The Influence of Preparation Parameters on the Morphology and Magnetic Properties of Fe-N Powders Obtained by the Gas Atomization Method

Abstract

α″-Fe16N2 materials are of increasing interest for their applications in products such as rare earth-free permanent magnets. The lack of a method of mass production for powders as raw materials delays the preparation of such magnets. Through employing the gas atomization method, we managed to prepare α″-Fe16N2 powders whose morphology and magnetic properties were tailored by the preparation parameters. As a result of optimizing the preparation parameters (ejection temperature and pressure, ejection nozzle diameter, and atomization pressure), we managed to prepare powders with a size of about 30 μm and a content of 31% α″-Fe16N2 phase. The value of the saturation magnetization (234.8 emu/g), the reasonable coercivity value (970 Oe) presented by the prepared powders, and the opportunity of scaling up approaches based on the preparation of powders via gas atomization support the feasibility of preparing α″-Fe16N2 powders at an industrial level.

Innovative Method for the Mass Preparation of α″-Fe16N2 Powders via Gas Atomization

“…Magnetic measurements were performed using a vibrating sample magnetometer (VSM) (Lake Shore VSM 7410, Westerville, OH, USA) in a maximum applied field of 20 kOe, at room temperature. The design and operation of the gas atomization facility is described in detail in our previous work [32]. However, for an easy understanding of the atomization process with the homemade equipment used for the preparation of powders, we will reproduce here the gas atomization sketch (Figure 1) as well as some particular characteristics of the configuration we used in the present work.…”