Interview Questions and Answers on Cutting tool materials
What are the different types of cutting tool materials?
The common cutting tool materials are: high speed steel (HSS), cemented carbide (carbide), ceramic, diamond and cubic boron nitride (CBN).
What is high speed steel (HSS)?
HSS is a type of tool steel that is used for making cutting tools. It is known for its high hardness, toughness and wear resistance, which makes it ideal for cutting at high speeds.
What are the advantages of cemented carbide over HSS?
Cemented carbide is harder and more wear-resistant than HSS, making it suitable for machining materials that are difficult to cut such as cast iron, stainless steel and high-temperature alloys. Additionally, carbide is more heat resistant, which allows for longer cutting times and higher productivity.
What are ceramics used for in cutting tools?
Ceramics are used for cutting tools in high-performance applications where high speed and high temperature cutting is required. Ceramic cutting tools are known for their high hardness, high temperature resistance, and high wear resistance.
What is the difference between diamond and CBN cutting tools?
Both diamond and CBN are superhard materials that are used for cutting tools. The main difference between them is the type of material they are best suited to cut. Diamond is best for non-ferrous materials, while CBN is better for ferrous materials. CBN is also more heat-resistant than diamond, making it more suitable for high-temperature cutting applications.
How does the choice of cutting tool material affect cutting performance?
The choice of cutting tool material affects cutting performance in several ways, such as: hardness, toughness, wear resistance, temperature resistance, and ability to retain sharpness.
What are the disadvantages of using HSS for cutting tools?
HSS has limited hardness and wear resistance, which limits its use to cutting materials that are relatively soft and non-abrasive. Additionally, HSS is not as heat-resistant as other cutting tool materials, which may result in a loss of hardness and cutting ability.
What is the difference between solid and coated carbide cutting tools?
Solid carbide cutting tools are made entirely of carbide material, while coated carbide cutting tools have a carbide substrate with a protective coating. The coating provides additional wear resistance and prolongs the life of the cutting tool.
What are the benefits of using ceramic cutting tools?
Ceramic cutting tools provide several benefits, including high speed cutting, high temperature resistance, high hardness, and high wear resistance. Additionally, ceramic cutting tools are lightweight and can be used in high speed machining applications.
What is the difference between surface-coated and through-coated cutting tools?
Surface-coated cutting tools have a coating on the surface, while through-coated cutting tools have a coating that extends all the way through the tool. Through-coated cutting tools are more wear-resistant and provide longer tool life.
What are the common coatings used on cutting tools?
Common coatings used on cutting tools include titanium nitride (TiN), titanium carbon nitride (TiCN), and aluminum oxide (Al2O3).
What is the difference between roughing and finishing cutting tools?
Roughing cutting tools are used for removing large amounts of material in a short amount of time, while finishing cutting tools are used for precise machining and creating a smooth surface finish.
What is the purpose of using coolant in cutting tools?
Coolant is used in cutting tools to reduce heat buildup, improve surface finish, and prolong tool life. It also helps to flush away chips and debris, and lubricates the cutting interface.
What is the role of tool geometry in cutting tool performance?
Tool geometry, such as the shape of the cutting edge, rake angle, and clearance angle, plays a crucial role in cutting tool performance. It determines the cutting forces, chip formation, and cutting temperature.
What is the difference between positive and negative rake cutting tools?
Positive rake cutting tools have a cutting edge that is inclined towards the direction of cutting, while negative rake cutting tools have a cutting edge that is inclined away from the direction of cutting. The choice of rake angle depends on the material being cut and the cutting conditions.
What is the purpose of tool life in cutting tools?
Tool life is a measure of the time a cutting tool can perform its function before it becomes worn or damaged and needs to be replaced.
What are the factors that affect tool life in cutting tools?
Factors that affect tool life in cutting tools include: material being cut, cutting speed, feed rate, depth of cut, tool geometry, and cutting conditions.
What is the difference between carbide and ceramic cutting tools?
Carbide cutting tools are made from a combination of carbide and a metallic binder, while ceramic cutting tools are made from ceramic materials. Carbide cutting tools are more
How does the cutting speed affect tool life in cutting tools?
The cutting speed affects tool life in cutting tools because increasing the cutting speed can increase the cutting temperature and cutting forces, which can result in increased tool wear and reduced tool life.
What is the difference between dry and wet cutting in cutting tools?
Dry cutting refers to cutting without the use of coolant, while wet cutting refers to cutting with the use of coolant. Wet cutting can improve tool life and surface finish, but it also adds the cost of coolant and the need for proper disposal of coolant waste.
What is the difference between roughing and semi-finishing cutting tools?
Roughing cutting tools are used for heavy material removal, while semi-finishing cutting tools are used for intermediate material removal. Semi-finishing cutting tools are typically used between roughing and finishing operations to improve surface finish and reduce cutting time.
What is the difference between single-point and multi-point cutting tools?
Single-point cutting tools have one cutting edge, while multi-point cutting tools have multiple cutting edges. Multi-point cutting tools are typically used for turning and facing operations, while single-point cutting tools are used for drilling and boring operations.
What is the difference between coated and uncoated cutting tools?
Coated cutting tools have a protective coating on the cutting surface, while uncoated cutting tools do not have a protective coating. Coated cutting tools can provide improved tool life and surface finish, while uncoated cutting tools are typically less expensive.
What is the role of tool coatings in cutting tool performance?
Tool coatings play a role in cutting tool performance by providing improved wear resistance, heat resistance, and reduced friction. This can result in longer tool life, improved surface finish, and improved cutting efficiency.
What is the difference between PCD and CBN cutting tools?
PCD (polycrystalline diamond) and CBN (cubic boron nitride) are both superhard materials that are used for cutting tools. PCD is best for non-ferrous materials, while CBN is best for ferrous materials. CBN is also more heat-resistant than PCD.
What is the difference between cutting tools for turning and cutting tools for milling?
Cutting tools for turning are used for operations such as turning, facing, and boring, while cutting tools for milling are used for operations such as milling, drilling, and tapping. The choice of cutting tool depends on the specific requirements of the machining operation.
What is the difference between indexable and solid cutting tools?
Solid cutting tools are made from a single piece of material, while indexable cutting tools have replaceable cutting inserts. Indexable cutting tools are more cost-effective and provide longer tool life, but they require more setup time and are more complex to use.
What is the difference between high-performance and general-purpose cutting tools?
High-performance cutting tools are designed for demanding cutting applications, while general-purpose cutting tools are designed for general machining operations. High-performance cutting tools are typically more expensive, but they provide improved cutting performance and longer tool life.
What is the difference between ground and unground cutting tools?
Ground cutting tools have been precisely ground to a specific geometry, while unground cutting tools have not been ground. Ground cutting tools provide improved cutting accuracy and surface finish, while unground cutting tools are typically less expensive