Based on the concept of Process Signatures, the deep rolling process is analyzed, aiming at funct... more Based on the concept of Process Signatures, the deep rolling process is analyzed, aiming at functional relationships between material modifications and internal material loads during the process. The focus of this work is to investigate the influence of the workpiece temperature on the generated residual stress components. For this purpose, extensive finite element simulations of deep rolling were conducted, taking into account the effect of neighboring tool paths on the internal material loads and residual stress. A kinematic strain hardening model was parameterized and utilized and the simulations were validated experimentally. Simulated residual stresses agree qualitatively well with measurements and show a strong influence of the workpiece temperature as expected. Process Signature Components were generated, taking into account the maximal and minimal residual stress as well as their respective positions beneath the workpiece surface.
Spanende sowie umformende Fertigungsprozesse können durch die Aufprägung von mechanischen, thermi... more Spanende sowie umformende Fertigungsprozesse können durch die Aufprägung von mechanischen, thermischen oder auch chemischen Lasten (als separate oder kombinierte Last) den physikalischen und chemischen Zustand der Werkstückoberfläche sowie der Werkstückrandzone maßgeblich beeinflussen. Als Folge der Werkstoffbeanspruchung durch den Fertigungsprozess kann eine Veränderung der funktionsrelevanten Randzoneneigenschaften (z. B. Härte, Eigenspannungen, Gefüge) resultieren. Dieser Beitrag thematisiert das Potential von drei verschiedenen Fertigungsprozessen mit thermo-mechanischer Beanspruchung zur Steigerung der Randzonenintegrität. Diese Prozesse erzielen durch unterschiedliche Kombination mechanischer und thermischer Lasten Effekte der Kaltverfestigung und der Gefügeumwandlung in der Werkstückrandzone. Manufacturing processes such as machining or forming are causing mechanical, thermal or chemical loads within the workpiece which affect the physical and chemical properties of the surfa...
The development of novel structural materials with increasing mechanical requirements is a very r... more The development of novel structural materials with increasing mechanical requirements is a very resource-intense process if conventional methods are used. While there are high-throughput methods for the development of functional materials, this is not the case for structural materials. Their mechanical properties are determined by their microstructure, so that increased sample volumes are needed. Furthermore, new short-time characterization techniques are required for individual samples which do not necessarily measure the desired material properties, but descriptors which can later be mapped on material properties. While universal micro-hardness testing is being commonly used, it is limited in its capability to measure sample volumes which contain a characteristic microstructure. We propose to use alternative and fast deformation techniques for spherical micro-samples in combination with classical characterization techniques such as XRD, DSC or micro magnetic methods, which deliver...
A high-throughput method for the discovery of structural materials requires a large number of sam... more A high-throughput method for the discovery of structural materials requires a large number of samples with highly reproducible properties. We propose using spherical micro-samples, which can be quickly produced by molten metal single droplet processes with high geometrical reproducibility. However, geometrical reproducibility does not automatically yield in the reproducibility of specific properties that are governed by the microstructure and thermal history of the samples. This work evaluates the reproducibility of two different steels (AISI D3 and 5140) in their as-synthesized state without additional heat treatment. By determining a set of well-established high-throughput descriptors by electrochemical analysis, particle-oriented peening, and micro machining, we show that high reproducibility can be achieved. Additionally, the determined properties correlate well with their austenitic (AISI D3) and martensitic (AISI5140) state. The AISI D3 shows an improved corrosion resistance, ...
Spanende sowie umformende Fertigungsprozesse können durch die Aufprägung von mechanischen, thermi... more Spanende sowie umformende Fertigungsprozesse können durch die Aufprägung von mechanischen, thermischen oder auch chemischen Lasten (als separate oder kombinierte Last) den physikalischen und chemischen Zustand der Werkstückoberfläche sowie der Werkstückrandzone maßgeblich beeinflussen. Als Folge der Werkstoffbeanspruchung durch den Fertigungsprozess kann eine Veränderung der funktionsrelevanten Randzoneneigenschaften (z. B. Härte, Eigenspannungen, Gefüge) resultieren. Dieser Beitrag thematisiert das Potential von drei verschiedenen Fertigungsprozessen mit thermo-mechanischer Beanspruchung zur Steigerung der Randzonenintegrität. Diese Prozesse erzielen durch unterschiedliche Kombination mechanischer und thermischer Lasten Effekte der Kaltverfestigung und der Gefügeumwandlung in der Werkstückrandzone. Manufacturing processes such as machining or forming are causing mechanical, thermal or chemical loads within the workpiece which affect the physical and chemical properties of the surfa...
The productivity of grinding processes is often limited by the risk of thermal damage of the work... more The productivity of grinding processes is often limited by the risk of thermal damage of the workpiece surface layer. Therefore, the control of thermal conditions in the grinding arc is of utmost importance for both, industrial practice and academia. In order to optimize the application of the metal working fluid in grinding, devices and methodologies are needed which can assure the measurement of temperatures in grinding or within set-up mode and the control of demand-oriented fluid supply parameters (nozzle angle, nozzle height, nozzle outlet area, fluid jet velocity). The systematic use of such devices and methodologies for fluid supply optimization is enabling reliable and economic grinding processes.
