This paper mainly studies the fluctuation range and influence of (TiZr) N hard film deposition process. The effects of process parameters such as cathode target current and N2 gas flow rate on the microstructure and properties of the film are investigated in it. Studies have shown that fluctuations of deposition process parameters do not have a significant effect on the microstructure and mechanical properties of the film. So the deposition process parameters of (TiZr) N hard film have a large fluctuation range, and the deposition process window has good applicability.
(TiZr) N hard film is a kind of hard reactive film that is superior to TiN in terms of hardness, red hardness and other properties. It has attracted extensive research interests at home and abroad in recent years. These studies mainly focus on Ti/Zr ratios, production methods, organizational structures and so on. However, there are few studies on the adaptability of the deposition process, and (TiZr) N hard film has not been widely applied. As a kind of hard film, the adaptability of its deposition process, or the deposition process window, has practical significance that cannot be ignored in the application of coating tools and coating dies. Therefore, in this paper, process adaptability of two (TiZr) N hard films with a large difference in distribution ratio is studied in order to determine the suitability of (TiZr) N hard film deposition process.
Test Materials and Test Methods
The multi-arc ion plating technique was used to produce (TiZr) N hard films. Two arc sources with different orientations and configured at 90 degrees are used for simultaneous arc deposition. One of the arc sources is a commercially pure titanium target with a purity of 99.9% or a pure zirconium target; the other is a commercial titanium-zirconium alloy target with a purity of 99.9%. The atomic ratio of the titanium-zirconium alloy target is Ti:Zr=50:50. The polished high-speed steel block was used as the substrate. Prior to the official deposition of (TiZr) N hard film, ion bombardment cleaning was performed. When the vacuum level of the coating chamber back reaches 8.0×10-3 Pa and the temperature reached 200°C, argon gas was charged to make the vacuum degree in the coating chamber reach 2.5×10-1 Pa, then two arc sources are turned on, arc current is maintained at 55-56 A, ion bombardment is performed for 10-12 min, bombardment bias voltage is gradually increased from 350 V to 400 V, and metal transition layer deposition is performed after bombardment cleaning. The argon pressure in the coating chamber is maintained at 2.0×10-1 Pa. The arc currents of the titanium target, zirconium target, and titanium-zirconium alloy target are all set at 55 A to 60 A, and the workpiece bias is 190 V to 200 V, the deposition time is 5min. Then, the (TiZr) N hard film was deposited and the deposition bias was set to 160±2V. The specific deposition process of (TiZr) N hard film is shown in Table 1.
Table 1. Deposition process parameters
|Target Current (A)|
Study on Deposition Process of (TiZr) N Hard Film
The surface morphology, fracture morphology, and film composition of the (TiZr)N hard film are all analyzed by a HITACHIS-3400N scanning electron microscope (energy spectrum). The phase structure of the TiZrN film was determined by the X-ray diffractometer with the Jade 6.5 electronic PDF card. Surface hardness is tested by the HXD-1000TMB / LCD LCD display automatic turret microhardness tester, load of 10gf, load retention time of 20s. Adhesion and friction coefficient are tested by the multi-functional material surface performance tester (MFT-4000).
In the process of depositing (TiZr) N hard film by using Zr target and Ti target combination or Zr target and Ti-Zr target combination, the limited fluctuation of process parameters such as cathodic arc current, N2 flow rate and so on will not have a significant effect on the surface composition of the film, the microstructure of the film, and the mechanical properties of the (TiZr) N hard film. The produced (TiZr) N hard film has advantages such as high hardness, strong adhesion, low friction coefficient, etc. And the deposition process window has good applicability.