Influence of Fe Particle Size Distribution on Chemical Homogeneity, Microstructure, and Crack Formation in Fe–SiC Powder Blends Processed by PBF‐LB/M

Powder blending provides a flexible route for alloy design in powder bed fusion of metals using a laser beam (PBF‐LB/M), but differences in particle characteristics can affect melting, chemical homogeneity, and crack formation. Previous work on Fe–SiC powder blends indicated a particle‐size influence, leading to the expectation that finer Fe particles would improve consolidation and homogenization. This study investigates the effect of Fe particle size distribution on processability, microstructure, and chemical homogeneity. Two blends containing 95 wt.% Fe and 5 wt.% SiC were prepared using Fe particle sizes of 20–45 µm (M45) and 20–63 µm (M63), while the SiC fraction remained constant at 20–63 µm. Both blends achieved a relative density of 99.78%. However, M45 exhibited extensive cracking and larger compositional fluctuations, whereas M63 showed a broader crack‐free processing window and slightly improved elemental homogeneity. M45 also exhibited lower but more uniform hardness, while M63 showed higher average hardness with greater local variation. Contrary to the initial hypothesis, the coarser Fe fraction provided more stable processing and improved chemical uniformity, demonstrating that finer Fe particles do not necessarily enhance homogenization or process stability in blended PBF‐LB/M systems.