Synthesis of TiFe Compound from Ball Milled TiH_2 and Fe Powders Mixtures

摘要

TiFe compound was produced by high-energy ball milling of TiH_2 and Fe powders, followed by heating under vacuum. TiH_2 was used instead of Ti in order to avoid the strong particles adhesion to grinding balls and vial walls. Mixtures of TiH_2 and Fe powders were dry-milled in a planetary mill for times ranging from 5 to 40 hours. The amount of sample, number and diameter of the balls were kept constant in all experiments. After milling, samples were heated under dynamic high-vacuum for the synthesis reaction. As-milled and heat-treated materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analysis (DTA). The mean crystallite sizes and microstrains were determined by XRD line profile analysis using the Warren-Averbach method. As-milled materials presented only Fe and TiH_2 phases. Nanostructured TiFe compound was formed after heat treatment. TiH_2 was effective for providing low adherence of the powders during milling.