Citric Acid Passivation Services

Optimize Stainless Steel Before Coating

Maximize Performance of your Products with Citric Passivation before Coating

SilcoTek now offers citric acid passivation as a premium surface preparation step before applying our game-changing coatings. Passivation enhances the surface chemistry and inherent corrosion resistance of stainless steel by removing free iron that causes rouging, rust, and undesirable surface interactions. Semiconductor, biopharmaceutical, medical, and other industries where purity is paramount rely on citric acid passivation on stainless steel and other alloys. 

While passivation is not required before SilcoTek’s coating processes, surface cleanliness is critical to coating success. Passivating metal parts before coating creates an optimal coating surface and increases the corrosion resistance and overall performance of coated parts. SilcoTek offers Citric 2 passivation per ASTM A967 and other customer specifications. Combined with our cleanroom packaging services, SilcoTek is your trusted partner for highly value-added coated products. 

Passivation line

SilcoTek’s citric acid passivation services include: 

  • Citric 2 passivation per ASTM A967 and customer specifications 
  • Sonicated tanks with flow-through capability 
  • Forced air drying 
  • Robust quality assurance and control using copper sulfate test

Citric Passivation Data

ASTM A967 Standards

SilcoTek's ASTM A967 Citric 2 Passivation meets or exceeds SEMI F19 ultra high purity requirements. See chart below for SilcoTek's citric passivation line measured ratios.
Sample Cr/Fe Total CrOx/FeOx Estimated Oxide Thickness (nm)
1 1.9 3.2 2.4



Corrosion Performance

When paired with SilcoTek's Dursan coating technology, citric passivation has shown to improve the lifetime of the surface, reducing the corrosion rate by over half during the first month of exposure. Dursan corrosion passivation data


How Passivation Works

Passivation Graphic