Prediction of tool wear constants for diamond turn machining of CuBe

2020 ◽  
pp. 251659842093099
Author(s):  
A. Sharma ◽  
D. Datta ◽  
R. Balasubramaniam

While several studies in diamond turning of homogeneous materials like Cu, Al, and Si are well published, there is a lack of understanding about tool wear in case of heterogeneous materials like CuBe. Severity of the tool wear can be understood from the magnitude of the wear coefficients, and the magnitude of these coefficients is influenced by the wear mechanism. Hence, this study is aimed to calculate the wear coefficients from a known tool wear model in diamond turn machining of CuBe. Molecular dynamics simulation (MDS) results show that stress and temperature are responsible for increasing rate of tool wear. From the experimental results, change in the tool cutting edge radius due to wear was obtained and the temperature and stress for various a/r were found out using MDS. With these data, the wear coefficients, A & B, from a wear model for diamond turning were calculated. This methodology of using MDS to obtain stress and temperature for various a/ r wherein, values of r are obtained from a single machining trial on actual material, will be useful for calculating the wear coefficients for the combination of single crystal diamond tool with various work piece materials and their activation energies.

1994 ◽  
Vol 116 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Tae Jo Ko ◽  
Dong Woo Cho

This paper introduces a fuzzy pattern recognition technique for monitoring single crystal diamond tool wear in the ultraprecision machining process. Selected features by which to partition the cluster of patterns were obtained by time series AR modeling of dynamic cutting force signals. The wear on a diamond tool edge appears to be classifiable into two types, micro-chipping and gradual, both very small compared to conventional tool wear. In this regard, we used a fuzzy technique in pattern recognition, which considers the ambiguity in classification as well as the weakness of the cutting force variation, to monitor the diamond tool wear status, with satisfactory results.


CIRP Annals ◽  
2015 ◽  
Vol 64 (1) ◽  
pp. 125-128 ◽  
Author(s):  
C.J. Evans ◽  
E.C. Browy ◽  
T.H.C. Childs ◽  
E. Paul

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 573
Author(s):  
Zhang ◽  
Guo ◽  
Chen ◽  
Fu ◽  
Zhao

The surface generation mechanism of the Cu alloys in ultra-precision diamond turning is investigated by both simulation and experimental methods, where the effects of the cutting parameters on the surface characteristics are explored, including the workpiece spindle speed, the cutting depth, the feed rate and the nose radius of the diamond tool. To verify the built model, the cutting experiments are conducted at selected parameters, where the causes of the error between the simulation and the machining results are analyzed, including the effects of the materials microstructure and the diamond tool wear. In addition, the nanometric surface characteristics of the Cu alloys after the diamond turning are identified, including the finer scratching grooves caused by the tool wear, the formation of the surface burs and the adhesion of graphite. The results show that the built model can be basically used to predict the surface topography for the selection of the appropriate machining parameters in the ultra-precision diamond turning process.


2012 ◽  
Vol 516 ◽  
pp. 437-442 ◽  
Author(s):  
Benjamin Bulla ◽  
Fritz Klocke ◽  
Olaf Dambon ◽  
Martin Hünten

Diamond turning of steel parts is conventionally not possible due to the high tool wear. However this process would enable several different applications with high economical innovative potential. One technology that enables the direct manufacturing of steel components with monocrystalline diamond is the ultrasonic assisted diamond turning process. This technology has been investigated over the years within the Fraunhofer IPT and is now commercialized by its spin-off company son-x. Surface roughness in the range of Ra < 5 nm can be achieved and the diamond tool wear is reduced by a factor of 100 or higher. In order to prove the industrial suitability of the process, two aspherical shapes and one large spherical geometry have been manufactured. The possible form accuracies and surface roughness values will be described in this paper, as well as the tool wear. The goal was to achieve optical surface roughness and a shape accuracy below 300 nm.


2019 ◽  
Vol 13 (2) ◽  
pp. 185-190
Author(s):  
Hideo Takino ◽  
Yoshimi Takeuchi ◽  
◽  

Waviness tends to be generated on cut surfaces even when an ultraprecision milling machine with a single-crystal diamond tool is used. The present study deals with the reduction of waviness by controlling the feeding mechanisms of the milling machine. A machining experiment on a spherical surface of a mirror element in a mirror array showed that the machined surface exhibited periodic waviness with a height of 30 nm and a wavelength of 300 μm. To investigate the reason for such waviness, a slope was machined under simultaneous multiaxis motion control of the feeding mechanisms of the milling machine. This proved that the interpolation errors of the encoders used in the milling machine produce the waviness on the machined surface when machining is carried out under simultaneous multiaxis motion control. To reduce such interpolation errors, the positioning accuracy of the machine stages was measured using a laser interferometer. On the basis of the measured results, the feeding mechanisms were compensated such that the positioning errors including the interpolation errors were corrected. Using the machine with the compensated feeding system, a mirror element was shaped. Consequently, waviness was reduced and the surface smoothness was less than 10 nm, demonstrating that such compensation can produce superior optical surfaces.


2019 ◽  
Vol 2019.56 (0) ◽  
pp. C033
Author(s):  
Kohei YANAMURA ◽  
Noritaka KAWASEGI ◽  
Noboru TAKANO ◽  
Noboru MORITA ◽  
Kazuhito NISHIMURA ◽  
...  

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