L21 Processing

What are advantages and disadvantages of machine technologies?

Advantages: high precision, good surface quality, wide range of geometries and materials. Disadvantages: material waste, high energy consumption, time-consuming, requires skilled labor.

What is the main difference between turning and milling?

In turning, the workpiece rotates and the tool is stationary; in milling, the tool rotates and the workpiece is stationary or moves linearly.

Which parameters describe the machining process?

Cutting speed (v), feed (f), depth of cut (d), feed rate (fr), tool geometry, material removal rate (RMR), machining time (Tm).

What is the difference between the feed f and the cutting velocity v?

Feed (f) is the linear distance the tool advances per revolution (mm/rev), while cutting velocity (v) is the speed at which the cutting edge moves relative to the surface (m/min).

Which parameters influence the chip formation?

Tool geometry, cutting speed, feed, depth of cut, rake angle, friction, and material properties.

What types of chips can be performed and which type is the most desirable one?

Discontinuous, continuous, continuous with built-up edge, serrated. Continuous chips are most desirable for good surface finish.

How does the tool geometry change between turning and milling?

Turning uses a single-point tool; milling uses a multi-tooth rotating cutter with different chip loads per tooth.

What are essential requirements for cutting materials? Which materials comply with these requirements?

Requirements: high toughness, wear resistance, temperature resistance, sharp edge retention. Materials: HSS, carbide, diamond.

What is the benefit of using CNC machines?

High automation, high precision, repeatability, ability to produce complex geometries, and reduced manual intervention.

How can abrasive processes be distinguished from classic machining like turning and milling?

Abrasive processes use hard particles to remove material without defined cutting edges; classic machining uses defined tools with specific geometry.

What are differences in the machinability of metals, plastics and composite materials?

Metals: good thermal resistance, predictable cutting. Plastics: low thermal conductivity, risk of melting. Composites: anisotropic, abrasive to tools, risk of delamination and dust formation.