :  10.1016/j.jallcom.2016.02.029

来源: Elsevier

【 摘 要 】

The thermal efficiency of gas-turbine power plants could be dramatically increased by the development of new structural materials based on molybdenum silicides and borosilicides, which can operate at temperatures higher than 1300 degrees C with no need for cooling. A major challenge, however, is to simultaneously achieve high oxidation resistance and acceptable mechanical properties at high temperatures. Materials based on Mo5SiB2 (called T-2) phase are promising materials that offer favorable combinations of high temperature mechanical properties and oxidation resistance. In the present paper, T-2 phase based materials have been obtained using mechanically activated self-propagating high-temperature synthesis (MASHS). Upon ignition, Mo/Si/B/Ti mixtures exhibited a self-sustained propagation of a spinning combustion wave, but the products were porous, contained undesired secondary phases, and had low oxidation resistance. The chemical oven technique has been successfully employed to fabricate denser and stronger Mo5SiB2-TiC, Mo5SiB2-TiB2, and Mo-Mo5SiB2-Mo3Si materials. Among them, Mo5SiB2-TiB2 material exhibits the best oxidation resistance at temperatures up to 1500 degrees C. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

Free