Gradient Nanostructure, Diffusion Mechanisms, and Performance of Fe-Si (6.5 wt.%) Alloy Powders Prepared Using a...

Area of Science:

• Materials Science
• Powder Metallurgy
• Nanotechnology

Background:

• Traditional Fe-Si alloy powder preparation is carbon-intensive.
• High-frequency soft magnetic composites require efficient Fe-Si powder precursors.

Purpose of the Study:

• Develop a green, melt-free Fe-Si alloy powder preparation method.
• Utilize defect-architecture engineering for low-temperature alloying.
• Fabricate high-performance soft magnetic composites.

Main Methods:

• Surface mechanical attrition treatment (SMAT) on iron powders.
• Dual-stage heat treatment: low-temperature Si infiltration (565°C) and homogenization (900°C).
• Defect-gradient nanostructure creation for enhanced diffusion.

Main Results:

• Achieved rapid alloying and uniform silicon distribution at reduced temperatures.
• Fe-Si@boron nitride composites showed low power loss (201.5 kW/m³ at 100 kHz) and high permeability retention (>80% at 7.96 kA/m DC bias).
• Outperformed commercial soft magnetic composite counterparts.

Conclusions:

• Defect-enabled route offers an energy-efficient strategy for low-temperature diffusion alloying.
• Scalable production of high-performance soft magnetic composites is feasible.
• This methodology significantly reduces the carbon footprint of Fe-Si alloy powder production.