|
|
Heat treatement of tool steels
Kubín, Matěj ; Moravčík, Igor (referee) ; Jan, Vít (advisor)
This thesis deals with heat treatment of tool steels. The work is divided into two parts. The theoretical part includes marking, properties and theoretical processing of tool steels. It also contains the technique which is used for sample preparation. In the experimental part there is an examination of the two common sold drills. Samples were made from the drill, on which metallographic analysis and heat treatment was performed.
|
|
|
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.
|
|
|
Relationship between Structure and Properties of cast Ni-alloys
Smékalová, Jana ; Hutařová, Simona (referee) ; Podrábský, Tomáš (advisor)
Nickel superalloys are developed for conditions which request the corrosion resistance, the heat-resisting and the creep-resisting material. They are used for components of air turbine motors and internal combustion turbines. The efficiency of these mechanisms is elevated with increasing combustion temperature so their development is accentuated. This thesis is concerned with a relationship between a structure and properties of nickel superalloys Inconel 713LC and Inconel 738LC in this thesis.
|
|
|
Heat treatement of tool steels
Kubín, Matěj ; Moravčík, Igor (referee) ; Jan, Vít (advisor)
This thesis deals with heat treatment of tool steels. The work is divided into two parts. The theoretical part includes marking, properties and theoretical processing of tool steels. It also contains the technique which is used for sample preparation. In the experimental part there is an examination of the two common sold drills. Samples were made from the drill, on which metallographic analysis and heat treatment was performed.
|
|
|
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.
|
|
|
Relationship between Structure and Properties of cast Ni-alloys
Smékalová, Jana ; Hutařová, Simona (referee) ; Podrábský, Tomáš (advisor)
Nickel superalloys are developed for conditions which request the corrosion resistance, the heat-resisting and the creep-resisting material. They are used for components of air turbine motors and internal combustion turbines. The efficiency of these mechanisms is elevated with increasing combustion temperature so their development is accentuated. This thesis is concerned with a relationship between a structure and properties of nickel superalloys Inconel 713LC and Inconel 738LC in this thesis.
|
|
|
The Changes in Structure of Steel P91 after Short Annealings
Král, Lubomír ; Čermák, Jiří ; Král, Petr
Phase composition of the steel P91 during annealing was studied with the aim to reveal the evolution of new phases. In this paper, the precipitation was characterized using energy-dispersive X-ray spectroscopy (EDS) and electron diffraction in transmission microscopy (TEM). Only Nb-rich particles were found in the studied samples austenitized at 1423 °C for 20h and water cooled. After tempering at 673 °C for 2 h, the formation mainly M3C type carbides and after tempering at 873 °C for 2 h, the formation of M7C3 and M23C6 was observed. These structure changes play an important role for stability and also carbon diffusion.
|
|
|
Measurement of Carbon Diffusion Coeficient - Calibration of Sputter Depth
Král, Lubomír ; Čermák, Jiří
Depth profiling mode of MiniSIMS device was applied to diffusion measurement. Calibration of crater depth was done using shearing interference microscope Zeiss Epival Interphako (ZEI) and confocal mikroskope Olympus LEXT OLS3100 with atomic force microscopy (AFM) modul. The ZEI uses one of the classical interferometric measuring methods. Generally this method leads to results with considerable experimental error. AFM is a very high-resolution type of scanning probe microscopy, with typical resolution of the order of fractions of nanometers, which is more than 1000 times better than the optical diffraction limit. However, the results taken by ZEI were in agreement with much more precise results of surface profiling achieved by AFM. It was found, at given experimental conditions (Fe-rich matrix, Ga + primary ions, 5 kV/3nA, DWT=1), that the sputter rate is some 0.3 nm per a single sputter scan of the crater area (50x50 µm). This depth calibration with SIMS technique can be applied to the study of carbon diffusion in BCC iron as an example. Special technique was developed, which avoids radio-tracer measurements with C-14. Obtained results are lower than the extrapolated values, which may be due to limited solubility of carbon in iron.
|
|
|
Plasmachemical synthesis of borides, carbides and nitrides of transition metals
Brožek, Vlastimil ; Ctibor, Pavel
For technical practice the most important are up to now borides of titanium and zirconium, carbides of boron, calcium, silicium, titanium, zirconium, hafnium, aluminum and chromium. Nitrides of boron, silicium and titanium. Besides of tungssten carbide, any of the mentioned compounds is proced presently in the Czech Republic, however the know-how and suitable conditions are existing. The contribution describes possibilities of the processing of the mentioned materials to functional layers or thin-walled shaped parts by plasmachemical methods.
|
|
| |
guest ::
