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TechTalk

TiCN Coating

TiCN or Titanium Carbo-Nitride is a type of thin-film coating made from Titanium Nitride. In many applications, TiCN can have a slightly better friction coefficient than TiN due to its somewhat higher hardness; the primary application of this coating is to obtain enhanced abrasive wear resistance.

Titanium Carbonitride, blue-grey in color, offers improved wear and built-up edge resistance due to its hard, smooth finish. TiCN is well-suited to drilling and reamer applications that generate moderate temperatures at the cuffing edge because of its good adhesion, toughness, and resistance to chipping.

A carbide end mill is excellent for drilling, reaming cast iron, and aluminum alloys with high silicon content, copper, and other abrasive material. In addition, it is suitable for milling materials of chip classes 20 and 40. Since TiCN has such a low oxidation temperature, coolants must be applied correctly at the cutting edge to control the temperature. Failure to do so may cause the coating to wear away prematurely.

An Overview of Common Coating Characteristics

Hardness

The best way to prolong the tool life is to produce a high surface hardness coating. A tool will last longer if the material or surface is more rigid. Compared with Titanium Nitride (TiN), Titanium Carbo-Nitride (TiCN) has a higher surface hardness.

By adding carbon, TiCN gains a 33 percent improvement in hardness range changes roughly from 3,000 Vickers to approximately 4,000 Vickers. In production work involving non-ferrous materials, this coating is favored because of its harder surface and its ability to run at speed two to three times that of uncoated tooling.

The Resistance of Wear

As this name suggests, it refers to a coating's ability to protect against abrasion. However, the material may not be tough, but elements and processes applied during production may affect cutting edges or forming lobes.

Lubricity of the Surface

Friction is increased, more heat is generated. The result is a shorter coating land, which causes the coating to fail. On the other hand, a lower coefficient of friction can significantly increase tool life. It is possible to reduce heat by making a surface with a smooth or irregular surface.

By having a slick surface, chips can rapidly slide off the tool without generating excessive heat. In comparison with non-coated versions, surfaces with a higher surface lubricity can also increase speed. The surface lubricity further prevents the galling of the material.

Temperature of Oxidation

A breakdown occurs here when the treatment is no longer effective. Applications that require high temperatures will perform better with higher oxidation temperatures. In some cases, Titanium Aluminum Nitride (TiAlN) coatings do not have the same hardness as Titanium Carbon at room temperature. Still, they prove to be more effective when heat is generated.

A coating formed between the tool and the cutting chip remains hard at high temperatures due to aluminum oxide that forms between the tool and the chip. This layer allows heat to be transferred into the part or chip from the tool.

Anti-Seizure

A property of this type prevents material from accumulating on the tool because there is reduced chemical reactivity between it and the cutting material. A built-up edge (BUE), typically found on non-ferrous metals such as brass or aluminum, can cause the tool to chip or cause the part to be oversize. A material that begins adhering to a tool continues to attract.

Aluminum deposits grow larger after every hole when it is machined with the forming tap. After a while, the pitch diameter becomes so large that the part is scrapped since it is too large. In the event of improperly designed or insufficiently concentrated coolants, anti-seizure coatings could prove helpful.

TiN (Titanium Nitride)

This oxidation heated PVD (physical vapor deposition) coating makes surfaces harder and increases hardness. An ideal coating for this application is used with cutting and forming tools that have high hardness.

TiCN (Titanium Carbo-Nitride)

It is a type of coating in which carbon is added to increase hardness and improve surface lubricity, and it is ideal for high-speed steel (HSS) cutting tools.

TiAlN or AlTiN (Titanium Aluminum Nitride)

A coating of this type has a formed layer of aluminum oxide, which gives the tool a longer lifespan when exposed to high temperatures. This coating is primarily used for tooling with a carbide that uses little to no coolant. In AlTiN, aluminum and titanium are proportionately present in higher concentrations than in TiAlN. Hence, it is another possible material for high-speed machining (HSM).

If you have any questions about carbide cutting tools, end mills, drills, etc. be sure to reach out to us @ sctools.co/Home or call us at (877)737-0987. We help you machine better!