Failure of cutting tools? properties, hardness.

Types of Failure of cutting tools 

The failure of cutting tools can fail for a variety of reasons, including:

1. Wear.

2. Chipping or cracking.

3. Built-up edge.

4. Thermal damage.

5. Improper tool selection.

6. Improper cutting conditions.

7. Material defects

1. Wear: The cutting edge of a tool can become dull over time due to regular use, leading to a decrease in cutting efficiency.

2. Chipping or cracking: Cutting tools may be subjected to excessive force, which can cause the cutting edge to chip or crack.

3. Built-up edge: In some cases, material from the workpiece can accumulate on the cutting edge of the tool, leading to a decrease in cutting performance.

4. Thermal damage: Cutting tools can be damaged by excessive heat generated during cutting operations, leading to a loss of hardness and strength.

5. Improper tool selection: Using the wrong tool for a particular application can result in poor cutting performance and premature tool failure.

6. Improper cutting conditions: Operating a cutting tool at speeds or feeds that are too high or too low can cause premature wear or failure.

7. Material defects: Occasionally, cutting tools may have manufacturing defects that cause premature failure.

Properties of cutting tools 

The properties of cutting tools are essential for various industrial and manufacturing applications, such as machining, cutting, drilling, and shaping materials. They are designed to remove material from a workpiece, which requires them to possess specific properties to ensure they can perform their intended functions effectively. Some of the properties of cutting tools include:

Hardness: Cutting tools need to be hard to resist wear and deformation during the cutting process. They are typically made from high-carbon steel, cobalt, carbide, or diamond, which are materials that possess high hardness.

Toughness: Cutting tools also need to be tough to resist breakage and fracture during the cutting process. Toughness is a measure of a material's ability to withstand stress and strain without breaking or deforming.

Wear resistance: Cutting tools should have a high resistance to wear to maintain their cutting edge and prolong their lifespan. The tool material should be resistant to abrasion and erosion, which are common causes of wear.

Heat resistance: Cutting tools generate heat during the cutting process, which can lead to thermal deformation and wear. Therefore, cutting tools should be designed to resist heat and maintain their shape and cutting edge at high temperatures.

Chemical resistance: Cutting tools may come into contact with chemicals or corrosive materials during the cutting process. Therefore, they should be made from materials that are resistant to corrosion and chemical attack.

Sharpness: Cutting tools should be sharp to ensure they can cut the material efficiently and accurately. The cutting edge must be designed to maintain its sharpness for extended periods.

Durability: Cutting tools should be durable to withstand the forces and stresses of the cutting process. A durable cutting tool will last longer, require fewer replacements, and result in higher efficiency.

Stability: Cutting tools should be stable to ensure accuracy during the cutting process. Stability refers to the tool's ability to maintain its position and resist vibration and movement during cutting.

Machinability: The material used to manufacture the cutting tool should be easy to machine to reduce production time and cost.

In summary, cutting tools should possess properties such as hardness, toughness, wear resistance, heat resistance, chemical resistance, sharpness, durability, stability, and machinability to ensure they can perform their intended function. 

Tool materials: 

Tools can be made from a variety of materials depending on the application and the required properties of the tool. Here are some common materials used for making tools:

Steel: Steel is a common material used for making tools because of its strength, durability, and resistance to wear and tear.

Carbon fiber: Carbon fiber is a lightweight and strong material that is commonly used in high-performance tools such as racing bikes, aerospace components, and sports equipment.

Titanium: Titanium is a strong and lightweight material that is commonly used in high-performance tools, particularly in aerospace and military applications.

Aluminum: Aluminum is a lightweight and corrosion-resistant material that is commonly used for making tools such as wrenches and hammers.

Plastics: Plastics are commonly used for making tools because they are lightweight, inexpensive, and can be molded into a variety of shapes.

Ceramic: Ceramics are used for making cutting tools and abrasive materials because they are hard and wear-resistant.

Diamond: Diamond is the hardest known material and is used for making cutting and drilling tools 

Wear characteristics: 

There are several different types of wear that can occur, depending on the type of tool and the materials it is made from.

Abrasive wear: This occurs when the tool's cutting edge is worn away by the material being cut. It is common in tools used for machining hard materials like metal or stone.

Adhesive wear: This occurs when the tool's cutting edge becomes stuck to the material being cut, causing it to chip or break off. It is common in tools used for cutting soft materials like wood or plastic.

Fatigue wear: This occurs when the tool is subjected to repeated stress or impact, causing small cracks or fractures to develop over time. It is common in tools used for drilling or milling.

Corrosive wear: This occurs when the tool's surface is gradually eroded by chemical reactions with the material being cut. It is common in tools used for cutting materials like ceramics or glass.

Thermal wear: This occurs when the tool's cutting edge is damaged by high temperatures generated during cutting operations. It is common in tools used for cutting hard metals or alloys.