Applied Machining Technology

Frontmatter

1. Introduction

Heinz Tschätsch, Anette Reichelt

2. Fundamentals of machining explained for turning

Abstract

The terms of machining, as well as tool wedge geometry are defined in the DIN standards 6580 and 6581.

Heinz Tschätsch, Anette Reichelt

3. Tool life T

Abstract

Tool life T is the period of time, expressed in minutes, for which the cutting edge, affected by the cutting procedure, retains its cutting capacity between sharpening operations. The cutting edge remains functional until a certain amount of wear has occurred (3.3).

Heinz Tschätsch, Anette Reichelt

4. Tool- and machine curves

Abstract

When cutting speed is mapped as a function of the sectional area of chip for a constant tool life in a log-log diagram (log v _c = f (log A); for T = const.), the result is a straight line (Figure 25), which is called the tool curve. “Werkzeug-Gerade”

Heinz Tschätsch, Anette Reichelt

5. Metal removal rate and chip volume ratio

Abstract

With regard to the metal removal rate, we have to distinguish between the volume of the removed material Q _w and the space needed for the randomly arranged metal chips Q _sp. The volume of the removed material identifies the volume occupied by a chip with cross section a _p · f (depth of cut multiplied with feed) and a defined length per minute.

Heinz Tschätsch, Anette Reichelt

6. Cutting materials

Abstract

Cutting tools are subjected to enormous strain. Their cutting characteristics depend on the cutting material selected. Due to the interaction between the material to be removed and the cutting material, the following materials are used depending on type of the metal removal procedure, cutting method, desired tool life, required temperature resistance etc.

Heinz Tschätsch, Anette Reichelt

7. Turning

Abstract

Turning is defined as a metal cutting technology in which the cutting movement is carried out by the workpiece, whereas the tool performs the auxiliary motion (feed and infeed). Feed and infeed are done using longitudinal- and cross slides in most lathes (Figure 7.1). When turning very thin parts, the workpiece is supported at the point of processing, and feed motion is carried out by the headstock.

Heinz Tschätsch, Anette Reichelt

8. Planning and slotting

Abstract

Planing is a cutting technology in which the workpiece is machined in slices with a single blade tool, the planing tool.

Heinz Tschätsch, Anette Reichelt

9. Drilling

Abstract

Drilling is a cutting procedure designed to generate holes predominantly with a two-flute tool, the twist drill. When drilling on the drilling machine, the tool carries out the feed- and the cutting motions. If the hole is machined on a turning- or automatic lathe, then the workpiece performs the cutting motion.

Heinz Tschätsch, Anette Reichelt

10. Sawing

Abstract

Sawing is a metal cutting procedure in which the multi-edged tool carries out both the cutting and the feed motions.

Heinz Tschätsch, Anette Reichelt

11. Milling

Abstract

Milling is defined as a metal cutting technology in which a multi-edged tool removes the metal.

Heinz Tschätsch, Anette Reichelt

12. Broaching

Abstract

Broaching is a metal cutting technique with a multi-edged tool in which the tool performs the cutting motion. This method functions without any feed motion due to the offset of the cutting teeth on the broaching tool.

Heinz Tschätsch, Anette Reichelt

13. Grinding

Abstract

Grinding is a metal cutting procedure in which a multi-edged tool, whose cutting edges are geometrically undefined, removes the chips.

Heinz Tschätsch, Anette Reichelt

14. Abrasive cutting

Abstract

Abrasive cutting is a grinding procedure which is exclusively intended for parting off material, as in sawing.

Heinz Tschätsch, Anette Reichelt

15. Abrasive belt grinding

Abstract

During abrasive belt grinding, an endless grinding belt runs on 2 or more rollers (Figure 15.1). The roller, for which the method is named and on which contact between grinding belt and workpiece occurs, is referred to as the contact wheel.

Heinz Tschätsch, Anette Reichelt

16. Honing

Abstract

Honing is the finest grinding method with bound abrasive grain and longitudinally oriented bonded abrasive segments (honing stones).

Heinz Tschätsch, Anette Reichelt

17. Superfinishing (shortstroke honing)

Abstract

The superfinishing method, also called superhoning or shortstroke honing, is a precision finishing pro- cess in which a workpiece rotates and an abrasive wheel, which is pressed against the workpiece, simultaneously performs a rapid longitudinal vibration of only few millimetres (Figure 17.1).

Heinz Tschätsch, Anette Reichelt

18. Lapping

Abstract

Lapping is a precision grinding technique with loose grains, in which the workpiece and the tool slide over each other in constantly changing directions.

Heinz Tschätsch, Anette Reichelt

19. Further refinement of the cutting materials

Abstract

The outstanding characteristics of high-speed steels are:

• Great toughness,
• Low-cost,
• Sound machinability of the cutting material.

Heinz Tschätsch, Anette Reichelt

20. High speed cutting (HSC)

Abstract

In certain contexts, high speed cutting is only defined as machining at high cutting speeds (spindle speeds) and/or at high feed rates in order to achieve short machining- or lead times. However, for a reasonable classification, one has to consider the material to be machined (soft- or hard machining), the cutting materials and the metal removal rate.

Heinz Tschätsch, Anette Reichelt

21. Cutting fluids (coolants and lubricants)

Abstract

The energy used in the cutting process is almost exclusively transformed into heat, which means, depending on the method, that this thermal energy appears in the workpiece, the chip and the tool to different extents. During high speed milling, as explained in Chapter 20, it is possible to discharge the energy almost completely with the chip.

Heinz Tschätsch, Anette Reichelt

22. Cutting force measurement in machining

Abstract

New materials are being developed at a rapid pace, and particularly the constant refinement of cutting materials, tools and machine tools calls for up-to-date reference tables for optimal technological values. The tables or recommended data made available by the tool- or material manufacturers are usually very general and do not take into consideration the conditions and experiences of individual production plants. Thus, in many cases, it is useful for users to determine cutting parameters on their own.

Heinz Tschätsch, Anette Reichelt

23. Tables for general use

Heinz Tschätsch, Anette Reichelt

Backmatter