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Cutting Process and Tool Materials
Cutting is a process of material removal by means of a cutting tool. Cutting process is used in the manufacture of many products, including engine components, furniture, containers, structures and pre-formed shapes for subsequent assembly. During the cutting process, material is removed by means of applying a shear strain between the cutting edge of the tool and the workpiece. The shear strain is created through relative movement between the tool and workpiece, which causes the cutting tool to slice material away from the workpiece at a determined depth of cut. The cutting process can involve either producing chips or swarf, depending on the material being cut and the desired cutting result.
Most cutting operations involve the use of special purpose cutting tools, which come in a wide range of shapes and sizes. The choice of cutting tool material is critical, as it must be able to withstand the stresses and temperatures involved in the cutting process. Common tool materials used in cutting operations include high speed steel (HSS), tungsten carbide (WC), and ceramic-tipped tools.
High Speed Steel (HSS) is a type of tool steel composed of iron, chromium, tungsten, and vanadium. HSS tools are typically used for drilling, tapping, reaming, and thread cutting applications. The composition of HSS allows the tool to remain sharp when cutting at higher speeds, which makes it ideal for high-speed drilling and reaming applications. HSS tools are however not suitable for the cutting of materials such as stainless steel or when cutting at slow speed, as it can cause the tool to lose its hardness and resulting in a dull cutting edge.
Tungsten Carbide (WC) is a form of metal matrix composite composed of carbon and tungsten carbide. It is often used as a cutting tool material due to its extreme hardness and ability to withstand high temperatures. WC tools are most suitable for hard materials, such as stainless steel, cast iron and non-ferrous metals. As WC tools are harder than HSS, they can be used for machining operations at higher cutting speeds than HSS tools.
Ceramic-tipped tools are usually composed of a steel body embedded with ceramic particles. Ceramic tools are very hard and can withstand high temperatures, making them suitable for high speed cutting operations of hard materials. Ceramic tools can also produce finer surface finishes than HSS and WC tools and can reduce the wear rate of the tool. However, ceramic tools are not suitable for operations involving large depths of cut, as they may fracture when subjected to too much cutting forces.
In conclusion, the choice of tool material is essential in order to maximize tool life, cutting performance and surface quality in the cutting process. HSS, WC and ceramic-tipped tools are some of the common tool materials available and each have their own advantages and disadvantages. It is important to choose the most suitable tool material for the cutting application at hand in order to obtain the best cutting performance.
