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Cutting forces when milling fibre reinforced composites
Martének, Libor ; Forejt, Miloslav (referee) ; Humár, Anton (advisor)
The thesis is focused on composite materials with a view to their classifi-cation, identification, usage, current trends in production and development and possibilities of effective machining. As a part of this thesis, there is an evaluation of experimentally measured values during technological testing of milling of a fibre reinforced composite with a polyester matrix reinforced by fiberglass. The technological testing was performed with a view to measure certain values, i.e. impact on machined material, working conditions for a tool and its abrasion equal to the values of components of cutting force. From the values obtained from the testing, a general analysis of cutting force when milling was created containing overall technical and economical evaluation.
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On the cutting performance of selected HSS drills
Med, Slavomír ; Dvořáková, Jana (referee) ; Píška, Miroslav (advisor)
The bachelor thesis aims on a twist drill. In the theorical part characterizes the parts of drill bit and presents its fabrication from fabrication of cutting material to coating. This part finishes by description of contemporary methods of measuring of cutting performance. The main goal of this thesis is to propose and realize measuring of cutting performance of which results we can compare selected HSS drill bits and recommend them to practice. The tests are described in the practical part which contains the evaluation of results too.
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Inconel 718 machining for aerospace applications
Urbánek, Vojtěch ; Osička, Karel (referee) ; Polzer, Aleš (advisor)
Bachelor thesis is aimed at exploring the properties, usage and issues with milling of the Inconel 718 for aerospace applications. In the theoretical part a study of superalloys and their properties for successfull application in aircraft engines was conducted. Further the machinability classes, cutting materials and process of milling focusing on milling of the Inconel 718 are described. The experimental part deals with measuring and evaluation of cutting forces when milling the Inconel 718 with cemented carbide and ceramic cutting tools.
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Simulation of cutting force during milling process with straight tooth plain milling cutter.
Zemčík, Tomáš ; Sedlák, Josef (referee) ; Zemčík, Oskar (advisor)
To make a simulation of cutting force during milling process with cilindrical cutter is the aim of this diploma thesis. Preliminary part is devoted to technology of milling, milling cutters and cutting materials. The next section is aimed at kinematics of the cutting process, a theoretical analysis of power proportion, the possibility of measurement of force actions. General information about the programming software, a theoretical simulation model, graphical environment of created application, are the other points of this diploma thesis. The work also includes evaluation of the experimentally measured values and compared with values obtained from the created application.
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Effective Machining Of Fiber Reinforced Composite Materials
Sedláček, Jan ; Janáč, Alexander (referee) ; Vrba, Vladimír (referee) ; Klement, Josef (referee) ; Humár, Anton (advisor)
The objectives for this dissertation are to push forward the current state of knowledge in the area of machining fiber-reinforced plastic (FRP). The most common machining operation performed on these materials is drilling owing to the need for component assembly in mechanical pieces and structures. Among the defects caused by drilling, delamination appears as to be of the most critical and may occur at both the entrance and exit plane. A number of theoretical and experimental studies have been made to create an analytical model of delamination in composite laminates. In this dissertation, the critical thrust force (force which initiates the delamination) is predicted using linear elastic fracture mechanics - assuming Mode I. Delamination is investigated by studying the evolution of feed force and torque applied by the tool on the workpiece. A four components piezoelectric dynamometer KISTLER 9272 with special PC-software is used for measuring and evaluating of torque and cutting forces, when drilling two different composite materials: carbon/epoxy laminate fabricated by hand lay-up technique and glass/polyester composite made by pultrusion. Wear mechanisms and location of the wear on the tool are also investigated (with respect to cutting material). The tool wear is measured with help of a common workshop microscope and recorded with scanning electron microscope PHILIPS XL30. Drilling experiments are performed to give complex technical information (i.e. cutting conditions, tool geometry, tool wear and so on) which enables efficient machining of composite materials. Delamination-free drilling is given special emphasis in the experiments. Methods of statistical analysis (DOE) are used to determine which factors have the most influence on delamination.
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On the testing of new cutting inserts performance
Kašpar, David ; Dvořák, Jaromír (referee) ; Píška, Miroslav (advisor)
The thesis is focused on bar peeling method which is used to eliminate surface defects of rolled and forged cross-section circular products. The theoretic part deals with bar peeling processes. In the practical part are performed short-term tests of current types of inserts, evaluation and identification of their shortcomings. Short-term tests of new types of inserts are also performed and evaluated. For the final testing in operating conditions, which is then performed are recommended the best inserts. Suggestions for improving production are also included.
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A study on the grinding of ceramic materials
Kresa, Jakub ; Sliwková, Petra (referee) ; Píška, Miroslav (advisor)
This thesis is focused on ceramics materials in terms of their partition, properties, structure, manufacture and methods of their possible machining. The first part of this thesis is devoted to the distribution of ceramics materials, their structure, properties, and methods of production. Currently, ceramics materials are increasingly used in structural (engineering) applications therefore we deal with methods of effective machining of ceramic materials, to achieve part of the required shape, dimensions and surface quality. The evaluation of ceramic grinding test from the point of view of cutting forces and surface quality of the machined faces are presented in the last part of the thesis. The tested materials have been provided by company SEEIF Ceramics a.s.
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Factors affecting the quality of machined surfaces after milling operation
Černý, Libor ; Jaroš, Aleš (referee) ; Fiala, Zdeněk (advisor)
This diploma thesis deals with the final quality of the surface under variable working conditions during milling. The first part deals with the definition of qualitative parameters describing surface properties. This is followed by a brief description of the cutting resistance measurements. The thesis is complemented by experimental verification using front milling and its evaluation. The aim of the experiment is to determine the dependence of the surface quality and the size of cutting resistors under the variable working conditions of the machine that do not make a common part of the manufacturing processes.
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