02/12/2019

Sharp cutting edge - The resistance of the cutting edge and its service life are decisive

The performance of modern cutting tools has increased enormously in the last years. In order to meet the resulting tool requirements, the cutting edge architecture is moving closer into the focus of tool manufacturers.

In order to optimize the cutting edge for a production application, tool manufacturers use different edge preparation methods. Nevertheless, the advantages of the generated cutting edge architectures are only economically available with reproducible preparation processes. Accordingly, precise process and quality monitoring is of key importance in tool manufacture and preparation. While in the past it was usually sufficient to determine the mean edge radius, modern architectures require the monitoring of different properties such as the cutting edge microstructure and its shape, the three-dimensional edge topography and the chipping.

As a result of the complex measuring conditions resulting from inaccessible and reflective metal surfaces as well as measurement parameters in the μm range, measuring systems often reach the limits of what is physically possible.

In optical measuring systems, physical radiation effects are used to image measurement objects without contact. This generally eliminates the stylus problem that occurs with tactile measuring systems, and the systems are ideally suited for in-process or quality assurance tasks in tool manufacture. The measuring accuracy is affected by the physical reflection and diffraction properties of the tool surface. For example, blasted surfaces often have a matt, easily detectable topography, while brushed or coated surfaces often reflect very strongly. The choice of the measuring method depends above all on the spatial extent of the tool cutting edge to be monitored, because the maximum measuring ranges of the individual methods differ strongly.

Important parameters for the characterization of the cutting edge are determined automatically in order to obtain reproducible results without operator interaction. A representative 2D contour, for example, can be generated from profiles and used for numerical evaluation. In this way, the mean radius as well as any micro chamfers and their micro radii can be determined. The effective rake angle and the critical rake depth in the radius region can also be specified. Wedge, rake and clearance angles can be automatically measured in a defined clamping situation. Only these parameters allow the determination of the effective rake angle, which determines the cutting edge stress, taking into account the spatial tool positioning during operation. In addition, surface quality and chipping can be evaluated directly as roughness values of the corresponding tool areas.

With FRT's MicroProf® a wide range of measuring tasks can be performed quickly, efficiently and intuitively. As an established standard measuring tool in modern 3D surface metrology, the MicroProf® has impressed our customers for many years, for example in the semiconductor, medical and automotive industries.

Due to our multi-sensor concept, the 3D surface measuring tools of the established MicroProf® series can be equipped with point and area sensors for topography measurement as well as with layer thickness sensors. This makes it possible to solve a measuring task with different sensors by performing a measurement with each sensor and combining the different results.

Depending on your requirements, the MicroProf® enables you to perform a quick overview measurement of the entire sample as well as high-resolution detailed measurements. Profiles can be inserted through the surface in any direction. In addition, the contour or the complete topography of components can be determined in 3D. Roughness, waviness, flatness or layer thickness can also be evaluated three-dimensionally and quantitatively. Further advantages of our optical measuring tools are fast measuring times and user-friendly operation, which enables the worker self-control. 

The comparison of all considered measurements is essential. This applies to single profiles as well as to complete three-dimensional surface areas. The formulas and processes for profile measurement specified in the DIN/ISO standards are applied analogously to the surface. Of course, the corresponding filter functions are also taken into account. The highlight here is a filter routine for calculating the corresponding roughness values for the use of a probe tip with selected geometry, since the optical data usually provide a significantly higher resolution than tactile data and are therefore not directly comparable with these. With the simulation of a probe tip, the comparison values for suppliers or customers are provided in addition to the better resolved data for their own production. 

Maintain flexibility for your future measurements and retrofit sensors quickly and easily if required, saving space, time and (last but not least) costs.

The universal MicroProf® surface measuring tool is available in different models. Depending on the size of the samples to be measured, you can select the system that provides the appropriate sample holder and travel range. In addition to the MicroProf® 100 table-top system, there are two larger models, MicroProf® 200 and MicroProf® 300, which are standalone systems. From manual measurement and evaluation to fully automated sample handling, measurement and evaluation, you can determine the level of automation yourself by selecting the appropriate software and hardware components.

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Do you have further questions or comments? Then contact us! Our experts will be happy to help you solve your measuring tasks.

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