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New Milling HSS Cutters for Roughing Operations
Jaroš, Aleš ; Janáč, Alexander (referee) ; Chladil, Josef (referee) ; Píška, Miroslav (advisor)
Dissertation thesis is focused on development, design and production of the new milling cutter which is used for roughing operations. High-speed steels, coating technology and milling technology are described in first chapters of dissertation thesis. The main part of this thesis is the design of the new milling cutter that has been designed on the basis of the machining simulation. The milling cutter is designed as a three-flute cylindrical end mill made of high speed steel. The each flute is composed of two special compensation edges. The compensation edges are used for reducing (at best suppression) tensile stress in the heel of the tooth. The milling cutter was made by lost wax technology, followed by grinding and thermal treatment. New designed tools were deposited by PVD coatings (e.g. (Al,Ti)N). Standard catalog milling cutters (producer ZPS - milling tools, Zlín, Czech Republic) were used for comparison the designed milling cutter. Carbon steel CSN 41 2050 (DIN 1.1191) was used for milling, which was carried out with using process liquid. The monitored parameters were force loading, flank wear and tensile stress during milling. The dynamometer Kistler was used for measuring force loading and data obtained during machining was used for stress analysis.
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Machining of thin-walled components on a CNC lathe
Veselský, Radim ; Kolomý, Štěpán (referee) ; Slaný, Martin (advisor)
This work was focused on the design and production of a clamping device for clamping thin-walled circular workpieces on a CNC machine. Cutting forces were measured using a dynamometer. From these forces the highest power was derived. The minimum clamping force for clamping the workpiece was calculated. Using simulation, the most suitable angle of spacing of the clamping surfaces was determined. Based on this finding, the jaws were designed and manufactured. 5 samples were processed. Three samples were machined in the original jaws, two samples were machined in newly manufactured jaws. Each jaw was clamped with two specified clamping pressures. The machined samples were scanned with an optical scanner and measured in a measuring program. A clamping simulation took place with the determined pressures of both jaws in the simulation program. Conclusions were drawn from the calculations and the verification experiment.
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Research of a Cutting Tool with a Diamond Active Part
Trčka, Tomáš ; Mrkvica, Ivan (referee) ; Chladil, Josef (referee) ; Polzer, Aleš (advisor)
The submitted dissertation is focused on research in the field of milling tools with a diamond active part when machining one of the difficult-to-machine materials (Ti-6Al-4V). The first chapters are dealing with a theoretical analysis of a given workpiece material and polycrystalline diamond (PCD) as a super-cutting material. One of the theoretical chapters is also focused on tool sharpening technologies, for which the hardness of a diamond is no longer a crucial factor. The main part of the dissertation is the design, construction and production of tools taking into account the technological design, along with the application of modern trends and technologies enabling innovation and progressive design – from the perspective of macro/micro tool geometry and insert sharpening technology. The research was focused on the application of own inserts on the insert rake face and specific sharpening technologies EDMG, WEDM and LASER. One modification of the face of the PCD insert with a laser was subsequently applied to prototype circle segment end mill. Detailed analysis of manufactured tools and workpiece material was performed by electron, optical and digital microscopy. The measured parameters in the subsequent analysis of the machining process were force loading, tool wear, temperature measurement using a thermal imaging camera and analysis of the machined surface in the form of microhardness and roughness measurements.
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Machining of hardened steels
Veselý, Ondřej ; Osička, Karel (referee) ; Jaroš, Aleš (advisor)
Diploma thesis on Machining hardened steels is focused on the analysis of longitudinal turning of hardened steel 14 109 by using a tool from PKNB in terms of measuring the force load using a dynamometer and then evaluating the surface quality. The theoretical part deals with the issue of turning technology, cutting materials and heat treatment of steel. In the practical part, the influence of cutting conditions on the resulting values was assessed during the experiment. Twelve samples with different combinations of cutting conditions were tested, then was selected a sample that met the criterion of combining minimum cutting forces values and surface quality. The experiment shows that force load values can be achieved twice less by combining cutting conditions with an appropriate combination.
