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Geometrically defined cutting

Updated: Oct 9, 2023

According to DIN 8580, cutting manufacturing processes or separation process refer to the classification and description of separation processes in manufacturing technology. DIN 8580 defines various manufacturing processes and divides them into several groups based on their specific characteristics and applications.

Separation process includes various processes in which workpieces are divided into two or more parts by separating through materials. The most important processes in the main group of separation process are: geometrically defined cutting, geometrically undefined cutting (DIN 8589), splitting (DIN 8588), removing (DIN 8590), disassembling (DIN 8591) and cleaning (DIN 8592). These processes are used to bring workpieces into the desired shape or size, to remove materials and to create specific geometries, structures or surface quality. Separating processes with gradual material removal are exactly the opposite of additive manufacturing (3D printing), where the material is added layer by layer.

Geometrically defined cutting refers to a method of tool changing in metal cutting technology in which cutting tools with precisely defined tool geometries are used. This method makes it possible to take advantage of specific cutting geometries for specific cutting tasks by using different tools with different cutting geometries to transfer the mechanical energy from the cutting edge to the material. The cutting wedge angle refers to the angle between the cutting edge of the tool and the surface of the workpiece to be machined, and has a significant influence on chip formation, chip process control, tool wear and the surface quality of the machined workpiece.

Tool, chips, energy, workpiece, cooling and lubrication, wear, geometry

When geometrically defined cutting, the cutting tools are secured in special holders or clamping systems. The holders are designed to ensure the precise positioning of the cutting edges to enable precise machining. This precise positioning of the cutting edges is important to achieve optimal cutting performance and ensure the quality of the machined workpiece.

By using cutting tools with different geometries, various cutting tasks can be completed more efficiently. For example, tools with a specific cutting geometry can be used for roughing large amounts of material, while tools with a different geometry can be used for finishing surfaces or creating precise contours.

Geometrically defined cutting requires careful selection of the right tools and their correct positioning in the holders. It is important to consider the recommended cutting parameters for each cutting geometry to achieve optimal performance and minimize tool wear.

Overall, geometrically determined cutting offers a flexible and efficient way to handle different cutting tasks by using specific cutting geometries for specific applications.

Tool wear

Wear on tools can be caused by various factors. Here are some of the main causes of tool wear:

  1. Mechanical load: Tools are exposed to high mechanical loads during the machining process, such as pressure, friction and impact forces. These loads lead to micro-breaks, material deformation and cracking on the cutting edge, which ultimately leads to wear.

  2. Thermal stress: During machining, high temperatures arise due to the friction between the tool and the workpiece being machined. These temperatures can lead to material deformation, cracking and chemical reactions that accelerate tool wear.

  3. Chemical influences: Certain materials or machining environments can cause chemical reactions with the tool. Corrosion, oxidation or chemical wear can increase tool wear.

  4. Abrasive particles: The presence of hard particles, such as contaminants contained in the machined workpiece or materials with higher hardness, can lead to abrasive wear. These particles rub against the cutting edge and cause a gradual loss of material.

  5. Material properties: The material properties of the workpiece, such as hardness, toughness and lubricity, can influence tool wear. When machining hard or abrasive materials, wear is generally higher than with softer materials.

  6. Lubrication and cooling: Insufficient lubrication and cooling during the machining process can lead to increased wear. Adequate lubrication helps to reduce friction and heat generation and minimize tool wear.

Similarly, there are different types of wear that can occur on cutting tools and other components. Here are some of the most common types of wear:

  1. Adhesive wear: Adhesive wear occurs when materials adhere to the cutting edge of the tool due to high temperatures and pressures and then tear off. This leads to micro-breaks and loss of material on the cutting edge.

  2. Abrasive wear: Abrasive wear occurs due to the action of hard particles, such as impurities contained in the machined workpiece or materials with higher hardness. These particles rub against the cutting edge and significantly affect tool life.

  3. Erosive wear: Erosive wear occurs when a tool or surface is struck by solid particles or fluids under high pressure or high speed. This leads to erosion or damage to the surface.

  4. Chemical wear: Chemical wear occurs when the chemical composition of the workpiece or materials being machined reacts with the cutting material or cutting edge. This can lead to material separation, corrosion or chemical wear.

  5. Fatigue wear: Fatigue wear occurs under cyclic loading. Repeated stress can cause cracks, damage or deformation, which ultimately lead to component failure.

  6. Diffusion wear: Diffusion wear occurs when materials interact on the surface of a tool or component due to diffusion processes. This can lead to material replacement, deposits or changes in the material composition.

These types of wear can occur individually or in combination and depend on factors such as material properties, cutting conditions, lubrication, surface quality and other environmental influences. Knowledge of these types of wear is important in order to develop appropriate protective measures and tool coatings to reduce wear and extend the life of tools and components.


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