AISI 420 Stainless Steel Foil (Light Tight)

AISI 420 Stainless Steel Foil (Light Tight) is a martensitic chromium alloy engineered for high hardness, excellent wear resistance, and reliable light impermeability, achieved through a defect-free surface that blocks all external light transmission. In foil form, it combines precision dimensional stability with mechanical robustness, making it ideal for industries such as aerospace, precision optics, and medical devices, where both structural integrity and optical shielding are critical. Common uses include precision light-blocking shims in instrumentation, optical enclosure linings, and wear-resistant sealing strips in light-sensitive manufacturing environments. Research explores optimizing its microstructure for improved fatigue strength, surface treatments such as plasma oxy-nitriding to enhance corrosion and hardness, and advanced manufacturing routes like laser powder bed fusion for custom geometries. This combination of optical shielding capability with mechanical reliability makes it a premium choice for high-performance scientific and industrial applications.

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Properties

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Material Properties for Alloys

Mechanical Properties

Element	Value
Elongation at break( % )	>12
Modulus of elasticity( GPa )	200
Tensile strength( MPa )	860

Electrical Properties

Element	Value
Electrical resistivity( µOhmcm )	55
Temperature coefficient( K⁻¹ )	-

Thermal Properties

Element	Value
Melting point( C )	1450
Specific heat( J K⁻¹ kg⁻¹ )	460@23°C
Thermal conductivity( W m⁻¹ K⁻¹ )	24.9@100°C
Coefficient of thermal expansion( x10⁻⁶ K⁻¹ )	10.3@0-100°C