Optimization of Mechanical Alloying Parameters for Fe-Si-Al Alloy Synthesis: Effects of Vial Volume and Milling Speed on Phase Formation

Abstract

The Sendust alloy (Fe85Si9.6Al5.4) was prepared by mechanical alloying, and the effects of milling time, speed, and the empty volume of the milling vial on its phase formation were investigated. Stoichiometric ratios of the raw materials, silicon, aluminum, and iron, were milled in stainless steel vials with volumes of 300 and 140 mL at different times and with different empty spaces, using a planetary high-energy ball mill. Additionally, the effect of milling speed on the phase formation of Sendust was examined, using a smaller vial. Phase identification was carried out using powder X-ray diffraction (XRD). According to the results, at 350 rpm, the desired phase was obtained in minimum times of 10 and 20 h in the 300 and 140 mL vials, respectively. The desired alloy was formed in 10 h milling at 450 rpm in the smaller vial. Thus, empty space in a vial and milling time are strongly interdependent, so, as empty space decreases, a longer milling time is required. However, at higher milling speeds, minimum required times are reduced in smaller empty spaces. © The Minerals, Metals & Materials Society 2025.