Determination of the Effects of Milling Atmosphere on the Production Process and Characteristics of Boron Nanopowders

The unique properties of boron powders will make an attractive prospect for practical applications in many industrial fields. Therefore, investigation of the effective agents on preparation of this material is very important. In this research, the effect of milling atmosphere on synthesis process of the boron nanopowders and properties of final products was investigated in a planetary ball mill. The process was performed using stoichiometric amounts of B2O3 and Mg powders as reactants (7.3 g). Milling was carried out at room temperature with a ball-to-powder weight ratio (22:1) and with a rotation speed of 520 rpm, in argon and air atmospheres for 9h, separately. Milled powders were leached by hydrochloric acid (25 wt%) and distilled water (twice) and the final products were dried. According to the obtained results, the amount of final product and its purity were more in the argon atmosphere than air. The EDS analyses results showed that boron powder can be prepared with the purity of about 90% in the mentioned conditions in the argon atmosphere. In addition, XRD analysis revealed that the product has a non-crystalline structure. Also, SEM observations confirmed the particle size distribution of between about 48 to 81 nm.