A brittle metal long regarded as difficult to shape could be moving toward a new manufacturing future. Researchers are investigating whether iron containing 6.5 percent silicon, known as Fe-6.5Si, can be transformed into advanced laminated structures using cold spray technology—a solid-state process that builds materials without melting them. The work, reported in npj Advanced Manufacturing, explores how this combination could help produce magnetic components with high electrical resistance, reduced energy losses and tailored mechanical performance.
Fe-6.5Si is not an ordinary steel. The addition of silicon dramatically increases the electrical resistivity of iron, limiting the circulation of eddy currents that waste energy when magnetic materials operate under alternating fields. That property makes high-silicon electrical steel attractive for electric motors, generators, transformers and emerging power-electronics systems. Yet the same silicon that improves magnetic efficiency also makes the alloy unusually hard and brittle, creating serious problems during conventional rolling, machining and forming. The material can crack before it reaches the complex shapes demanded by modern devices.
Cold spray offers a radically different route. Instead of melting metal powder with a laser, electric arc or furnace, the process accelerates fine particles through a high-speed gas stream toward a surface. When the particles strike at sufficient velocity, they undergo intense plastic deformation and bond to the substrate. The material remains largely solid throughout deposition, reducing the risk of oxidation, solidification defects, grain coarsening and unwanted phase transformations. For Fe-6.5Si, avoiding the thermal cycle of melting could be especially important because the alloy’s brittleness makes conventional fusion-based manufacturing difficult.
The new study, led by H. Das, J.D.E. Atehortua and A. Nittala, examines the potential of Fe-6.5Si cold-spray laminates—structures made by joining or building multiple material layers into a single engineered body. In such laminates, each layer can contribute to the final performance, allowing researchers to control thickness, orientation, interfaces and possibly the combination of magnetic and mechanical properties. Rather than treating the alloy as a material that must simply be shaped, the approach treats it as a platform whose internal architecture can be designed.
The central scientific challenge lies at the interfaces between sprayed particles and between successive deposited layers. During impact, particles must deform enough to break through surface oxides and create intimate metallic contact. If bonding is incomplete, microscopic pores or weak boundaries can remain hidden inside the laminate. These defects may reduce strength, increase magnetic losses or become pathways for cracking. The researchers’ work therefore focuses attention on how processing conditions—including particle velocity, gas pressure, substrate temperature and deposition strategy—govern the final structure.
The absence of melting brings major advantages, but it does not eliminate complexity. High-speed impacts generate severe local deformation, residual stresses and changes in the material’s microstructure. The resulting laminate may contain elongated or heavily distorted grains, interfaces with different levels of bonding and directional properties created by the layer-by-layer process. Understanding these features is essential because magnetic performance depends not only on chemical composition, but also on grain size, crystallographic texture, defects and the ease with which magnetic domains can move through the material.
If the technology can deliver dense, well-bonded Fe-6.5Si structures, its implications could extend far beyond laboratory samples. Electrical machines are under pressure to become smaller, lighter and more efficient as electrification expands across transportation, industry and renewable-energy systems. Magnetic cores fabricated through cold spray could eventually be repaired, locally reinforced or produced in geometries that are difficult to achieve with traditional sheet processing. The ability to deposit material directly onto existing components could also reduce waste and open possibilities for restoring high-value parts rather than replacing them.
The research arrives as manufacturers search for alternatives to energy-intensive and geometrically restrictive production methods. Conventional electrical steels are commonly processed as thin laminations to suppress eddy currents, then stacked and assembled into magnetic cores. Cold-spray manufacturing could offer a complementary strategy by creating layered architectures directly, potentially integrating structural support with magnetic functionality. However, the route to industrial adoption will depend on careful control of porosity, interlayer bonding, dimensional accuracy, surface finish, magnetic hysteresis and high-frequency losses. Long-term durability under thermal and electromagnetic cycling will be equally important.
The significance of the Fe-6.5Si laminate concept is therefore not simply that it provides another way to deposit a difficult alloy. It represents a broader shift toward manufacturing materials through controlled impact and architecture rather than melting and reshaping alone. By combining the electrical advantages of high-silicon iron with the low-thermal-input nature of cold spray, the work points toward magnetic components designed from the inside out. As electrification accelerates, technologies capable of making efficient materials easier to manufacture could become one of the quiet breakthroughs powering the next generation of machines.
Subject of Research: Fe-6.5Si cold spray laminates and their potential for advanced magnetic and structural manufacturing applications.
Article Title: Unraveling the potential of Fe-6.5Si Cold Spray laminates
Article References: Das, H., Atehortua, J.D.E., Nittala, A. et al. Unraveling the potential of Fe-6.5Si Cold Spray laminates. npj Adv. Manuf. (2026). https://doi.org/10.1038/s44334-026-00091-y
Image Credits: AI Generated
DOI: 10.1038/s44334-026-00091-y
Keywords: Fe-6.5Si, cold spray, laminates, additive manufacturing, electrical steel, magnetic materials, solid-state deposition, electric motors, energy efficiency
