Consolidation of (001)-Oriented Fe–Ga Flakes for 3-D Printing of Magnetostrictive Powder Materials

Abstract

Additive manufacturing (AM) of metallic materials is an emerging technique for the printing of 3-D components using metal powders. The use of thin flakes of magnetostrictive (001)-oriented Fe–Ga powder in a composite matrix for the design of pressure and strain sensors has been demonstrated. This paper extends that work and presents a preliminary evaluation of two methods for the consolidation of magnetostrictive Fe–Ga alloy flakes, using a hot press and arc melting. Flake-shaped powders of Fe80Ga20 and Fe73Ga27 alloys were prepared with varying particle sizes up to $250~\mu \text{m}$ in diameter using a high energy wet ball milling process. The surfaces of the flakes produced were predominantly parallel to the (001) crystallographic plane. Hot pressed Fe–Ga disk samples at 850 °C showed increases of packing density and saturation magnetization with an increase of the particle size because higher thickness to diameter aspect ratios in the flakes facilitated ordering of flakes whereby they more easily defaulted to sitting on one another in layers. We also employed arc melting and binder infiltration techniques to demonstrate the potential suitability of the oriented flake form of this magnetostrictive alloy for AM using 3-D printing methods.