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Selection of an optimal tool for the selected machining technology
Podstata, Jan ; Jaroš, Aleš (referee) ; Fiala, Zdeněk (advisor)
This thesis compares the properties of four types of replaceable cutting tool inserts from different suppliers during milling. The comparative factors are cutting force, material loss of the insert and the roughness of the resulting surface. The thesis is divided into two parts - a comprehensive overview of the current state of knowledge and an experiment. The first part analyzes the load, the possibility of its measurement, surface treatment of tools, milling cutters and replaceable inserts. The experiment took the form of measuring the load during face milling, measuring the surface roughness of the machined material and measuring the material loss of the inserts on an optical strain gauge. The replaceable cutting tool inserts were compared based on the performed measurements.
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Force loading of milling tools during the machining process
Švec, Michal ; Trčka, Tomáš (referee) ; Polzer, Aleš (advisor)
This thesis compares the force load of two kinds of cutting tool inserts while milling. The thesis is devided into two main parts – research and experiment. The research part is focused on the theory of the force load measuring, cutting tools and cutting tool inserts and their coating. 14 grooves were made with each cutting insert while the force load was measured. Constant cutting conditions were applied. The experiment was repeated four times for each kind of cutting insert. The aim of the thesis is to determine if both kinds of inserts mill with the same force load. The results reveal that one kind of cutting tool inserts mill with the force load higher up to 85 %.
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Force loading of milling tools during the machining process
Procházka, Luděk ; Slaný, Martin (referee) ; Polzer, Aleš (advisor)
The thesis deals with the problem of force loading during machining of thin-walled parts. In the theoretical part, the force load applied during milling and the possibility of measuring of the force loading during milling is analyzed. Further the work focuses on the machining of thin-walled parts, problems in machining of these parts and the possibility of eliminating these issues. The practical part deals with the design and realization of the measurement of the force load on the selected components. The thesis also presents a comparison of the simulation model of deflection of thin-walled parts with the values measured in real machining.
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Prediction of suitable cutting conditions for machining of main steels
Beneš, Ondřej ; Fiala, Zdeněk (referee) ; Jaroš, Aleš (advisor)
In this thesis is described machining of barrel steels and determination of the most suitable cutting conditions for this process. In the theoretical part was characterized cutting process and explained problems of VBD wear, chip formation and roughness of the surface. There were also explained most common cutting materials and in the last part were described CVD and PVD coating methods. In the experimental part was measured force load during turning. There was also tested eight carbide cutting inserts from SECO TOOLS. During the tests were measured additional surface roughness values and taken chip samples as well. From the evaluated load force data were determined optimized cutting conditions for machining barrel steels and most suitable type of cutting insert.
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Analysis of the force loading of the end mills with PCD considering their sharpening
Trčka, Tomáš ; Kalivoda, Milan (referee) ; Polzer, Aleš (advisor)
Measurement of the force loading is a significant type of measurement in mechanical engineering applied to analyse important aspects in the machining process. In addition to the determination of specific material constants, it is possible to analyse, for example, various machining strategies, geometries of tools or the degree of wear of the cutting edges of cutting tools. This master’s thesis deals especially with the last two mentioned aspects which are subjects of an experiment on end mills with PCD inserts sharpened by a different technology. In the introductory part the cutting forces are theoretically analysed along with their measurement possibilities and the technology of the production of the mills including their sharpening – WEDM and EDM-G. One chapter is concerned with the milling of plastic materials, as PVC was the material used for the workpiece during the experiment. The first experimental part is devoted to the analysis of sharpened tools followed by the measurement of forces using the piezoelectric dynamometer and the subsequent analysis of the influence of the different tool geometry. The last conducted experiment monitors how the overall cutting forces of individual end mills sharpened by different technology changed over specific milling time slots.
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On the milling technology of thin-walled parts for aerospace industry
Ohnišťová, Petra ; Polzer, Aleš (referee) ; Píška, Miroslav (advisor)
This thesis is focused on the analysis and on the design of the milling technology of the components for the aerospace industry which are characterised by a high aspect ratio, reduced stiffness and all covered by a high demand on the fatigue performance. This work includes the experimental verification of the proposed technology using CNC machining center, evaluation of surface structure using optical high-resolution 3D surface measurement system ALICONA, analysis of the force loading using KISTLER device, fatigue testing and fatigue fracture analysis.
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