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Item type:Project, Access status: without files , Investigations on temperature-activated coatings for friction reduction during turning of titanium alloysThe application of high performance titanium alloys enables great advancement in many sectors of the industry. These materials offer good mechanical, thermal and chemical properties. Application areas of the most widely used titanium alloy TiAl6V4 are in medical technology (implants) in the automotive sector (connecting rods, valves, turbocharger), in the plastic industry (nozzles for injection), in the chemical industry (stirring elements, valves), in power engineering (turbine blades) and in the aerospace industry (engine and suspension parts). The outstanding properties of this material difficult but at the same time its machining. Compared to steel materials, TiAl6V4 exhibits a high temperature resistance up to T = 550 ° C and low thermal conductivity (λ = 5.8 W/mK) as well as a pronounced tendency to strain hardening and an abrasive effect. The poor thermal conductivity leads to high chip temperatures und the process heat flows for the most part in the tools and is not transported through the chip. Another consequence is the development of chemical reactions at the tool surface due to the high process temperature. For the machining of these materials, this means that the tools are subject to a considerable thermal stress and a high mechanical load. Therefore, the production of complex components made of titanium alloys by cutting process is economically not possible due to the fact that this material causes high tool wear, which is associated with high costs. The use of hard coatings deposited by PVD (physical vapour deposition) process for tuning of titanium alloys are not established in the industry. The reason for this is that the corresponding load collective is so far insufficiently researched and the chemical and physical cause-effect relations between titanium and coated tools are not yet understood. The aim of this cooperation research project between IOT and IPMT is the production of temperature active (Cr,Al,V)N coating systems by a combination of dcMS (direct current magnetron sputtering) and HPPMS (high power pulsed magnetron sputtering) technology as well as the investigation of physical and chemical cause-effect relations between coatings and TiAl6V4 and the description of the thermal and mechanical loads during turning of titanium alloy with coated cemented carbide tools. The results of this research project will contribute to make an economical cutting process for titanium alloys possible.65 - Some of the metrics are blocked by yourconsent settings
Item type:Project, Access status: without files , Process-independent force and surface model for oblique cutting of fiber reinforced polymersFiber reinforced polymers are often used in lightweight design. Due to the orthotropic material properties, the cutting mechanisms during chip removal differ significantly from those of isotropic materials. So far, the fundamental mechanisms have been investigated primarily for orthogonal cutting. However, oblique cutting is generally present in industrial practice, in which a three-dimensional cutting process occurs due to the spatial engagement conditions of the tool’s cutting edges. The spatial engagement conditions result from a combination of the 3D spatial orientation of the cutting edge and the cutting direction with respect to the fiber.Preliminary studies reveal a significant influence of the 3D spatial cutter-fiber-orientation on the cutting forces and the resulting cutting surface. The surface integrity can affect the mechanical behavior of lightweight structures under static and dynamic loads. In particular, occurring fiber pull-out is critical for the surface integrity. The objective of the project is a cutting force and surface model for the machining of fiber reinforced polymers with particular consideration of oblique cutting. The prediction of cutting forces is based on a semi-empirical model, which has a process-independent validity. The model will be transferred to milling. Furthermore a transfer to drilling out and countersinking is envisaged in a second project phase. Innovative experimental setups enable efficient and comprehensive identification of cutting force coefficients for the first time, also under high cutting speed as well as arbitrary orientation of the cutter and cutting direction relative to the fiber. The surface model is developed from the correlation between the spatial load situation and the measured surface condition. It allows the prediction of critical cutting conditions with respect to surface quality, in particular fiber pull-out. The rotation-angle-dependent simulation of the process forces and the cutting surfaces allows conclusions to be drawn about the process-specific mechanisms in terms of 3D spatial engagement conditions, which has not been possible up to now because of the focus on orthogonal cutting. Compared to the mere mechanistic force modelling by calibration in a drilling or milling process, the semi-empirical model shows the load distribution along the cutting edge. This enables the analysis of phenomena which are only affecting a small region of the cutter and shows optimization potential in terms of surface quality.49 - Some of the metrics are blocked by yourconsent settings
