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.

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.

MACHAČ Stanislav: Spherical rollers process innovation by applicaton of cold bulk forming. Diploma thesis of the attendance engineer´s studies, Institute of technology, 2nd year, 2nd level – summer term, study group 5O / 51, school year 2007 / 2008. FSI VUT Brno, department of forming and plastics, May 2008, 75 pages, 6 tables, 4 enclosures. The topic of this thesis is production innovation of spherical rollers for bearings. The innovation is based on the technology of cold bulk forming. According to the literary research and according to the current stage of production is proposed and conceived manufacturing process for cold upsetting instead of turning using in current spherical rollers production. This manufacturing process is dedicated for the bearing type 22226EJ. The production process is conceived with regard to determinate knuckle-joint press LLR 1000 (Smeral Brno, a.s.). Also with regard to determinate half-closed die upsetting and with regard to formability of the steel 100CrMn6. The proposal and check-up of tool functional parts are designed regarding the current setting of particular parts of the press. In the next part of this thesis the proposal of work-room layout dedicated for hand-filling of semi-factured product is conceived. In conclusion the comparison of spherical roller production budget between cold upsetting and turning is conceived.

The project elaborated in frame of engineering studies branch M-STG proposes a technology of connecting pin – structural steel 11 320 5R. The technological calculations were performed and the production procedure was devised on the basic on the literary study of cold bulk forming with concentration on the extrusion and upsetting. Forming machine was design HATEBUR BKA-3 with a nominal power 1800 kN. The component is made in four forming operations. Extruder will be made from tool steel 19 830, extrusion die from tool steel 19 830 and clamp ring from tool steel 19 740.

Le forgeage multi-matériaux est un procédé permettant la mise en forme et l’assemblage simultanés de matériaux différents. Ce procédé permet d’obtenir des pièces multi-matériaux avec le « bon matériau placé au bon endroit ». L’objectif des travaux de thèse est de définir les conditions nécessaires à l’établissement de la liaison métallurgique par forgeage à l’interface d’un couple d’aciers. Dans un premier temps, l’état de l’art a servi à l’identification les phénomènes physiques accompagnant le forgeage multi-matériaux et les paramètres clés pilotant l’établissement de la liaison métallurgique. Le principe de base de l’établissement d’une liaison passe par la fragmentation des oxydes en surface des matériaux et par l’application d’une pression de contact favorisant le contact entre les matériaux nus et la diffusion. Les deux paramètres clés identifiés sont donc la pression normale de contact et l’expansion de surface. Le protocole de caractérisation du co-forgeage mis en place comporte trois essais « simples » permettant de solliciter les interfaces avec des pressions et des expansions différentes. Ces dernières, estimées par simulation numérique de l’essai, sont mises en relation avec la qualité des liaisons obtenues évaluée, quant à elle, au travers d’observations métallographiques. Les premières simulations permettent de dimensionner les campagnes expérimentales. Celles-ci sont ensuite conduites sur les moyens de mise en forme de la plateforme VULCAIN. Les efforts de mise en forme et la géométrie globale des pièces et la répartition de matière servent de base à l’identification des paramètres de la simulation. La simulation ainsi obtenue et les observations métallographiques aux interfaces sont ensuite mises en lien. Cette démarche a permis de confirmer l’importance du rôle joué par la pression de contact et l’expansion de surface sur l’établissement d’une liaison au cours de la mise en forme du multi-matériaux. La répartition et la forme des particules d’oxydes semblent liées au chemin thermomécanique subi par l’interface. / The multi-material forging is a forming process allowing, simultaneously, the welding and shaping of multi-material parts with the right material at the right place. The purpose of the presented work is to identify the necessary conditions to obtain a metallurgical bond during forming between two different grades of steel. First, the state of the art allowed the identification of the physical phenomena occurring during multi-material forging and the determination of the key parameters of the bonding which are the contact pressure and the surface expansion at the both sides of the interface. The mechanisms to establish metallurgical bond by forging are based on the breaking and the dispersion of the oxide layer at the interface then the extrusion of the soft material through the voids generated between the oxide fragments. Second, the characterization methodology of this work is presented. It consists of three “simple” forming tests leading to different interface conditions (contact pressure and surface expansion). The first simulations allow the design of the experimental plan for each test. The comparison between simulations and experiments allows the identification of physical parameters of the simulation. Then, the contact pressure and the surface expansion of the identified simulations are used to analyze the metallographic structure and the bonding at the interface.The developed work confirms the major effect of the contact pressure and the surface expansion on the establishment of a metallurgical bond during multi-material forming. The size and the shape of the oxide particles seem to depend on the thermomechanical path at the interface.

This paper examines how the initial austenite grain size in quench and partitioning (Q-P) processes influences the final mechanical properties of Q-P steels. Differences in austenite grain size distribution may result, for example, from uneven heating rates of semi-finished products prior to a forging process. In order to quantify this influence, a carefully defined heat treatment of a cylindrical specimen made of the Q-P-capable 42SiCr steel was performed in a dilatometer. Different austenite grain sizes were adjusted by a pre-treatment before the actual Q-P process. The resulting mechanical properties were determined using the upsetting test and the corresponding microstructures were analyzed by scanning electron microscopy (SEM). These investigations show that a larger austenite grain size prior to Q-P processing leads to a slightly lower strength as well as to a coarser martensitic microstructure in the Q-P-treated material.

The project elaborated in a frame of Master‘s degree branch M-STG focuses on the design of a technology of sandwich coil used for connecting the aircraft floor sandwich panels to the fuselage bulkheads. The product is made of a lightweight aluminium alloy AlMn1. Combined cold extrusion with upsetting of the flange was chosen as the most fitting technology due to the manufacturing requirements and production series size of 120 000 pieces per year. The component is manufactured from a block blank in three operations by a progressive forming machine TPM 8-A with a nominal force of 1000 kN from Šmeral Brno a.s. producer. Within the project, tools for the production of the part were designed and also technical calculations for individual operations and technical and economic evaluation of production were made. The price of the component is estimated to be at least CZK 7,33.