This thesis is concerned with the microstructures and wear characteristics of eight ceramic tool materials which have been, or are currently, commercially available as indexable inserts for lathe tools. Two of the materials are alumina-based and the other six are derived from silicon nitride. The opening chapters of the thesis outline the essential features of metal cutting, the properties required of a good tool material, the development of ceramic tools and possible wear behaviour as discussed in the literature. Subsequent chapters describe the experimental procedures adopted in this work and both present and discuss the results obtained. The eight ceramics have been microstructurally characterised by the use of X-ray diffractometry, scanning electron microscopy and transmission electron microscopy. Machining tests have been performed using five common workpiece materials, spanning a range of nickel and iron contents: mild steel, stainless steel, two nickel-based superalloys and commercial purity nickel. The two alumina-based materials were found to wear in a different, less severe manner to the silicon nitride-based tools. The mechanical response to surface contacts was established using identation techniques to give hardness (as a function of contact size and temperature) and fracture toughness (as a function of temperature) to test the correlation between these properties and wear behaviour, but this proved to be unfruitful. Since other classes of tools can be subject to dissolution/diffusion wear and little is known about the compatability of these ceramics with molten metals, a second type of investigation was instigated. The involved immersing pieces of ceramic in samples of molten workpiece materials, followed by cooling, sectioning and examining in the scanning electron microscope. Vast differences in the behaviour of the materials were observed and results from these tests correlated well with machining data, indicating the importance of high temperature stability with respect to the hot workpiece. Drawing on the experimental observations made during the project, the thesis concludes with suggestions for improving and optimising ceramic tool materials for turning purposes.

No description available.

The fully fashioned master’s thesis within the frame of the master’s study at the Fakulty of mechanical engineering deals with subject woodworking tools. There are characteristics of wood and tool materials used for woodworking. There is an emphasis on milling cutter in each case of construction of selected woodworking tools. Whereas there is concrete proposal of milling cutter used for production of half round profile – half round concave cutter – at the end of the thesis.

Master’s thesis are concerned with the cutting ceramic materials and its ef-fective usage. The first part of the thesis is focused on the general properties of the cutting ceramics, its history, development, production and description of the various types. This part includes as well a description of the mechanic-physical properties and the potential of the usage for machining. The second part of the work solves the general evaluation of the cutting power. The main issue in the next part is the identification of cutting ceramics range and the selection accor-ding to main world producers. The fourth part deals with the assessments and the comparison of the working conditions for different types of the machined ma-terials. The technical economic assessment shows the potentials in the total pro-duction costs reduction.

The diploma work deals with the evaluation of force load procedure problems when using reaming head MT3 depending on selected criteria of surface integrity of machined hole. It is possible to eliminate some unwanted elements when reaming by force load procedure analysis. These negative elements can influence both the tool e.g. its previous wear and the defect of a newly made hole.