Common blade coatings; their uses, advantages, and disadvantages.
Blade coatings are useful in many industrial applications all over the world. Changing the material properties of the blade body without sacrificing the steels inherent strengths or stainless steels ability to resist corrosion. Some of the most common desires or applications of coatings to blade surfaces are to prevent adhesive buildup or extend life. York Saw and Knife understands and frequently applies coatings to our end products to meet or exceed our customer requirements. Over the years we’ve built up a large knowledgebase and common problem/solution circumstances for coatings.
Teflon black nonstick coating
Similar to the nonstick coating on frying pans, this coating is engineered to be more durable than what’s found on consumer products. Typically used in industry to prevent sticky buildup from food, plastics and adhesives. There are many formulations of this type of coating each with a unique strength, such as wear resistance, exceptional release properties, corrosion resistance, ect. But the only FDA approved coating has a high curing temperature that can affect the heat treating of an industrial knife. In this case it is usually substituted for another type of coating. Something to keep in mind this coating is applied with a .001” – .004” thickness and can dull sharpened edges and change machine fit.
Titanium Nitride Coating
This coating commonly referred to as TiN coating. This is an incredibly hard ceramic powder and is often used as a coating on titanium alloys, steel, carbide and aluminum parts to enhance the surface properties of the substrate.
Applied as a PVD or Physical Vapor Deposition, TiN is used for the hardening and protection of cutting and sliding surfaces), and for surgical devices as non-toxic coating. A coating of under 5 micrometers (0.00020 in) is used in most applications. Industrial Knives are applied with the coating to decrease the friction of the blade surface and strengthen the cutting edge against premature wear.
TiCN – Titanium Carbon Nitride
This coating is used in the same applications as TiN coating but performs better in certain applications with it’s higher surface hardness and is commonly chosen when cutting harder materials or forming applications. This coating, overall, provides higher tool life and productivity.
Electroless Nickel Plating
Unlike electroplating, electroless plating processes generally do not require the passage of electrical current through the bath and substrate; the reduction of metal cations in metallic solution is achieved through an autocatalytic reaction by purely chemical means. Thus, electroless plating produces an even metal layer regardless of the surface structure – as opposed to electroplating, which suffers from uneven current density due to the influence of the subtract form on the bath’s electrical resistance and hence on the current distribution within it. It may also be applied to non-conductive surfaces.
Electroless plating has many industrial applications, from mere decorative to corrosion prevention and wear prevention. Composite coatings can be applied by suspending appropriate powders in the bath.
For Industrial Blades and knives this coating is usually chosen for its surface smoothness and to keep materials from building up. Not for it’s surface hardness.
Hard chrome plating is, in fact, one of the most effective and commonly used finishing processes in the industry. Such plating is usually used for that purpose to help resist abrasion and corrosion. Moreover, industrial hard chrome also helps to boost the wear of a product.
The application of hard chromium offers mild protection against corrosion and oxidation of the coated steel. For industrial blades this coating is chosen to protect the blade from oxidation while still retaining surface hardness.