Titanium alloy ion implantation is a new process that u […]
Titanium alloy ion implantation is a new process that uses high-energy ion bombardment to change the surface properties. It is like a bullet hitting an object, which can purify the surface of the object, and change the composition and structure of the surface layer of the object, thereby increasing The hardness of the surface improves the abrasion and corrosion resistance of the object. Compared with physical or chemical vapor deposition, the main advantages are: ①The film is well combined with the substrate, and has strong resistance to mechanical and chemical effects without peeling; ②The injection process does not require an increase in the temperature of the substrate, so that the geometric accuracy of the workpiece can be maintained; ③The process is repeated Good sex and so on. Many researchers have reported that nitrogen ion implantation has a good effect on improving the surface composition, microstructure, hardness and tribological properties of Ti6Al4V titanium alloy. TiC is also a super hard phase, so titanium alloy can also strengthen the surface of titanium alloy by ion implantation of carbon. However, since plasma-based ion implantation is not a continuous process, when each negative pulse potential is applied, as the pulse potential drops from zero to a valley, and then rises to zero, two processes, sputtering and implantation, occur. If the plasma contains metal or carbon ions, when the pulse potential is zero, a single carbon deposition layer will be formed on the surface under certain conditions. Under the action of a certain pulse voltage (10~30kV), the structure of the single carbon layer It is diamond-like carbon (DLC). Thus, a surface modified layer with lower friction coefficient and better wear resistance than the nitrogen injection layer can be obtained. The single carbon layer on the surface is experimentally determined to be a DLC film. The surface hardness of the titanium alloy treated in this way is increased by 4 times. When the friction pair is formed by the same material, the friction coefficient is reduced from 0.4 to 0.1 under dry friction conditions, and the wear resistance is increased by more than 30 times compared with the non-ion implantation. .
The equipment to realize the metal ion implantation process is generally composed of three parts: a metal ion source and a high-energy accelerator (to obtain high-speed energy for implanted ions) and a vacuum chamber. With the development of implantation technology, people are interested in improving the performance of titanium alloys and reducing the cost of titanium alloys. Ion implantation technology can be used to change the performance of aerospace, biomedicine, tourist bus parts and cutting tools. The effect of improving the wear resistance of cutting tools is very significant, and the cutting speed is increased by 58%. Under low speed, ion implantation is more than 60% longer than the life of unimplanted tools at low speeds. Generally, nitrogen, carbon or metal ions are implanted. If the implantation depth is increased, the technology will completely replace the plasma sprayed aluminum coating. The implantation technology improves the titanium Wear resistance makes it possible for titanium to be used on fuel injectors and piston rings. In addition, the injection of metal aluminum can significantly improve the corrosion resistance of titanium. The corrosion resistance of titanium injected with molybdenum in HZSO; increases Qiao 00 times. Zinc injection can completely improve the corrosion resistance of Ti-6AI-4V.
The TIN and CrN coatings made by the usual PVD (physical vapor deposition), because the substrate temperature exceeds 400 ℃, and the oxide layer of anatase or rutile structure formed on the titanium surface at this temperature is very high. It is hard to remove, so it is more difficult to achieve an excellent bond between the coating and the substrate. In order to solve this problem, a HyPeinn coating process has emerged. The outstanding feature of this process is that the surface of the substrate is bombarded with high-energy ions before implantation to remove the original substrate such as: 6061 aluminum alloy, Ti-6Al-4V, 440C stainless steel The inherent oxide film makes the coating bond with the fresh substrate surface, and its bonding force is twice that of the usual industrial ion plating, and the residual stress is quite low. TIB: Treating its residual stress with this technology can reduce 3 factors. This technology has no obvious damage to the mechanical properties of the substrate. It can also reduce the deposition temperature.