Cutting tools play a crucial role in machining, with different tool materials offering various advantages and being suitable for specific machining scenarios. This article provides a detailed introduction to several common tool materials and their application characteristics, including High-Speed Steel (HSS), carbide, ceramic tools, coated tools, Cubic Boron Nitride (CBN) inserts, and diamond tools.
1. High-Speed Steel (HSS) Tools
- High-speed steel (HSS) is a high-alloy tool steel with added alloying elements, giving it good strength and toughness.
- HSS still occupies a significant position in the manufacturing of complex tools, especially for hole processing tools, milling cutters, threading tools, broaches, gear cutting tools, and other intricate tools.
2. Carbide Tools
- Carbide tools can be classified into tungsten carbide-based and titanium carbide (e.g., TiC(N))-based carbides.
- According to the ISO (International Organization for Standardization), carbide cutting tools are divided into three categories:
- K Category: Ranges from K10 to K40, suitable for processing cast iron, stainless steel, and non-ferrous metals.
- P Category: Ranges from P01 to P50, designed for machining steel.
- M Category: Ranges from M10 to M40, primarily used for stainless steel and difficult-to-machine alloys.
Comparison Between HSS and Carbide Tools
- Carbide tools offer higher hardness, wear resistance, and heat resistance.
- HSS tools have greater strength, toughness, and better machinability, making them suitable for manufacturing complex tools.
3. Ceramic Tools
- Ceramic tools are ideal for high-speed cutting, machining difficult-to-process materials, dry cutting, and hard cutting. Their high hardness and heat resistance make them an efficient option for machining.
4. Coated Tools
- Coated tools are prepared by coating a thin layer of refractory metal or non-metallic compounds with excellent wear resistance onto a carbide or HSS substrate with good strength and toughness using vapor deposition methods.
- The coating can also be applied to superhard material inserts, such as ceramics, diamonds, and cubic boron nitride (CBN), enhancing surface finish, hardness, corrosion resistance, and wear resistance.
5. Cubic Boron Nitride (CBN) Inserts
CBN inserts are known for their excellent machining performance and can be categorized into four structures:
- Solid Inserts: Highly wear-resistant with multiple cutting edges, suitable for deep cutting and high-speed cutting in roughing, finishing, and both continuous and strong intermittent operations.
- Strong Tipped Inserts: Anti-breakage, with edges that are resistant to chipping, suitable for cutting depths less than 3mm in roughing, semi-finishing, finishing, and weak intermittent or continuous operations.
- Full-Face Inserts: Suitable for a cutting depth of up to 0.5mm, ideal for continuous and light intermittent roughing and semi-finishing.
- Tipped Inserts: Suitable for cutting depths less than 0.5mm, applicable for weak intermittent and continuous finishing or semi-finishing.
- Performance Characteristics of CBN Tools:
- High thermal stability: Ideal for high-speed dry cutting.
- Chemical inertness: No chemical reaction with iron at high temperatures.
- Suitable for machining high-hardness materials.
6. Diamond Tools
Diamond tools offer extremely high hardness and wear resistance, a low friction coefficient, high elastic modulus, high thermal conductivity, low thermal expansion coefficient, and low affinity with non-ferrous metals. These characteristics make diamond tools widely used for precision machining of non-ferrous metals and non-metallic materials.