Combined Processing of Micro Cutters Using a Beam of Fast Argon Atoms in Plasma

Alexander Metel,Petr Pivkin,Ilya Minin,Yury Melnik,Enver Mustafaev

doi:10.3390/coatings11040465

Alexander Metel, Petr Pivkin + Show 3 more

Open Access

https://doi.org/10.3390/coatings11040465

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Abstract

We present a new method for coating deposition on micro cutters without an increase in their cutting edges radii caused by the deposition. For this purpose, the cutting edges are sharpened before the coating deposition with a concentrated beam of fast argon atoms. The sharpening decreases the initial radius and, hence, limits its value after the coating deposition. The concentrated beam of fast argon atoms is generated using an immersed in the gas discharge plasma concave grid under a negative high voltage. Ions accelerated from the plasma by the grid pass through the grid holes and are concentrated in the focal point of the grid. As a result of the charge exchange in the space charge sheaths of the grid, they are transformed into fast atoms. A uniform sputtering by the fast atoms of the micro-cutter surface reduces the radius of its cutting edge.

Highlights

The useful life of cutting tools substantially increases after the deposition of thin wear-resistant films [1,2]
The droplets can be removed from the plasma by transformation of radial plasma streams emitted by the arc cathode spots on the side surface of a cylindrical cathode into an axial stream by means of “single bottle neck” magnetic field [16]
The above results showed that the etching of end mills with a fast atom beam allows an appreciable sharpening of the tools

Summary

Introduction

The useful life of cutting tools substantially increases after the deposition of thin wear-resistant films [1,2]. In the case of micro tools, their cutting edge radii will increase by 2–2.5 times, which will not allow a stable cutting process In this case, an increase in the thickness of the cut chips is impossible, because micro cutters are small and have a lower ability to resist bending, which promises their destruction when bending. There is a limitation on the maximum feed per tooth value, and there is a minimum feed per tooth limit by the minimum chip thickness The latter relates to the minimum allowable cutting edge radius that must be met for a stable cutting process. The only way to increase the useful life of micro cutters without losing the cutting process stability in conditions of parametric tool failure is to reduce the cutting edge radius. The etching will allow reduction of the coated tool radius lower than the radius of the initial tool

Experimental

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Discussion

Conclusions