Item type:Project, Access status: without files , Machining-induced temperature field in CFRP materials (TFC)Due to their remarkable specific strength and stiffness, carbon fiber reinforced plastics (CFRP) are increasingly used for highly loaded lightweight structures, e.g. in the aerospace industry. By suitable arrangement of unidirectional (UD) fiber layers, the fibers can be optimally adapted to the effective load directions. After the original near-net forming process, it is usually necessary to machine the components to meet the precision requirements. Often, milling is used for this step. Workpiece loads associated with machining carry the risk of damaging the functional surfaces mechanically and thermally which may lead to high costs due to repair or scrap.The heat generated during machining, its distribution within the part and the resulting thermal damage are, amongst other factors, dependent on the fiber orientation with respect to the feed direction. In preliminary research, an analytical model for the calculation of the temperature field within orthotropic workpieces for arbitrary fiber orientations was developed. In this model, the (effective) heat source width and the heat flux are of primary importance. Currently, those parameters are difficult to assess, but could be identified for exemplary individual cases from experiments in this research.The objective of this research proposal is to fundamentally investigate the dependence of the thermal process parameters heat source width and heat flux on tool and material properties as well as on the cutting conditions. For this purpose, the existing machining center for cutting of CFRP is enhanced with the necessary measuring equipment for thermomechanical process characterization. Based on experimentally identified features, empirical correlations are deduced and described by a comprehensive model. Thus, the model-based simulation of the temperature field and thermal damage in the heat-affected zone of UD-CFRP workpieces is established as a function of the relevant input parameters.The model established for UD-CFRP is empirically expanded within this project and thereby delivers scientifically relevant findings on cause-effect relationships of thermal damages in machining. It is expected to be of high value for industrial practice, as the model-based simulation of UD-CFRP systems reveals process limits when machining CFRP made of non-crimped fabrics (NCF). The portability to NCF-CFRP as well as the implementation of neglected effects, e.g. the heat transfer at the part surface, will be further investigated in the second funding phase.56 - Some of the metrics are blocked by yourconsent settings
Item type:Project, Access status: without files , 32 - Some of the metrics are blocked by yourconsent settings
Item type:Project, Access status: with files , Sektionsmontage und SysteminstallationDas Verbundprojekt Sektionsmontage und Systeme (SeMoSys) hat die Zielsetzung, die weitgehend automatisierte Sektionsmontage mit partieller Systeminstallation zu entwickeln. Innovative Flugzeug-Architektur und Bauweise sollen mit einem Neuprogramm umgesetzt werden. Die integrierende Betrachtung von Struktur und System bietet sowohl im Herstellprozess als auch im Engineering Potentiale für die leistungsfähige und effiziente Luftfahrt. Innovation ist die gesamtheitliche Konzeption und Validierung. Es sollen Montageaufwände um 20% und Durchlaufzeiten um 15% reduziert werden. Die Entwicklungsstränge von SeMoSys beinhalten: 1) Die automatisierte Sektionsmontage mit Systeminstallation mit den Aspekten der Digitalisierung, Mensch-Maschine Interaktion, Ergonomie mit der Wirtschaftlichkeitsbetrachtung. 2) Die interferierende Bauweise mit innovativen Design- und Architekturkonzepten, die ATA-übergreifende Betrachtung, Anbindungskonzepte und Toleranzen. 3) Die methodische, vergleichende Betrachtung Aerostructure/ non Aerostructure mit einer bottom up Analyse. den Aspekten und Chancen durch Modularität.113 20 - Some of the metrics are blocked by yourconsent settings
Item type:Project, Access status: without files , 41 - Some of the metrics are blocked by yourconsent settings
Item type:Project, Access status: with files , 104 20 - Some of the metrics are blocked by yourconsent settings
Item type:Project, Access status: without files , 127 - Some of the metrics are blocked by yourconsent settings
Item type:Project, Access status: without files , Investigations on temperature-activated coatings for friction reduction during turning of titanium alloysThe application of high performance titanium alloys enables great advancement in many sectors of the industry. These materials offer good mechanical, thermal and chemical properties. Application areas of the most widely used titanium alloy TiAl6V4 are in medical technology (implants) in the automotive sector (connecting rods, valves, turbocharger), in the plastic industry (nozzles for injection), in the chemical industry (stirring elements, valves), in power engineering (turbine blades) and in the aerospace industry (engine and suspension parts). The outstanding properties of this material difficult but at the same time its machining. Compared to steel materials, TiAl6V4 exhibits a high temperature resistance up to T = 550 ° C and low thermal conductivity (λ = 5.8 W/mK) as well as a pronounced tendency to strain hardening and an abrasive effect. The poor thermal conductivity leads to high chip temperatures und the process heat flows for the most part in the tools and is not transported through the chip. Another consequence is the development of chemical reactions at the tool surface due to the high process temperature. For the machining of these materials, this means that the tools are subject to a considerable thermal stress and a high mechanical load. Therefore, the production of complex components made of titanium alloys by cutting process is economically not possible due to the fact that this material causes high tool wear, which is associated with high costs. The use of hard coatings deposited by PVD (physical vapour deposition) process for tuning of titanium alloys are not established in the industry. The reason for this is that the corresponding load collective is so far insufficiently researched and the chemical and physical cause-effect relations between titanium and coated tools are not yet understood. The aim of this cooperation research project between IOT and IPMT is the production of temperature active (Cr,Al,V)N coating systems by a combination of dcMS (direct current magnetron sputtering) and HPPMS (high power pulsed magnetron sputtering) technology as well as the investigation of physical and chemical cause-effect relations between coatings and TiAl6V4 and the description of the thermal and mechanical loads during turning of titanium alloy with coated cemented carbide tools. The results of this research project will contribute to make an economical cutting process for titanium alloys possible.109