Based on the concept of Process Signatures, the deep rolling process is analyzed, aiming at funct... more Based on the concept of Process Signatures, the deep rolling process is analyzed, aiming at functional relationships between material modifications and internal material loads during the process. The focus of this work is to investigate the influence of the workpiece temperature on the generated residual stress components. For this purpose, extensive finite element simulations of deep rolling were conducted, taking into account the effect of neighboring tool paths on the internal material loads and residual stress. A kinematic strain hardening model was parameterized and utilized and the simulations were validated experimentally. Simulated residual stresses agree qualitatively well with measurements and show a strong influence of the workpiece temperature as expected. Process Signature Components were generated, taking into account the maximal and minimal residual stress as well as their respective positions beneath the workpiece surface.
Spanende sowie umformende Fertigungsprozesse können durch die Aufprägung von mechanischen, thermi... more Spanende sowie umformende Fertigungsprozesse können durch die Aufprägung von mechanischen, thermischen oder auch chemischen Lasten (als separate oder kombinierte Last) den physikalischen und chemischen Zustand der Werkstückoberfläche sowie der Werkstückrandzone maßgeblich beeinflussen. Als Folge der Werkstoffbeanspruchung durch den Fertigungsprozess kann eine Veränderung der funktionsrelevanten Randzoneneigenschaften (z. B. Härte, Eigenspannungen, Gefüge) resultieren. Dieser Beitrag thematisiert das Potential von drei verschiedenen Fertigungsprozessen mit thermo-mechanischer Beanspruchung zur Steigerung der Randzonenintegrität. Diese Prozesse erzielen durch unterschiedliche Kombination mechanischer und thermischer Lasten Effekte der Kaltverfestigung und der Gefügeumwandlung in der Werkstückrandzone. Manufacturing processes such as machining or forming are causing mechanical, thermal or chemical loads within the workpiece which affect the physical and chemical properties of the surfa...
The development of novel structural materials with increasing mechanical requirements is a very r... more The development of novel structural materials with increasing mechanical requirements is a very resource-intense process if conventional methods are used. While there are high-throughput methods for the development of functional materials, this is not the case for structural materials. Their mechanical properties are determined by their microstructure, so that increased sample volumes are needed. Furthermore, new short-time characterization techniques are required for individual samples which do not necessarily measure the desired material properties, but descriptors which can later be mapped on material properties. While universal micro-hardness testing is being commonly used, it is limited in its capability to measure sample volumes which contain a characteristic microstructure. We propose to use alternative and fast deformation techniques for spherical micro-samples in combination with classical characterization techniques such as XRD, DSC or micro magnetic methods, which deliver...
A high-throughput method for the discovery of structural materials requires a large number of sam... more A high-throughput method for the discovery of structural materials requires a large number of samples with highly reproducible properties. We propose using spherical micro-samples, which can be quickly produced by molten metal single droplet processes with high geometrical reproducibility. However, geometrical reproducibility does not automatically yield in the reproducibility of specific properties that are governed by the microstructure and thermal history of the samples. This work evaluates the reproducibility of two different steels (AISI D3 and 5140) in their as-synthesized state without additional heat treatment. By determining a set of well-established high-throughput descriptors by electrochemical analysis, particle-oriented peening, and micro machining, we show that high reproducibility can be achieved. Additionally, the determined properties correlate well with their austenitic (AISI D3) and martensitic (AISI5140) state. The AISI D3 shows an improved corrosion resistance, ...
Spanende sowie umformende Fertigungsprozesse können durch die Aufprägung von mechanischen, thermi... more Spanende sowie umformende Fertigungsprozesse können durch die Aufprägung von mechanischen, thermischen oder auch chemischen Lasten (als separate oder kombinierte Last) den physikalischen und chemischen Zustand der Werkstückoberfläche sowie der Werkstückrandzone maßgeblich beeinflussen. Als Folge der Werkstoffbeanspruchung durch den Fertigungsprozess kann eine Veränderung der funktionsrelevanten Randzoneneigenschaften (z. B. Härte, Eigenspannungen, Gefüge) resultieren. Dieser Beitrag thematisiert das Potential von drei verschiedenen Fertigungsprozessen mit thermo-mechanischer Beanspruchung zur Steigerung der Randzonenintegrität. Diese Prozesse erzielen durch unterschiedliche Kombination mechanischer und thermischer Lasten Effekte der Kaltverfestigung und der Gefügeumwandlung in der Werkstückrandzone. Manufacturing processes such as machining or forming are causing mechanical, thermal or chemical loads within the workpiece which affect the physical and chemical properties of the surfa...
The productivity of grinding processes is often limited by the risk of thermal damage of the work... more The productivity of grinding processes is often limited by the risk of thermal damage of the workpiece surface layer. Therefore, the control of thermal conditions in the grinding arc is of utmost importance for both, industrial practice and academia. In order to optimize the application of the metal working fluid in grinding, devices and methodologies are needed which can assure the measurement of temperatures in grinding or within set-up mode and the control of demand-oriented fluid supply parameters (nozzle angle, nozzle height, nozzle outlet area, fluid jet velocity). The systematic use of such devices and methodologies for fluid supply optimization is enabling reliable and economic grinding processes.
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