A5023548578- Microstructure and Mechanical Properties of Steels
- Metal Alloys Wear and Properties
- Metal and Thin Film Mechanics
- Metallurgy and Material Forming
- Advanced machining processes and optimization
- Advanced Surface Polishing Techniques
- Welding Techniques and Residual Stresses
- Magnetic Properties and Applications
- Metal Forming Simulation Techniques
- Advanced Machining and Optimization Techniques
- High Entropy Alloys Studies
- Non-Destructive Testing Techniques
- Surface Treatment and Residual Stress
- Additive Manufacturing Materials and Processes
- Metallurgical Processes and Thermodynamics
- Advanced materials and composites
- Microstructure and mechanical properties
- Aluminum Alloys Composites Properties
- Advanced Materials Characterization Techniques
- Tribology and Wear Analysis
- Thermography and Photoacoustic Techniques
- Electron and X-Ray Spectroscopy Techniques
- Advanced Sensor Technologies Research
- Corrosion Behavior and Inhibition
- Calibration and Measurement Techniques
Leibniz-Institut für Werkstofforientierte Technologien - IWT
2016-2025
University of Bremen
2016-2025
Staats- und Universitätsbibliothek Bremen
2018-2023
Walter de Gruyter (Germany)
2020-2022
Forschungsgemeinschaft Werkzeuge und Werkstoffe
2022
Deutsche Post (Germany)
2015
National Institute of Standards and Technology
1979
Additive manufacturing (AM) processing of tool steels has a high level complexity due to the martensitic transformation and consequently tempering during component manufacturing. The thermal history generated over part is very complex challenging evaluate after AM process. By using energy synchrotron X-ray diffraction (HEXRD), this work performs series in situ laser-directed deposition (L-DED) experiments reveal phase lattice defect evolution at different parts printed thin wall made...
Abstract After grinding of hardened workpieces, especially in case safety-relevant components, usually non-destructive testing is carried out to detect thermo-mechanical damages the surface layer. In-process detection methods allow a fast reaction negative changes before producing large amount rejects and open possibility save additional time for post-process inspection. However, these are not industrially used yet, since boundary conditions application limits defined so far. This study...
Abstract New processing routes and alternatives have been studied in the manufacture of automotive parts aiming for lower energy consumption less environmental impact. In this context, continuous cooling bainitic steels emerged to address demand by eliminating quenching tempering treatments. substitution heat treatments improve wear resistance on surface, plasma nitriding is a candidate. However, effects core microstructures over long time processes at subcritical temperatures are limited...
Abstract Low-pressure carburizing (LPC) is a recipe-controlled heat treatment process for surface layer hardening. The combination of the parameters determines chemical gradients established within case, local microstructure and depth distribution resulting process-induced residual stresses. Here, objective was to quantify influence on material state case hardening steel AISI 5120 (EN 20MnCr5). Therefore, quenching processes were examined using self-built chamber specially designed in situ...
The surface and subsurface conditions of components are significant for their functional properties. Every manufacturing process step changes the condition due to its mechanical, chemical and/or thermal impact. depth affected zone varies different machining operations, is predetermined by parameters characteristics. Furthermore, initial state has a decisive influence on interactions that lead final conditions. aim investigation presented here compare load characteristics over applied...
Despite a growing interest in additive manufacturing technologies, there is still limited selection of suitable materials developed regarding the unique non-equilibrium cooling conditions. A highly promising alloy system for Laser Powder Bed Fusion (LPBF) Al-Ce, which shows outstanding processability recent studies. The medium strengths already achievable with binary are to be improved these investigations by additional precipitation-forming elements. By adding Mg and Si, very high tensile...
Thermomechanical processing of low carbon bainitic steels is used to obtain a microstructure with good strength and toughness by continuous cooling after forging without the need further heat treating, hence reducing manufacturing costs. However, hot parameters can significantly influence in forged material. A series treating experiments was carried out analyze effect austenitizing time temperature on grain growth Prior Austenite Grain Size (PAGS) continuously cooled microstructure. The...
Non-destructive determination of workpiece properties after heat treatment is great interest in the context quality control production but also for prevention damage subsequent grinding process. Micromagnetic methods offer good possibilities, must first be calibrated with reference analyses on known states. This work compares accuracy and reliability different calibration non-destructive evaluation carburizing depth surface hardness carburized steel. Linear regression analysis used...
This paper discusses results acquired during surface grinding experiments performed on hardened steel workpieces. The experimental show different zones of thermally induced material modifications depending the contact time Δt and maximum zone temperature Tmax. In particular it was observed that rehardened occurred within two separated ranges temperatures times. Further analyses revealed these correspond to significantly mechanical loads as well varying retained austenite rates. shall help...
Infeed rotary swaging is a cold forming production technique to reduce the diameter of axisymmetric components. The achieved discontinuously by series radial strokes that are spread over shell part. Due tolerances within machine, these perform individually and resulting stroke pattern not homogeneous with regards circumferential longitudinal distribution. Nevertheless, in combination high number performed large contact area between dies part, external part properties, such as diameter,...
The development of novel structural materials with increasing mechanical requirements is a very resource-intense process if conventional methods are used. While there high-throughput for the functional materials, this not case materials. Their properties determined by their microstructure, so that increased sample volumes needed. Furthermore, new short-time characterization techniques required individual samples which do necessarily measure desired material properties, but descriptors can...
Martensitic steels are tempered to increase the toughness of metastable martensite, which is brittle in as-quenched state, and achieve a more stable microstructure. During tempering steels, several particular overlapping effects can arise. Classical dilatometric investigations only detect by monitoring integral length change sample. Additional in-situ diffractometry allowed differentiation individual such as transformation retained austenite formation cementite during tempering....
Abstract Grinding processes are often the last step in value-added chain of high-performance hardened steel components. However, thermo-mechanical loads which can take place during process have a detrimental effect on surface integrity ground parts, generally tested by post-process measurements. In present study, two different approaches for an in-process inspection workpiece were assessed using magnetic Barkhausen noise analysis cylindrical grinding workpieces. The results showed that both...