|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Powder Metallurgy of Light, Reactive and Other Non-ferrous Metals
||D-53: 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 (ZrB2 and HfB2) are promising for ultra-high temperature applications. Self-propagating high-temperature synthesis (SHS) is attractive for the fabrication of such materials. SHS of ZrB2 and HfB2 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 ZrB2 and HfB2 powders can be densified by pressureless sintering using additives. Here, we report the results of using mechanical activation for improving magnesiothermic SHS of ZrB2 and HfB2 followed by pressureless sintering.
||Planned: Supplemental Proceedings volume