In the relentless pursuit of efficiency and longevity in industrial processes, a breakthrough in diamond coating technology is set to revolutionize the energy sector. Researchers, led by Guangyu Xu from the School of Mechanical and Materials Engineering at North China University of Technology, have developed a high-performance diamond coating for wire drawing dies that significantly extends their service life and improves drawing efficiency. This innovation, published in the journal *Jin’gangshi yu moliao moju gongcheng* (translated as *Metals and Nonferrous Metals Processing*), promises to reduce resource consumption and enhance productivity in energy-related manufacturing.
Wire drawing, a critical process in the production of wires used in various energy applications, demands high-performance tools to withstand extreme conditions. Traditional diamond-coated dies often suffer from peeling and surface roughness, limiting their effectiveness. Xu and his team tackled these challenges using hot filament chemical vapor deposition (HFCVD) technology to create diamond coatings on cemented carbide molds. “The key was to optimize the deposition process to improve adhesion strength and surface finish quality,” Xu explained. By systematically comparing the formation patterns of nano- and micron diamond coatings at different temperatures, the researchers discovered that temperature plays a crucial role in regulating the coating structure.
At 950°C, the high concentration of carbon active groups enhanced diffusion, leading to the formation of nano-diamond coatings. Conversely, at 900°C, micron diamond coatings predominated. However, the team found that neither type alone provided optimal performance. The nano-diamond coatings exhibited large delamination and shedding due to insufficient interfacial bonding, while the micron diamond coatings formed steps in the transition zone, causing intense friction and deep groove-like wear during drawing.
The breakthrough came with the development of a composite coating. By first depositing a micron diamond base layer and then an in situ nanodiamond surface layer, the researchers achieved a coating with strong interfacial bonds and a surface roughness of less than 50 nm after polishing. “The composite coating synergizes the advantages of high bonding strength of the bottom layer and low roughness of the surface layer,” Xu noted. This innovation resulted in a wire drawing die capable of achieving a drawing distance of up to 100 km, a significant improvement over the 50 km for single nano-diamond coatings and 15 km for micron diamond coatings.
The implications for the energy sector are profound. Wire drawing is a fundamental process in the production of wires used in power transmission, renewable energy systems, and other critical applications. The extended service life and improved efficiency of diamond-coated dies reduce the consumption of tungsten resources and lower production costs. “This process provides a reliable technical route to reduce resource consumption and promotes the large-scale industrial application of high-performance diamond-coated wire drawing dies,” Xu stated.
As the energy sector continues to evolve, the demand for high-performance, durable tools will only grow. This research not only addresses current challenges but also paves the way for future advancements in industrial manufacturing. By optimizing the deposition time of the micron and nano layers, further improvements in service life and cost reduction can be achieved, ensuring that the energy sector remains at the forefront of technological innovation.