FIGURE 11.4 Typical work materials used in micromilling in previous works

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High speed machining burrs. Finally, despite the fact that it has been stated that conventional machining centers maybe used in a satisfactory way for micromilling under particular conditions, machine tools that are designed explicitly for the mentioned aim are required to obtain the full benefits of this technology.
There are three different micromechanical machining methods commonly used. These are micromilling, microturning, and microhole drilling.
Microend milling represents one of the micromanufacturing processes that are important among micromechanical machining processes. Microfinger milling, which is the right scale reduction of macroscopic finger milling, can process three-dimensional elements with high depth ratios in one step. Micromilling tools of 1 mm or less have been accepted as microtools, and microtools 0.05 mm
(50 m) or less in diameter have been commercially manufactured in recent years.
The miniaturized end mills are highly affected by minor vibrations and extreme forces that may damage tool life and control of part tolerances. It is hard to identify damages on the cutting edges of the microfinger milling cutters as a result of these effects and even tool breakage. Some researchers have used various sensors and display systems to monitor tool wear and breakage.
In the case of microend milling, the speed of the tool per tooth is comparatively high in comparison with conventional milling. Therefore, it is critical how to create cutting conditions. If the cutting conditions are not appropriate, the break of the tool, which causes a waste of time and money, can occur quickly. For this purpose, cutting force analysis in microfinger milling plays a vital role in determining cutting characteristics such as tool wear and surface texture, cutting plans, and determination of cutting conditions
[19]
. It has become essential to measure the microcutting forces accurately and to improve the tool quality, as very extreme loads can be applied to miniature tools and even small vibrations have a significant effect on machining. Microcutting forces can be measured by using axis miniature force sensors
[19]
Microturning uses miniature turning tools with a diameter of up tom for producing microscale elements. Despite the fact that conventional and mi- croprocessing are similar in kinematics, there are significant differences in mechanics (chip removal mechanism. These differences are due to alterations in physical phenomena because of the scaling impacts related to tool geometry, tool material, and workpiece material characteristics.
Microturning systems have been developed for the production of microcy- lindrical parts. Workpieces with a diameter of 0.3 mm can be machined at a cutting depth of 15.000 rpm and 10 m. The machining accuracy of the mi- crolathes is determined to employ an optical microscope
[20]
. High precision values are reached by microturning, and this sensitivity is increasing day by day. The surface roughness value is significantly affected by cutting tool geometry and progress factors. Microtools are coated to improve cutting performances and wear resistance.
Microdrills are often utilized for the purpose of drilling smaller diameter through holes in the production of printed circuit boards for the miniaturization

Variants of high speed machining

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