Tungsten carbide rotary files are crucial tools in precision machining, renowned for their high hardness, strength, and excellent wear resistance. They play an irreplaceable role in various fields such as mold manufacturing, aerospace, and the automotive industry. To further enhance their performance, extend their service life, and maintain superior performance under specific processing conditions, surface coating technology is commonly applied to tungsten carbide rotary files. This article will provide a detailed introduction to several common surface coatings on tungsten carbide rotary files, with a particular focus on the increasingly popular DLC (Diamond-Like Carbon) coating.

I. Importance of Surface Coatings on Tungsten Carbide Rotary Files

During use, tungsten carbide rotary files come into direct contact with the workpiece and endure significant cutting forces and friction. Therefore, their surface properties directly impact machining efficiency, tool life, and machining quality. Surface coating technology can significantly enhance the wear resistance, oxidation resistance, lubricity, and thermal stability of the tools without altering the properties of the base material, thus meeting a broader range of machining requirements.

II. Common Surface Coatings on Tungsten Carbide Rotary Files

1. TiN (Titanium Nitride) Coating
TiN coating is widely favored for its golden appearance and excellent wear resistance. It can maintain stable chemical properties at high temperatures, reducing friction and wear during the cutting process, increasing cutting speeds, and improving machining accuracy. Additionally, TiN coating provides a certain degree of lubricity, helping to reduce cutting forces and extend tool life.

2. TiC (Titanium Carbide) Coating
TiC coating is renowned for its extremely high hardness and wear resistance. It can maintain the sharpness of the tool under extreme cutting conditions, reducing chipping and wear. TiC coating is often used as an underlayer to enhance the adhesion strength between the coating and the substrate and provide a better base for subsequent coatings.

3. Al₂O₃ (Aluminum Oxide) Coating
Aluminum oxide coating is highly regarded for its excellent high-temperature resistance, corrosion resistance, and chemical stability. It can maintain the integrity and stability of the coating during high-temperature cutting processes, effectively resisting oxidation and corrosion, and is particularly suitable for machining heat-resistant alloys and composite materials.

4. DLC (Diamond-Like Carbon) Coating
DLC coating is a high-performance coating material that has emerged in recent years, featuring extremely high hardness (close to natural diamond), very low friction coefficient, and excellent wear resistance. It can maintain stable performance under high temperatures, high pressures, and high-speed cutting conditions, significantly reducing cutting forces and temperatures, minimizing tool wear and workpiece thermal deformation. DLC coating is particularly suitable for precision machining, high-speed cutting, and dry cutting in high-end machining fields.

III. Advantages of DLC Coating in Tungsten Carbide Rotary Files

1. Ultra-High Hardness
The hardness of DLC coating is close to that of natural diamond, significantly enhancing the cutting ability and wear resistance of tungsten carbide rotary files, extending tool life.

2. Low Friction Coefficient
DLC coating has an extremely low friction coefficient, reducing friction and heat generation during cutting, lowering cutting forces and temperatures, and improving machining efficiency and quality.

3. Excellent Wear Resistance
DLC coating maintains stable performance under high-speed, high-temperature, and high-pressure cutting conditions, effectively resisting wear and chipping, ensuring long-term stability of the tool.

4. Wide Applicability
DLC coating is suitable for processing various materials, including high-hardness alloys, stainless steel, titanium alloys, and other difficult-to-machine materials, as well as ceramics, glass, and other non-metallic materials.

Surface coating technology for tungsten carbide rotary files is an indispensable technology in modern industry. By selecting appropriate coating materials and technical parameters, the performance and service life of tools can be significantly enhanced, meeting various complex machining needs. As one of the best options, DLC coating demonstrates extensive application prospects in high-end machining fields due to its unique performance advantages. With the continuous development and improvement of coating technology, it is anticipated that more high-performance coating materials will be applied to tungsten carbide rotary files in the future, driving the continuous progress and innovation of machining technology.