1 Overview
The evolution of machining technology is moving towards higher efficiency, precision, flexibility, and environmental awareness. Among various machining methods, cutting (grinding) remains the most widely used. High-speed cutting has emerged as a leading trend in machining, becoming the mainstream approach. It is a crucial technological foundation for advanced manufacturing. The adoption of high-speed cutting technology significantly boosts productivity, improves processing quality, and reduces costs. The development of this technology depends on advancements in machine tools and tool materials, with tool material progress being a decisive factor. Research shows that during high-speed cutting, as cutting speed increases, cutting force decreases while temperature rises rapidly. After reaching a certain point, the rate of increase slows down. The main causes of tool damage include mechanical wear, friction, adhesion, chemical degradation, chipping, and plastic deformation under the influence of cutting forces and temperatures. Therefore, the key requirements for high-speed cutting tool materials are high-temperature mechanical properties, thermophysical characteristics, anti-adhesion, chemical stability (such as oxidation and diffusion), thermal shock resistance, and resistance to coating cracking. Over the past two decades, numerous tool materials suitable for high-speed cutting have been developed, enabling machining of various workpiece materials under different conditions. For example, aluminum alloys (Si content ≤12%) can be cut at 2500–5000 m/min, cast iron at 500–1500 m/min, steel at 100–400 m/min, hardened steel and heat-resistant alloys at 90–200 m/min, and titanium alloys at 300–1000 m/min. Researchers also aim to achieve ultra-high cutting speeds for even better results.
2 Progress and Application of Foreign High-Speed Cutting Tool Materials
When performing high-speed cutting, optimal results depend on selecting appropriate tool materials and permissible cutting conditions for different workpieces. For commonly used materials like aluminum alloys, cast iron, steels, and heat-resistant alloys, developed tool materials include diamond, cubic boron nitride (CBN), ceramics, coated tools, and TiC(N)-based carbides (cermets).
Diamond tools, available in natural and synthetic forms, are known for their extreme hardness and thermal conductivity. Natural diamonds, though rare due to high cost and difficulty in processing, are still used in specialized applications such as micro-machining and aerospace components. Synthetic polycrystalline diamond (PCD) tools, made using high-pressure and high-temperature techniques, offer uniform hardness and excellent wear resistance, making them ideal for non-ferrous metals and composites. Advances in CVD diamond technology have led to new applications in woodworking and other industries.
Cubic Boron Nitride (CBN) is another superhard material, second only to diamond in hardness. It is highly resistant to thermal degradation and chemically stable, making it ideal for cutting ferrous materials. PCBN tools, which combine CBN particles with binders, are widely used for high-speed machining of hardened steels and cast iron.
Ceramic tools, including alumina and silicon nitride-based varieties, are popular for high-speed cutting due to their high hardness, wear resistance, and thermal stability. They are especially effective for machining high-hardness materials like hardened steels and cast irons.
Coated tools, such as those with TiN, TiCN, or Al2O3 layers, enhance performance by improving wear resistance and reducing friction. These coatings are applied using either CVD or PVD techniques.
TiC(N)-based hard alloys are known for their high wear resistance and toughness, making them suitable for high-speed machining of steels and alloys.
3 Challenges Faced by Domestic High-Speed Cutting Tool Materials
Despite significant progress, China’s high-speed cutting tool materials still lag behind international standards. Most high-speed cutting tools used in imported and domestically produced machines are imported, posing serious challenges for domestic tool development. Traditional high-speed steel (e.g., W18Cr4V) is still widely used, but its performance is limited. Advanced high-speed steels and powder metallurgy high-speed steels are underdeveloped. Ceramic tools, however, show promise, with several varieties matching global standards.
Domestic ceramic tools can process steels, cast irons, and alloys at high speeds of 300–1000 m/min. However, issues like poor surface finish and limited application remain. PCBN and PCD tools are also being developed, but their use is not yet widespread. Coated tools are gradually gaining traction, but there is still a gap in quality and variety compared to foreign products.
4 Future of High-Speed Cutting Tool Materials
The future of high-speed cutting lies in developing materials with superior high-temperature mechanical properties, chemical stability, and thermal shock resistance. PCD tools will continue to evolve, but synthetic single-crystal diamond and diamond thick films may replace them as costs decrease. In ultra-precision machining, natural diamond tools remain essential, though they may be gradually replaced by artificial alternatives.
Alumina and Si3N4-based ceramics, along with CBN tools, are expected to dominate high-speed cutting for steels and cast irons. However, each has its own limitations. Developing nano-composite ceramics and CBN-based composites could improve performance at extreme temperatures.
Coated tools, particularly those with advanced nanocoatings, hold great potential for high-speed machining. The development of powder coatings for reground complex tools is also promising.
For difficult-to-machine materials like titanium alloys, innovative cooling methods, such as nitrogen-based air cooling, could help reduce cutting temperatures and improve efficiency.
5 Conclusion
High-speed cutting technology has become the core of modern machining. Its rapid adoption brings significant economic benefits. Tool materials play a critical role in the success of this technology. Superhard materials, ceramics, TiC(N)-based carbides, and coated tools represent four major categories, each with unique advantages and applications. While China has made notable progress, especially in ceramic tools, there is still a gap compared to global leaders. By leveraging international technologies and focusing on new developments like CBN-composite ceramics and advanced coatings, China can accelerate the growth of its high-speed cutting tool industry.
Color Sorters,Cereal Color Sorter,Color Sorter Machine,Metal Color Sorter
Huade Heavy Industry Technology Co., Ltd , https://www.huadebaler.com