|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Powder Metallurgy of Light, Reactive and Other Non-ferrous Metals
||Magnesiothermic MASHS and Pressureless Sintering of Diborides of Zirconium and Hafnium
||Sergio Cordova, Evgeny Shafirovich
|On-Site Speaker (Planned)
Materials based on diborides of zirconium and hafnium (ZrB<SUB>2</SUB> and HfB<SUB>2</SUB>) are promising for ultra-high temperature applications. Self-propagating high-temperature synthesis (SHS) is attractive for the fabrication of such materials. SHS of ZrB<SUB>2</SUB> and HfB<SUB>2</SUB> from elements is well known, but it is not suitable for large-scale fabrication because of high costs of raw materials. Magnesiothermic SHS involves reduction of their oxides by magnesium and it is more economically viable. However, the reacting mixtures are low-exothermic and are difficult to ignite. One promising approach to enabling combustion of low-exothermic mixtures is mechanical activation-assisted SHS, which involves a short-duration, high-energy milling step before the combustion process. The obtained ZrB<SUB>2</SUB> and HfB<SUB>2</SUB> powders can be densified by pressureless sintering using additives. Here, we report the results of using mechanical activation for improving magnesiothermic SHS of ZrB<SUB>2</SUB> and HfB<SUB>2</SUB> followed by pressureless sintering.
||Planned: Supplemental Proceedings volume