Tool geometry study in micromachining

Abstract

With the trend towards miniaturization, micromachining becomes more and more important in fabricating micro parts. Investigations have shown that unpredictable tool life and premature tool failure present a serious concern in micromachining. To further develop the process, a systematic study of various types of tool geometry has been carried out. The tool failure modes and the ways in which tool life can be improved were also studied. Experimental results show that the tool tip rigidity of the semi circle-based (D-type) end-mills is much higher than that of the two-flute (commercial type) end-mills, and the machining quality with the D-type tools is better than that of the triangle-based (-type) end-mills. The tool breakage of end-milling operations simulated using real tool geometry is in good agreement with experimental data. Both the experimental study and FEM analysis have shown that the D-type end-mills are more suitable for micromachining.

U-Line

“…The reason was to broaden the acceptance of the micro milling process because of the low process reliability and the frequent tool failure (Fang et al 2003;Uhlmann and Schauer 2005).…”

“…But Fang et al showed that most geometries with more than one cutting edge are not able to cut properly under micromachining conditions and, with every cutting edge of a USM mill, the torsional shear stress and the possibility of fatigue tool failure rise. This is the reason why most of the USM mills exist as singleedge tools (Fang et al 2003). The most common geometries with these single-edge tools are the micro end mill, the micro-tapered end mill, the micro torus end mill, the micro ball end mill, as well as the micro profile end mill, shown in Fig.…”

A study on the micro tooling for micro/nano milling

“…The best surface finish achieved by the SFB and SSB has approximately an Rz of 1.8 and 1.0 μm, respectively. In [6], Δ-type and D-type end mills are (Fig. 1f).…”

“…The reason is that inappropriate design and fabrication will result in the long tool fabrication time and high cost due to the complicated tool fabrication processes, and even worse, it reduces the geometrical accuracy of fabricated tools, subsequently with these tools, it is difficult to achieve acceptable micro machining accuracy and surface quality. Many studies have been performed to fabricate or optimize the geometry of the micro/nano milling tools [1][2][3][4][5][6][7][8]. Although some suggestions are given based on the specific tool geometries in the literatures, no guidance criterion has been introduced for the custom micro tool design.…”

Machinability study of steels in precision orthogonal cutting

“…Thus, it should be the first choice amongst various manufacturing processes. Furthermore, conventional machining processes such as turning, milling and grinding have already been well established [1][2][3][4] . On the other hand, as the feed rate and depth of cut are reduced, special attention must be paid to the cutting edge preparation, otherwise the chip will not be generated owing to the side flow effect.…”