1. Preparation method of Titanium Nitride (TiN) films
As early as the 1960s, the research of TiN thin films has begun. However, but the research work turned to a low tide due to the difficulties in the materials and devices. Afterwards, with the improvement of the preparation technology of thin films, the research of TiN thin films started to flourish and the preparation methods are diversified. At present, a great progress has been made.
Physical Vapor Deposition (PVD)
Electron Beam Evaporation Method
At present, the most commonly used vacuum coating method is electron beam evaporation. It is a method that using electron beam to hit the surface of the evaporated material to transfer the energy and then melt and evaporate the material. Electron beam evaporation has the characteristics of large energy density, high thermal efficiency, low heat conduction and heat radiation loss, etc, which can reduce the reaction between the container material and the plating material. Also, the purity of TiN coating can be greatly improved.
Sputter Coating Method
There are two main methods of Magnetron sputtering of TiN film: DC magnetron sputtering and RF magnetron sputtering (using ceramic TiN targets). Recently, the non-equilibrium magnetron sputtering and reactive sputtering are brought forward. Among them, the reactive sputtering method is most used in the preparation of TiN films because of its unique advantages. The magnetron sputtering method of TiN films has the advantages of high sputtering rate, low temperature rise of the substrate, good bonding force of film and substrate, stable device performance, convenient operation and control, etc. At the same time, it also has some shortcomings. For example, the deposition rate is relatively low, the efficiency is poor, which is unfavorable for reducing the deposition cost. Therefore, the magnetron sputtering method is only applied to fields that require high-quality TiN coatings such as optics and microelectronics.
Arc Ion Plating
Since the 1980s, ion plating TiN coating has developed into a high-tech all over the world, the main application is the preparation of wear-resistant coating on high-speed steel and carbide tools, and the gold-imitative decorative coating stainless steel products. Ion plating technology has made great stride in the 90s of the 20th century, recently, the most widely used ion plating method id arc ion plating technology (also known as multi-arc ion plating), it has replaced all other types of ion plating and became the only production process titanium nitride coating industry. During the arc ion plating process, the factors affecting the structure and performance of the coating are arc current, substrate negative bias, substrate temperature, partial pressure of nitrogen, cavity pressure and so on.
2. Application Research Of TiN Coating
TiN film can reduce the material adhesion on cutting edge, improve cutting force, improve the surface quality of the workpiece, and double increase the service life and durability of the cutting tool. Therefore, TiN film is widely used in low speed cutting tools, high speed steel cutting, wood cutting tools and drills. In addition, TiN is also an ideal wear-resistant coating for wear parts, its low adhere tendency help extend the application in many wear systems such as piston packing seals of automotive engines, various kind of bearings and gears, etc. In addition, TiN coating is also widely used in molding tools, such as sheet metal forming tools in automotive.
TiN film is non-toxic coatings with light weight, high strength and excellent biocompatibility. Therefore, it is a very ideal medical metal material and it can be used as implants and surgical instruments implanted in human body. In addition, TiN films can be used as a reinforcing film of other film that has good biocompatible.
TiN film can be coated on the IF-MS2 to improve the wear resistance of MoS2 lubricant. TIN film has the advantages of high hardness, high melting point, high wear resistance, excellent chemical stability, etc, so it can be used on the IF-MS2 to improve the lubricating performance of aircraft and spacecraft engines and other parts. At the same time, it can also to ensure the high temperature and friction performance of aerospace components.
Application Field of Solar Energy
The study of TiN films for stable solar absorption layer in high temperature atmospheric began in 1984, and recently (Ti, Al) N coatings is recommended to apply for solar selective absorbing layers and solar control windows, which is mainly due to high temperature resistance of (Ti, AI) N coating. For application of TiN and TiAlN coatings in Solar Energy, it is still under trial and exploration.