Wholesale Carbonyl Iron Powder Suppliers & Factory

Carbonyl Iron Powder (CIP) is manufactured through chemical vapor deposition—specifically, the thermal decomposition of iron pentacarbonyl [Fe(CO)₅]. This process occurs atom-by-atom in the gas phase, forming perfectly spherical micro-particles with a characteristic onion-skin crystalline structure. In contrast, water or gas atomization produces irregular or semi-spherical particles of larger diameter (typically 20–150 μm), while electrolytic methods produce brittle, sponge-like flakes. The sub-micron fineness (1–8 μm), spherical geometry, and internal domain arrangement of CIP give it significantly higher magnetic permeability, lower high-frequency eddy current losses, and superior sintering kinetics during metal injection molding (MIM).

Raw decomposed carbonyl iron contains approximately 0.7% to 0.9% interstitial carbon and trace nitrogen, imparting high hardness (often called "hard grade"). For metal injection molding (MIM) structural components that require secondary machining or high ductility, the powder undergoes a secondary hydrogen reduction treatment at elevated temperatures. This reduction process decreases carbon content to ≤0.05% and eliminates oxygen/nitrogen, lowering hardness from HV >800 to HV ~150. Reduced CIP facilitates binder wetting, improves green part density, accelerates sintering diffusion, and achieves sintered densities exceeding 7.70 g/cm³ (approaching 98% theoretical density) under standard sintering temperatures (1150°C–1280°C).

Eddy current loss ($P_e$) is proportional to the square of the operating frequency and the square of the particle dimension ($P_e \propto f^2 \cdot d^2 / \rho$). When carbonyl iron particles are coated with a dielectric phosphate, silica, or organosilane nanolayer (thickness 10–50 nm), the inter-particle electrical resistivity ($\rho$) increases dramatically. This nanoscale dielectric barrier confines micro-currents inside individual micron-scale spheres, eliminating bulk circulating currents across the magnetic core. As a result, components maintain low core loss and exceptionally stable inductance values into high frequency bands (100 kHz up to 50 MHz).

Because carbonyl iron powders feature a high specific surface area (0.5 to 2.5 m²/g), exposure to humid ambient air can cause surface oxidation and moisture adsorption. We pack our powder in heavy-gauge steel drums hermetically sealed with double-layer aluminum foil/polyethylene liners, purged with high-purity argon. When stored in a cool (15–25°C), dry (≤50% RH) environment with original uncompromised seals, the certified shelf life is 24 months. If a drum is partially used, the remaining headspace must be purged with dry nitrogen or argon before resealing.

Yes. Through integrated multi-stage air classifiers and variable-energy jet milling, we produce custom-engineered particle size distributions with tight D10, D50, and D90 parameters, as well as bimodal size combinations. For radar absorption materials (RAM), we offer narrow sub-micron cuts (D50: 1.5 – 2.5 μm) that match specific resonance frequency requirements. For diamond tools, we supply tailored cobalt-free or reduced-cobalt pre-alloy blends with specific matrix retention properties.