This thesis deals with tests of forming operations, which are used to determine coefficient of friction. In the theoretical part of thesis, the individual tests are described in details, with the greatest emphasis on the upsetting test. In the experimental part of thesis was perform upsetting test on the cylindrical and ring samples. Coefficient of friction of the cylindrical samples was determined by a calculation method and ring samples were evaluated using diagram of calibration. The thesis includes comparison of the result received on lubricant and unlubricated samples and method for determined coefficient of friction. Graphite Delta 144 was used as a lubricant. This result show that the lubricant has a positive effect on forming process.

The thesis deals with the design of a suitable technology for serial production of a pin. The component material is structural steel 11,320 5R. Due to the series production and material savings, the molding technology was chosen to be cold. For production, the CM 4-5 ECO HATEBUR process press was designed with a nominal force of 1 700 kN. Progressive tool and drawing documentation of tools for the final operation were also designed. The tool load was verified by manual calculation, and the finite element method was calculated to heat the formed blank due to molding.

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The aim of this diploma thesis is to design valve production line for combustion engines by volume forming with heat. The production of line will be 2 500 000-10 000 000 pieces per year. In the introduction of this thesis are described production technologies. Next part is about design of production lines and description of each machine for each technology. Then are made the basic calculations for designe for each machine.

The aim of this diploma thesis is to design valve production line for combustion engines by volume forming with heat. The production of line will be 2 500 000-10 000 000 pieces per year. In the introduction of this thesis are described production technologies. Next part is about design of production lines and description of each machine for each technology. Then are made the basic calculations for designe for each machine.

This thesis deals with a proposal of a technology for manufacturing a carrier pin made of corrosion resistant chrome steel 17 021.3. Having studied the information about cold bulk-metal forming in the available literature, I have suggested two variants of manufacturing processes. The suggested manufacturing variants consist of four forming operations which combine upsetting and extrusion. As far as the chosen variant is concerned, there have been made technological and strength calculations for the individual operations. As regards the designed technology, I have opted for the automatic multistation forming machine TPZK 25, produced by the company ŠMERAL Brno.

Diploma thesis focus on the proposal of the carrier pin production from the steel 17 021 by cold bulk forming technology with sight on the upsetting and extrusion. There were suggested two versions of the technological plan from which was one chosen as optimal. There were carried out calculation of deformation, forming and deformation resistances and forming forces for the chosen version. Machine for the part TPM 12 production was chosen on the basis of the global forming force 660 kN. Furthermore there were proposed forming tools for the second operation – feed forward extrusion. Finally there was made technical and economical evaluation.

<p>Predstavljena je nova metoda intenzivne plastične deformacije &ndash; višefazno sabijanje V-alatom. Koristeći ovu metodu, sabijanjem u osamnaest faza, unapređene su mehaničke osobine niskougljeničnog čelika Č.1221 &ndash; tvrdoća, čvrstoća i deformabilnost. Za ispitivanje mikrostrukture korišćeni su svetlosni, skening i transmisioni mikroskop. Prosečna veličina kristalnog zrna početnog materijala od 19 mikrometara je smanjena na 250 nanometara nakon dvanaest faza sabijanja. Nakon osamnaest faza sabijanja na čelu uzorka ostvarena je ukupna deformacija u iznosu od 3,38.</p> / <p>A new severe plastic deformation method has been presented - multistage upsetting by V-shape dies. By using this method, in eighteen upsetting stages, mechanical propreties (hardness, strenght and formability) of C15E low carbon steel has been improved. For microstructure analysis light, scanning and transmission microscopes have been employed. Initial average grain size of 19 &mu;m has been reduced to 250 nm after twelve upsetting stages. After eighteen upsetting stages, total effective deformation at the sample forehead of 3,38 has been obtained.</p>

Producing axi-symmetrical parts with holes from tubular stock by tube upsetting is a frequently used technique in industry. There are basically four types of tube upsetting process / external, internal, simultaneous internal and external upsetting, and expanding of tube. In general, tubular parts require more than one upsetting stage. In industry, generally trial-error methods, which require lots of time and effort depending on experience, are used for the design of stages. Wrong design causes failures during production. On the other hand, the problems, which are likely to be encountered in manufacturing, can be observed and solved in the design stage by using finite element analysis. In this study, the finite element analyses of external, internal, simultaneous internal and external tube upsetting, and tube expanding processes have been realized. During the analyses, the part and the die geometries at the intermediate stages, which have been designed according to the proposed procedures, have been used. The stress and strain distributions and die filling actions have been observed during the process. The process design and die geometries have been evaluated according to the finite element results. It has been seen that the recommended procedures generally generate acceptable designs. In some cases, it has been noted that minor modifications may be required on the design.

O presente trabalho apresenta um breve apanhado do processo de forjamento, resultados da investigação experimental e da análise computacional acerca do teste de compressão do anel e ensaio do tubo cônico, ambos visando a determinação do coeficiente de atrito existente na região de contato entre as matrizes e os corpos-de-prova, para as ligas de alumínio AA6351 e de titânio Ti6Al4V. Foram realizadas curvas teóricas de calibração do coeficiente de atrito tanto para o alumínio quanto para o titânio com faixa de temperatura distinta para cada um dos materiais. Após a realização da calibração por meio das curvas foram realizados os ensaios práticos de compressão do anel e do tubo cônico, também foram realizadas as simulações computacionais dos ensaios do tubo. Estas simulações permitiram a verificação teórica do fluxo de material no interior dos corpos de prova comparando-as com o material obtido em ensaios práticos, comprovando a eficiência dos programas de simulação, visto que a geometria do tubo favorece a comparação entre a simulação e os testes experimentais. Os resultados obtidos tanto nos experimentos teóricos como os práticos, efetuou-se uma comparação com os dados das referências bibliográficas descritas neste trabalho. Em que os dois lubrificantes testados apresentaram desempenho satisfatório, devido à redução do contato interfacial da relação matriz/peça. E o ensaio do tubo cônico mostrou-se viável apenas para determinação a quente do coeficiente de atrito, neste caso o comportamento em ambos os ensaios é similar. / This paper presents a brief overview of the forging process and the results of experimental investigation and computational analysis of ring compression testing and conical tube-upsetting test, both aiming to determine the coefficient of friction in the region of contact between die and bodies-of-evidence for the AA6351 aluminum alloy and titanium Ti6Al4V. Theoretical calibration through curves were performed of the coefficient of friction were performed for both aluminum and titanium with different temperature range for each material. After completion of the calibration curves compression ring and the conical tube practical tests were performed, computer simulations of the tube-upsetting test were also performed. Continue) These simulations allowed to verify the theoretical flow of material within the samples and comparing them with the material obtained in practical tests, proving the efficiency of simulation programs, since the geometry of the tube facilitates the comparison between the simulation and testing experiments. The results in both theoretical and practical experiments, were a compared with the data from the references described herein. Two oils tested showed a satisfactory performance due to the reduced interfacial contact relationship die/workpiece. And the tube-upsetting test was feasible only to determine the hot coefficient of friction, in this case the behavior in both tests is similar.