Mechanical Milling Method in Tantalum Hydrides Preparation

Abstract

There are several processes which some tantalum compounds can be prepared, including hydrides. In this work, the synthesis of some phases of tantalum hydrides (Ta-hydrides) is reported using the mechanical alloying technique. This type of hydride was formed "in situ" during mechanical milling process. During this process hydrogenated solvent dissociates into hydrogen atoms that react with tantalum particles. Metallic Ta with a purity of 99.8% was used to obtain their corresponding hydrides. The tantalum hydrogenated phases were synthesized with a spex-type high-energy ball mill. With this system, relatively short times were programmed from 5 to 20 h. In addition to the hydrides, various oxides were obtained during the milling process, which were formed as a function of the milling time. To know the phases formed, characterization techniques such as DRX and SEM were used. Thermogravimetric analysis (TGA) was another technique used for their analysis. With the result of X-ray diffraction, tantalum hydrides (Ta2H and TaH0.5) were identified after 20 h of milling. Some hydrogenated solvents such as methanol can be used as a source of hydrogen to form "in situ" hydrides in this case of tantalum.