Developed for the aerospace industry as a REACH-compliant replacement for hard chrome plating (HCP) and HVOF.

Hardide-A has been developed specifically to meet the needs of the aerospace industry. It is an environmentally compliant and technically superior replacement for HCP and HVOF coatings, providing enhanced protection against corrosion and chemically aggressive media, wear, galling, fretting and fatigue. Hardide-A matches HCP in thickness and hardness and outperforms the material in several key properties including enhanced protection against corrosion, wear and chemically aggressive media. The transition from hard chrome to Hardide-A is facilitated for customers as no significant changes are necessary in part dimensions or drawings.

Hardide-LA is an ultra-low temperature variant of Hardide-A which is suitable for coating grades of steel and alloys sensitive to the 500°C / 932°F process temperature. It is produced at the significantly reduced temperature of 350°C / 662°F.

– Can be applied to internal and external surfaces and complex shapes uniformly

– Smooth, uniform as-coated surface finish minimises expensive grinding and finishing operations.

– Easily applied to a wide range of metallic substrates including ferrous and nickel-based alloys, and most grades of stainless and carbon steels

– Applications include door pins, bushes, bearings, hooks, catches, landing gear, flap tracks and slats, sleeves, rods, valves, pistons, actuators, compressors, shafts, hydraulic and pneumatic cylinders

Hardide Coatings’ UK and USA manufacturing sites are approved to ISO 9001 and aerospace AS 9100 certification. The UK site is also accredited to Nadcap and ISO 14001.

KEY PROPERTIES

PARAMETER HARDIDE-A
Microhardness [kgf/mm2] 800 – 1200 Hv100
Coating Thickness Typically 50 – 100 microns (0.002 – 0.004”)
Coating Toughness Excellent. Good resistance to impact and thermal shock. High load capability.
Strain to Fracture Higher than 0.3% (3000 microstrain)
Adhesion Tensile Bond Strength Better than 70 MPa or 10,000 psi

Under standard bond test ASTM C633-01, the Hardide coating adhesion bond is proven to be higher than the adhesive ultimate strength of 70 MPa (10,000 psi)

Coating Composition Tungsten with nano-structured Tungsten Carbide

Does not contain Cobalt or other metal binder materials used in Cemented Carbides and thermal spray coatings

Coating Porosity < 0.5% as measured in accordance with ASTM E2109
Appearance Coating as applied is light gray

Finishes to a high metallic lustre when polished

Finishing Operations Grinding, Honing, Lapping, Polishing, Super-finishing
Surface finish As coated 0.4 – 0.6 microns Ra / 16-24 μin

Can be polished to 0.2 – 0.3 microns Ra / 8 – 12 μin

Can be super-finished to 0.02 microns Ra / 0.8 μin

Corrosion Resistance Resistant to acids, H2S and aggressive chemicals

Passed 750 hours neutral salt spray corrosion test ASTM B117

Coating Temperature Typically up to 500°C / 932°F max

Hardide-LA – ultra-low temperature option – 350°C / 662°F max for temperature sensitive substrates

Electrical Resistivity @ 20°C 5.5 microhm-cm
Linear Coefficient of Expansion 4.3 x 10<sup>-6</sup> per ºC
Density @ 20ºC 19.3 (gm/cc)
Thermal Conductivity @ 20ºC 174 W/m·K
Specific Heat Capacity @ 20ºC 0.132 J/g·K