IMPACT OF THERMAL RADIATION HOT WIRE POWER ON THE QUALITY OF THE DIAMOND FILM DEPOSITED BY HFCVD ON POLYCRYSTALLINE DIAMOND COMPACT

The temperature field distribution uniformity has a crucial influence on growing high-quality diamond grains by hot-filament chemical vapor deposition (HFCVD). In this paper, we explored the effect of the temperature of the tungsten wire on the temperature field distribution on the surface of the polycrystalline diamond compact (PDC) substrate using the finite element method and found that, with the temperature of tungsten wire being 2200 ∘ C, it is suitable for the growth of diamond grains and the temperature distribution is more uniform. Meanwhile, the HFCVD method has been used to probe the effect of the parameters of the hot wire power on the diamond grains filling hole and the quality of the diamond film on the PDC surface, analyzed by various characterizations including SEM, XRD, Image J, and Raman. It turned out that both the size of the diamond grains and the acceleration of the deposition increase, as the hot wire power is increased. The size of the diamond grains decreases when the hot wire power is increased to 4.00[Formula: see text]kW, while the uniform and cauliflower-like nanodiamond films are formed. However, the hot wire power continued to increase and the deposition focused on the growing graphite phase rather than the diamond phase, resulting in a decrease in the quality and properties of the diamond film. The study was able to achieve good tenacity and wearability of the PDC for applications in oil drilling and ultra-hard coating tools.