Performance and Application of Several New Grades of Cemented Carbide
Cemented carbide, the “tooth” of modern industry, has a direct impact on cutting efficiency and processing quality due to its performance. In recent years, with the development of new materials technologies, a number of new cemented carbide grades have emerged, achieving breakthroughs in wear resistance, toughness, and high-temperature resistance, meeting the cutting requirements of difficult-to-machine materials such as high-temperature alloys, titanium alloys, and composite materials. These new grades achieve enhanced impact resistance while maintaining high hardness through optimized composition design (such as the addition of rare metal carbides like TaC and NbC) and improved preparation processes (such as ultrafine grain technology and gradient structure design). This has broadened their application in high-end fields such as aerospace, new energy, and precision manufacturing.
WC-Co-TaC ultrafine-grained cemented carbide (such as the new grade YG10X-UF) is a new material developed for machining high-strength steel and titanium alloys. Its average grain size is controlled at 0.5-0.8μm, 30%-50% finer than traditional YG10. This grade boasts a hardness of HRA91.5 and a flexural strength of ≥2400MPa, combining high wear resistance with high toughness, overcoming the “hard but brittle” drawbacks of traditional cemented carbide. When machining TC4 titanium alloy, YG10X-UF tools can achieve cutting speeds of 80-100m/min, a 40% increase over standard YG10, extending tool life by 2-3 times. It is particularly well-suited for high-speed finish turning of thin-walled titanium alloy parts. In the machining of aircraft engine casings, this grade of tool effectively suppresses built-up edge (BUE) and maintains surface roughness below Ra0.8μm, meeting the machining requirements of precision parts.
Ti(C,N)-Al₂O₃ -based cermet carbide (such as the new MT-C300 grade ) is an ideal choice for high-temperature alloy machining due to its excellent high-temperature resistance and chemical stability. This grade utilizes Ti(C,N) as the hard phase and Al₂O₃ as the binder phase, with small additions of elements such as Mo and Ni to optimize performance. It boasts a room-temperature hardness of HRA92 and maintains a hardness exceeding HRA85 at 800 °C. Its oxidation resistance reaches 1000 °C, significantly exceeding that of traditional WC-Co alloys. When machining GH4169 high-temperature alloy, MT-C300 tools can achieve cutting speeds of 120-150 m/min , a 50% increase over coated carbide . The tool exhibits no significant adhesive wear during cutting, ensuring consistent part dimensional accuracy. In the mortise and tenon machining of gas turbine blades, this grade of tool can increase feed rates to 0.15 mm/min, significantly improving efficiency while reducing tool changes and lowering production costs.
Gradient-structured carbide, such as the new GC1030 grade, achieves a combination of high surface hardness and high core toughness by controlling the compositional differences between the surface and core, making it suitable for interrupted cutting and heavy-load machining. Its surface layer (5-10μm thick) is rich in WC, achieving a hardness of HRA93; the core, with an increased Co content of 10%-12%, achieves a flexural strength of ≥2200MPa and a 30% improvement in impact resistance compared to homogeneous carbide. In rough turning of automotive transmission gears, GC1030 tools can withstand the impact of the gear blank’s hard surface, achieving no chipping at depths of cut up to 3-5mm, and boasting a lifespan 2.5 times that of conventional carbide. For machining high-strength cast iron (such as ADI ductile iron), this grade offers an even better balance of wear resistance and chipping resistance, enabling “turning instead of grinding” with surface roughnesses reaching Ra1.6μm, reducing the cost of subsequent grinding operations.
Nano-coated carbide, such as the new NC5010 grade, further enhances tool performance by depositing multiple nano-coatings (e.g., a TiAlN/TiN multilayer structure) onto an ultrafine-grained carbide substrate. The coating is 3-5 μm thick, with each layer 5-10 nm thick. It boasts a hardness of HV 3500-4000, a coefficient of friction as low as 0.3, an oxidation resistance temperature of 850°C, and a bond strength with the substrate ≥80N. When machining carbon fiber reinforced plastic (CFRP), NC5010 tools effectively reduce fiber tearing and resin adhesion. Cutting speeds reach 300-400 m/min, two times faster than uncoated tools, and hole dimensional accuracy is controlled to IT7 level with a burr-free surface. In high-speed milling of aluminum alloy smartphone casings, this grade of tool achieves feed speeds of up to 5000 mm/min, achieving a mirror finish (Ra 0.05 μm), meeting the stringent requirements for exterior finishes.
Powder metallurgy high-speed steel-based cemented carbide (such as the new PHS-60 grade) is a new composite material composed of powder metallurgy high-speed steel (HSS) with a dispersed distribution of WC particles (30%-40% by volume). It combines the toughness of HSS with the wear resistance of cemented carbide, making it suitable for the manufacture of complex tools such as taps and broaches. Its room temperature hardness is HRC65-68, and its impact toughness is ≥15J/cm², a 50% improvement over HSS. Its wear resistance is 3-4 times that of HSS. When threading high-strength steel (such as 42CrMo), PHS-60 taps have a lifespan of 500-800 taps, three times that of HSS taps, while maintaining consistent thread accuracy (6H grade). When broaching mold steel (such as Cr12MoV), this grade of broach can increase feed rates to 0.1mm/tooth, improving processing efficiency by 40%. This also reduces tool sharpening times and reduces production downtime.
