Anisotropic Magnets Fabricated by Cold Spray Additive Manufacturing

Abstract

The development of additive manufacturing (AM) of permanent magnets is rapidly growing due to the competitive advantages they offer. AM of complex shape magnets could revolutionize the design of electrical machines potentially allowing for higher performance. Unfortunately, magnetic performance of AM permanent magnets is often limited due to the use of isotropic powders. In this study, Al-NdFeB composite permanent magnets were fabricated by cold spray AM using anisotropic NdFeB powders. Anisotropic powder can improve magnets’ remanence and energy product via particle alignment and subsequent magnetic anisotropy. The effect of gas temperature on deposition rate and magnet performance was evaluated. Magnetic measurements were performed along three orthogonal directions to quantify the level of anisotropy. It is demonstrated that anisotropic powders partially align itself during the cold spray process in the absence of external magnetic field. This could pave the way for a simple and efficient way of fabricating anisotropic magnets.