Konfu team's coating suggestions


We are excited to share with you some invaluable insights about PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition) coating, prevalent processes utilized in the surface treatment of screw forming tools.


PVD is a vacuum-based coating process that relies on thin-film technologies. In this process, the coating material, typically in the form of atoms, is deposited onto a substrate by condensation, transitioning from the vapor phase to the solid phase. The main methods of PVD include thermal evaporation, plasma sputtering, and ion beam sputtering. The substrate being coated usually undergoes temperatures in the range of 200-400°C. This is a considerably lower range compared to the temperatures associated with CVD.


Several common PVD coatings include TiN, TiCN, TiAlN/AlTiN, and CrN. For instance, the TiN coating is highly suitable for high-speed steel. The addition of carbon enhances the hardness and surface lubricity of the TiCN coating compared to TiN. An aluminum oxide layer fortifies tools with TiAlN and AlTiN coatings, increasing their lifespan in high heat applications.


CrN coating is known for its exceptional toughness and commendable resistance to corrosion. The low deposition temperature of CrN coating makes it ideal for materials that cannot withstand the higher temperatures required for other PVD coatings.


On the other hand, CVD is a coating process that results in thicker layers and involves significantly higher pressure and temperature. Here, the coating film transitions from the gas phase to the solid phase as a result of a chemical reaction induced by heating the substrate.

Plasma CVD is a vacuum thin film deposition process conducted at lower temperatures, ranging from room temperature to 350°C. It is extensively utilized in the semiconductor industry due to its higher efficiency and lower cost. This process employs plasma to provide the energy required for deposition reactions. However, when compared to thermal CVD, the wear resistance of Plasma CVD is somewhat limited.


Thermal CVD is a more conventional method used in the screw industry. It operates at temperatures between 700-1000°C, a range in which many substrates are not stable. An advantage of thermal CVD is that it achieves a high deposition rate, enabling the easy attainment of thick coatings. Unlike physical deposition, it is not limited by a line-of-sight deposition and can effortlessly coat holes and recesses.


The optimal coating choice largely depends on the material in question, the working environments, and operating conditions. Occasionally, it may necessitate some testing to determine the most suitable approach. We trust that this information will guide you in making informed decisions about your coating needs.