Anodizing hardcoating

Relative Costs. Chromic anodize costs more than H2SO4 but less than hardcoat anodize. 

Advantages and Uses. Hardcoat anodize, because of its variety of desirable properties, has found widespread use in manufactured products. First, because of it extreme hardness, it is used in situations in which wear resistance is required. Applications include valve/piston assemblies, drive belt pulleys, tool holders and fixtures, and many other items requiring wear resistance. 

Suitable Alloys. Although almost all alloys can be coated, the 6000-series aluminum alloys produce the best bardcoat properties. As with the other anodize types, high-silicon die castings produce the lowest-quality coatings. Also, because the hardcoat process is sensitive to copper, alloys in the 2000 series should be avoided if possible. Alloys containing copper can be bardcoated, but only a relatively few commercial sources have the ability to coat these alloys with reliability. 

Relative Costs. Hardcoat anodize is the most expensive type of anodize. It is generally twice the cost of H2SO4 anodize and 50% more than C1O3 anodize. 

Hardcoat anodizing. As the name implies, a hardcoat finish is tough and durable and is used where abrasion and corrosion resistance, as well as surface hardness, are critical factors. Essentially, hardcoating is a sulfuric acid anodizing process, with the electrolyte concentration, temperature, and electric current parameters altered to... 

---