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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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Zkoušení penetrační vlastnosti vybraných ocelí s využitím nedestruktivního zkoušení
Příkazský, Erik
This diploma thesis deals with the problems of mechanical properties and cutting of steel. In the first part, thematerials are divided according to the concept. In the second part is described non-destructive testing of material by acoustic emission and tests of measurement of cutting abilities into various hard objects. The last part of diploma thesis includes individual measurement results and evaluation of results.
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On the analyses of cutiing tools coated with PVD coatings
Malý, Martin ; Osička, Karel (referee) ; Píška, Miroslav (advisor)
In this diploma thesis, literary research about drilling and coating technology focused on PVD coatings was performed. Furthermore, there is an overview of cutting materials. In the experimental part of the work, the attention is dedicated to tests of twist drills from cemented carbide and high-speed steel materials. For these drills, the feed force Ff and the cutting moment Mc were measured when drilling into austenitic stainless steel. At the end of this work, the technical and economic evaluation of the practical part is presented.
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On the increase of cutting performance of thread cutting taps with PVD coatings
Grygárek, David ; Fiala, Zdeněk (referee) ; Píška, Miroslav (advisor)
This diploma thesis deals with HSS cutting taps performance in combination with very hard and tribological PVD coating application and their contribution to increasing of cutting properties. Then is described the mechanisms and forms of cutting tool wear. The goal of the experimental part of the thesis was determine, compare and subsequently evaluate cutting properties of threading tools using taps with different types of PVD coatings. During realization of the experiment, constant cutting conditions have been ensured and the only variable were the different types of coating layers. The result of the experiment was measurement of cutting torques depending on time and rate of wear of cutting tools. Measured value are statistically processed and drawn conclusion.
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Cutting performance of very fine grained end mills
Uttendorfský, Aleš ; Humár, Anton (referee) ; Píška, Miroslav (advisor)
This diploma thesis consists of two parts. The theoretical part describes sintered carbides, their properties and manufacturing tools. Some selected problems of milling and its physical nature is discussed also. It also deals with the types and methods of tool wear testing. The aim is to compare the experimental properties of monolithic end milling cutters (short four cutting edges, uncoated carbides) of various grain sizes in two basic ways of milling - down-feed method and up-feed method. The measured values are evaluated by analysis in time series of the cutting forces and power.
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Enhancement of HSS tools cutting performance with PVD coatings
Medek, Martin ; Sliwková, Petra (referee) ; Píška, Miroslav (advisor)
Diploma work describes speed drill steels and its qualities before and after coating by methods PVD (Physical Vapour Deposition). The theoretic part is concerned with thermic processing of speed drill steels and their qualities with regard to individual alloying elements contained and its mechanical features. Second part of the theoretic part is concerned with particular methods of coating by the help of PVD technologies, kinds of coating with regard to additional elements and their qualities and surface treatments of coated material before and after its coating. The goal of the experimental part was the confrontation of cutting power features of cylindrical four-fluted face mills with straight shank, from speed drill steels non-coated and coated in two basic modes of milling – down-feed method and upfeed method. The results of measurements were interpreted by the help of four basic pictures (source values, power analysis, specific values). The result of all the experiment is that the application of PVD coatings enabled the increasing of cutting speed (with preservation of other cutting requirements) and led to decreasing of cutting force and cutting enforcements and extended durability of cutters.
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On the increase of cutting performance of thread cutting taps with coatings
Světlíková, Jitka ; Sliwková, Petra (referee) ; Píška, Miroslav (advisor)
This bachelor thesis deals with the process of cutting, the wear of cutting tools and the fact, that coating makes tools more durable and increases cutting power. The goal of the experimental part is to determine, compare and evaluate cutting features in the process of thread cutting with taps of different coatings. For the experiment invariable cutting conditions were chosen, the only variable is the type of used coating. The result of the experiment is the measurement of cutting torque dependent on time and the grade of the wear of cutting tools.
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