Smart Cutting Tools Used in the Processing of Aluminum Alloys

The processing of aluminum alloys in optimal conditions is a problem that has not yet been fully resolved. The research carried out so far has proposed various intelligent tools, but which cannot be used in the presence of cooling-lubricating fluids. The objective of the research carried out in the paper was to design intelligent tools that would allow a control of the vibrations of the tool tip and to determine a better roughness of the processed surfaces. The designed intelligent tools can be used successfully in the processing of aluminum alloys, not being sensitive to coolants-lubricants. In the research, the processing by longitudinal turning of a semi-finished product with a diameter Ø = 55 mm of aluminum alloy A2024-T3510 was considered. Two constructive variants of smart tools were designed, realized, and used, and the obtained results were compared with those registered for the tools in the classic constructive variant. The analysis of vibrations that occur during the cutting process was performed using the following methods: Fast Fourier Transform (FFT); Short-Time Fourier-Transformation (STFT); the analysis of signal of vibrations. A vibration analysis was also performed by modeling using the Finite Element Method (FEM). In the last part of the research, an analysis of the roughness of the processed surfaces, was carried out and a series of diagrams were drawn regarding curved profiles; filtered profiles; Abbott–Firestone curve. Research has shown that the use of smart tools in the proposed construction variants is a solution that can be used in very good conditions for processing aluminum alloys, in the presence of cooling-lubrication fluids.

Development of a methodical approach for uncertainty quantification and meta-modeling of surface hardness in white layers of longitudinal turned AISI4140 surfaces

The formation of thermally and mechanically induced near-surface microstructures in the form of white layers leads to different hardness properties in these areas. Therefore, this paper conducts systematic surface hardness measurements and uncertainty quantification utilizing the Monte Carlo Method (MCM) in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM). Furthermore, several meta-models describing the hardness course in relationship to the material depth are used to model this nonlinear relationship via machine learning. The evaluation and selection of the optimal model considers the trade-off between measurement uncertainty and prediction quality in terms of mean squared error (MSE). The resulting measurement uncertainty is to be used for the calibration of a non-destructive micromagnetic material sensor. This will then be implemented for in-process monitoring in the outer diameter longitudinal turning process. This should make it possible to detect white layers during machining and to avoid them accordingly by controlling the machine parameters. By means of a soft sensor, the corresponding target value is to be derived from the micromagnetic material sensor measurement.

Features of virtual duplicate creation of the turning process

The interdisciplinary approach of MC-SUITE implementation of the Industry 4.0 concept and the main requirements for digital models (virtual duplicates) of cyber-physical systems regarding virtual processes compliance to the real ones and the possibility of real-time operation have been described. The main condition for creating an adequate dynamic model of technological processing system (TPS) interaction with the cutting process has been defined and a model for such interaction for the longitudinal turning has been developed. On example of developed turning process structural scheme the possibility of describing the interaction of the TPS input parameters (cutting depth and longitudinal feed) with the output parameters (deformations in the respective directions) due to changes in the model internal parameters in a form of cutting force components have been demonstrated. Such representation of the model allows virtual turning process adjusting by specifying the cutting stiffness and functional dependences for the cutting forces components based on the results of intelligent analytical processing of the monitoring results of the TPS operation.

Comparison of Surface Roughness When Turning and Milling

The quality of a machined surface can be described by macro and micro parameters, like the size error, the form and position error or the surface roughness. The task of machining process planning is to find the best machining method and parameters, which ensure the required quality. In this article, the surface roughness in the case of turning and milling technologies is analysed. The effect of the cutting parameters (feed at turning and depth of cut at milling) and the tool parameter (corner radius) are investigated. The results are compared with the theoretical geometric model of surface roughness. In longitudinal turning as well as in constant Z-level milling, the geometric model of surface roughness is similar. The article presents whether the real surface roughness is similar too.

Comparison of the machinability of the 316L and 18Ni300 additively manufactured steels based on turning tests

This paper focuses on the machinability of additively manufactured steel alloys (316L stainless steel and 18Ni300 Maraging steel) by reference to their conventional metallurgical conditions. The machinability of both metallurgical conditions has been evaluated by longitudinal turning tests under laboratory conditions using two different cutting tool geometries (flat rake face and chip-breaker geometry) and covering different cutting speeds, depths of cut and feed values. Cutting forces, chip morphology and surface roughness were investigated as machinability indicators. The influence of chip-breaker on process performance was also analysed. For a comprehensive discussion of the results, microstructure, chemical composition, surface roughness and mechanical strength of both metallurgical conditions were studied. The paper quantitatively demonstrates that despite the higher mechanical strength of additively manufactured alloys, no significant power requirements were verified for the finishing cutting of tested alloys, when compared with conventional materials. Also noteworthy, is the surface quality improvement of the printed samples due to the most favourable conditions for chip formation. The usage of a chip breaker insert had higher impact on reducing required cutting energy than on controlling chip geometry.

Influence of Relative Displacement on Surface Roughness in Longitudinal Turning of X37CrMoV5-1 Steel

The shaping process of surface texture is complicated and depends on many factors and phenomena accompanying them. This article presents the author’s test stand for the measurement of relative displacements in a tool–workpiece system during longitudinal turning. The aim of this study was to determine the influence of edge radius on the relative displacement between the tool and workpiece. The cutting process was carried out with inserts with different edge radii for X37CrMoV5-1 steel. As a result of the research, vibration charts of the tool–workpiece system were obtained. In the range of feed 0.03–0.18 mm/rev, the values of the standard deviation of relative displacements in the x-axis were obtained in the range of 0.36–0.78 μm for the insert with an edge radius of rn = 48.8 μm. As a result of the work, it was determined that for the feed value of 0.12 mm/rev for all inserts, the relative displacements are the smallest. As the final effect, the formula for forecasting the Ra roughness parameter was presented.

Minimizing tool vibrations when turning metals, as a method of energy-efficient cutting

Taking into account the interrelated vibration dynamics of cutting and the temperature in the cutting zone allows you to determine the most successful state or cutting mode in terms of energy costs. Purpose of the work: by forming a consistent model, determine the most convenient mechanism for the mode of operation of the cutting system, in which the further wear of the cutting wedge will be stabilized, the cutting force will also be stabilized, as well as the temperature in the cutting zone and the vibration of the tool. The paper examines: The process of metal processing by cutting on a lathe for the case of longitudinal turning of the product. Research methods: The research consists of a series of field experiments on real equipment using a modern measuring stand STD. 201-1, as well as using an experimental complex developed by us. Results and discussion. The results of processing experimental data, in particular, the results of measuring cutting forces, temperature and tool vibrations, are presented. The mechanism of stabilization of the processing process due to the relationship between temperature and vibrations during cutting and the formation of a quasi-stationary cutting mode is experimentally proved. It is assumed that due to the practical application of the results obtained in the work, it will be possible to increase the energy efficiency of metal processing by reducing the energy cost of vibration of the cutting wedge.