Direct Part Marking Specifications for Serialized Batch Traceability Systems
Direct part marking demands precise laser parameter tuning matching substrate chemistry to pass ISO 29158 inspection without structural degradation.
Passivation Resistance
Meaning
Protective oxide film formation on a metal surface or semiconductor layer determines the long-term chemical stability of the material in corrosive environments. This protection, measured as passivation resistance, indicates how effectively the surface barrier resists chemical degradation and dissolution. This property is required for components used in chemical processing plants and cleanrooms.
Oxide Layer
Acid treatments are typically applied to stainless steel parts to strip free iron and promote a chromium-rich surface. The resulting passivation resistance prevents localized pitting and rust formation when the component is exposed to moisture. This treatment must be applied uniformly to be effective.
Corrosion Testing
Electrochemical measurements are used to quantify the protective quality of the surface film. Evaluating the passivation resistance involves measuring the corrosion current and the breakdown potential of the oxide layer. High breakdown potentials indicate a more stable and durable barrier.
Acceptance Specification
Purchase agreements for pharmaceutical piping and bioreactors require certified proof of surface treatment before delivery. A failure to achieve the required passivation resistance under test conditions can lead to product contamination and premature piping failure. Therefore, the supplier must provide test certificates showing that the passivation layer meets the engineering standard.
If the tests fail, the supplier must re-treat the system and cover the delay penalties specified in the master supply agreement.