Chemical Resistance

Chemical resistance refers to a material’s ability to withstand exposure to corrosive substances without degrading or losing function. This property depends on several key factors:

• Material Composition: Alloys, polymers, and composites vary in resistance based on their chemical makeup. For example, stainless steel resists oxidation due to its chromium content, while high-performance plastics resist solvents through stable resin structures.
• Surface Coatings: Protective layers like Armoloy Thin Dense Chrome (TDC), ceramics, or epoxy coatings form a barrier that shields the base material from corrosive media.
• Polymer Cross-Linking: Highly cross-linked thermosets and elastomers offer excellent chemical resistance by maintaining molecular stability under chemical stress.
• Barrier Properties: Low-porosity surfaces slow chemical diffusion. TDC, for instance, provides exceptional inertness for harsh industrial and food processing environments.

Chemical resistance is critical in applications like medical devices, semiconductors, marine components, and chemical manufacturing — where exposure to aggressive substances can otherwise shorten component lifespan.

Chemical resistance is assessed using standardized methods that simulate real-world exposure to aggressive substances. These tests measure how a material changes in weight, appearance, strength, or dimensional stability after chemical contact.

Common Testing Methods:

• Immersion Testing: Samples are submerged in chemicals for a defined time. Engineers track changes in mass, hardness, tensile strength, or surface quality.
• Vapor & Splash Exposure: Materials are placed in environments with chemical vapors or intermittent contact to evaluate surface degradation.
• Flow-Through or Dynamic Testing: Designed for components exposed to circulating fluids, this method measures durability under flow and pressure conditions.
• Standardized Testing Protocols: Common test standards include ASTM D543 (plastics), ASTM G31 (metal corrosion in immersion), and ISO 1817 (elastomers in fluids).

These tests help determine material compatibility, validate protective finishes, and ensure long-term performance in demanding applications like medical equipment, semiconductor tools, and chemical processing systems.

Good chemical resistance refers to a material’s ability to withstand long-term exposure to corrosive substances without significant physical or chemical breakdown. Materials with strong chemical resistance maintain their performance and integrity even in harsh environments.

• High Durability: The material remains stable and unreactive when exposed to acids, bases, solvents, or cleaning agents.
• Minimal Swelling or Deformation: It resists absorption and dimensional changes that could affect fit or function.
• Mechanical Property Retention: The material holds its strength, elasticity, or rigidity after prolonged exposure to chemicals.
• Low Permeability: It acts as a barrier, preventing chemical penetration that could damage internal components or substrates.

Examples of chemically resistant materials include high-grade stainless steels, fluoropolymers like PTFE, and engineered coatings such as Thin Dense Chrome (TDC). These are widely used in industries requiring protection against aggressive substances, including chemical processing, pharmaceuticals, and food production.