TiN: The titanium-nitride coatingNovember 15, 2017
Do you wonder if it makes sense to drill with a TiN-coated drill in aluminum? In this article we describe the properties of the TiN coating - and, of course, answer the aluminum question.
General information about TiN coating
The titanium nitride coating (TiN), is the most commonly used standard coating and universally applicable. In machining it is mainly used as wear protection. Compared to uncoated tools, TiN-coated tools offer up to three to four times longer service life. Titanium nitride is a chemical compound of the two elements titanium and nitrogen. The coating thickness is between 1-7 micrometer (μm). Thicker layers tend to crack.
For which applications is TiN coating suitable?
Thanks to its versatility, the TiN coating is a long-established all-round coating type and can be used for a wide range of applications. The coating is very suitable for cutting steel (N/mm²) <900, brass and cast iron. The maximum application temperature is 600° Celcius (approx. 1,100° Fahrenheit), that means that at higher temperatures, the coating is slowly destroyed.
Cooling is recommended.
Can I use TiN in aluminum?
Chemically speaking, titanium has a special affinity for aluminum. During the drilling process, under the influence of pressure and heat, chemical and physical diffusion processes are triggered especially at the cutting edges and in the chip flutes. These processes cause aluminum to bind into the coating, aluminizing the surface of the drill. This leads to an increase of friction between the tool and the material. At the same time, chip removal or chip discharge is so decisively impaired that further work becomes impossible.
For this reason, you have to use cooling and machining aluminum is only possible with stationary machine tools using forced liquid cooling.
- Three to four times longer service life
- Most common standard coating and universally applicable
- Chemical compound of titanium and nitrogen
- Nano hardness: up to 24 Gigapascal (GPa)
- Coat thickness: 1-7 μm
- Coefficient of friction: 0.55 μ
- Temperature: 600°C
- Application: Steel (N/mm²) <900, brass and cast iron
- When machining aluminium only suitable with stationary machine tools using forced liquid cooling
- Cooling is recommended
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