A Detailed Experimental Assessment of Microwave Heating of Titanium Hydride Powder
Powder metallurgy (PM) of titanium hydride (TiH2) has emerged as an attractive alternative to PM of Ti. Microwave (MW) heating has the potential to further facilitate the development of PM TiH2 as TiH2 is essentially a ceramic material. A detailed assessment has been made of the effectiveness of MW heating of Ti-xTiH2 (x =0-100) powder compacts through 30 experiments conducted under a variety of conditions. MW hybrid heating (i.e. when assisted with a SiC MW susceptor) proved to be reliable and consistent in heating Ti-xTiH2 powder compacts and the heating rate increased progressively with increasing TiH2 powder content, indicating that TiH2 powder is more responsive to MW heating than Ti metal powder. However, heating of TiH2 powder compacts by MW radiation without the assistance of a SiC MW susceptor proved to be inconsistent and unpredictable, where successful heating (heated to 1300°C in 20 min) was achieved but many failures also occurred. However, the use of SiC can cause contamination (Si and C). The challenges of heating of TiH2 powder by direct MW radiation were discussed.