Today cutting tools are used for variety of applications and have positioned themselves as significant equipments. Hence, it is vital to know about their characteristics and types.
Materials of the cutting tool must be equipped wit number of vital properties to prevent excessive wear, fracture failure and high temperatures in cutting.
The following characteristics are critical for cutting materials in order to pass through the heavy conditions of the cutting process and to develop high quality and affordable parts:
1) Toughness: The material should have ability to absorb energy without failing. If the cutting equipment fails soon that it is not strong enough.
2) Wear Resistance: There is a strong relation between hot hardness and wear resistance, latter depends more on hot hardness.
3) Surface Finish Of The Tool: It is also significant characteristics, which is chemical inertness of the tool material with respect to the work material.
4) Thermal Conductivity Of The Tool Material: It is affected by which maximum value of the cutting temperature at tool-chip interface.
Cutting tool materials
Carbon Steels is the oldest of the tool material. The carbon content is 0.6~1.5% with small quantities of silicon, chromium, manganese, and vanadium to refine grain size. Maximum hardness is about HRC 62. These materials possess low wear resistance and low hot hardness. The application of these materials is now limited.
High-speed steel (HSS) is another material, which was first produced in 1900s. They are alloyed with vanadium, cobalt, molybdenum, tungsten and chromium. The aforementioned are added to elevate the hot hardness and wear resistance. It can be hardened to various depths by appropriate heat treating up to cold hardness in the range of HRC 63-65. The cobalt component lends the material a hot hardness value, which is much greater than carbon steels. The high toughness and good wear resistance makes HSS suitable for all type of cutting tools with complex shapes for relatively low to medium cutting speeds. The most widely used tool material today for taps, drills, reamers, gear tools, end cutters, slitting, broaches, etc.
Cemented Carbides has also paved way in many industries. It was debuted in the 1930s. Most important tool materials today; cemented carbide is recognized because of their high hot hardness and wear resistance. The main drawback of cemented carbides is their low toughness. These materials are developed by powder metallurgy methods, sintering grains of tungsten carbide (WC) in a cobalt (Co) matrix (it provides toughness). There may be other carbides in the mixture, such as titanium carbide (TiC) and/or tantalum carbide (TaC) in addition to WC. In spite of more traditional tool materials, cemented carbides are present as inserts generated by powder metallurgy process.
Materials of the cutting tool must be equipped wit number of vital properties to prevent excessive wear, fracture failure and high temperatures in cutting.
The following characteristics are critical for cutting materials in order to pass through the heavy conditions of the cutting process and to develop high quality and affordable parts:
1) Toughness: The material should have ability to absorb energy without failing. If the cutting equipment fails soon that it is not strong enough.
2) Wear Resistance: There is a strong relation between hot hardness and wear resistance, latter depends more on hot hardness.
3) Surface Finish Of The Tool: It is also significant characteristics, which is chemical inertness of the tool material with respect to the work material.
4) Thermal Conductivity Of The Tool Material: It is affected by which maximum value of the cutting temperature at tool-chip interface.
Cutting tool materials
Carbon Steels is the oldest of the tool material. The carbon content is 0.6~1.5% with small quantities of silicon, chromium, manganese, and vanadium to refine grain size. Maximum hardness is about HRC 62. These materials possess low wear resistance and low hot hardness. The application of these materials is now limited.
High-speed steel (HSS) is another material, which was first produced in 1900s. They are alloyed with vanadium, cobalt, molybdenum, tungsten and chromium. The aforementioned are added to elevate the hot hardness and wear resistance. It can be hardened to various depths by appropriate heat treating up to cold hardness in the range of HRC 63-65. The cobalt component lends the material a hot hardness value, which is much greater than carbon steels. The high toughness and good wear resistance makes HSS suitable for all type of cutting tools with complex shapes for relatively low to medium cutting speeds. The most widely used tool material today for taps, drills, reamers, gear tools, end cutters, slitting, broaches, etc.
Cemented Carbides has also paved way in many industries. It was debuted in the 1930s. Most important tool materials today; cemented carbide is recognized because of their high hot hardness and wear resistance. The main drawback of cemented carbides is their low toughness. These materials are developed by powder metallurgy methods, sintering grains of tungsten carbide (WC) in a cobalt (Co) matrix (it provides toughness). There may be other carbides in the mixture, such as titanium carbide (TiC) and/or tantalum carbide (TaC) in addition to WC. In spite of more traditional tool materials, cemented carbides are present as inserts generated by powder metallurgy process.
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