Hardide coatings is a family of low temperature CVD (chemical vapour deposition) tungsten carbide based coatings that increase the life of critical metal parts operating in abrasive, erosive, corrosive and chemically aggressive environments.
The coatings have a unique combination of abrasion, erosion and chemical resistant properties while being tough, ductile and impact resistant.
They are applied by low temperature CVD which enables a more flexible coating which can coat internal surfaces and complex shapes. Hardide coatings have many comparable advantages over other hard facing coating technologies:
- Exceptional toughness, flexibility and impact resistant
- Coats internal surfaces and complex shapes uniformly
- Withstands deformations and shock loads
- High hardness
- Chemically resistant
- Very low porosity
- Smooth finish
- Machinability and facilitated finishing
For most applications, a combination of these properties is required. For example, ball valves require a uniform coating of a complex shape, hardness, wear resistance, zero porosity, a smooth finish and often chemical resistance.
There are a number of other hard coatings that have traditionally been used to protect against wear such as hard chrome plating and HVOF spray. Traditional PVD (physical vapour deposition) and CVD coatings help to reduce friction particularly in vacuum applications, and boron diffusion reduces galling. However, each has its limitations and most cannot coat internal surfaces or protect against aggressive media.