J. Funct. Biomater. 2015, 6 193 Abstract: Thermosensitive injectable hydrogels based on chitosan ... more J. Funct. Biomater. 2015, 6 193 Abstract: Thermosensitive injectable hydrogels based on chitosan neutralized with sodium beta-glycerophosphate (Na-β-GP) have been studied as biomaterials for drug delivery and tissue regeneration. Magnesium (Mg) has been reported to stimulate adhesion and proliferation of bone forming cells. With the aim of improving the suitability of the aforementioned
The effect of ultra-fast heating on the microstructures of steel has been thoroughly studied over... more The effect of ultra-fast heating on the microstructures of steel has been thoroughly studied over the last year as it imposes a suitable alternative for the production of ultra high strength steel grades. Rapid reheating followed by quenching leads to fine-grained mixed microstructures. This way the desirable strength/ductility ratio can be achieved while the use of costly alloying elements is significantly reduced. The current work focuses on the effect of ultra-fast heating on commercial dual phase grades for use in the automotive industry. Here, a cold-rolled, low-carbon, medium-manganese steel was treated with a rapid heating rate of 780 °C/s to an intercritical peak temperature (760 °C), followed by subsequent quenching. For comparison, a conventionally heated sample was studied with a heating rate of 10 °C/s. The initial microstructure of both sets of samples consisted of ferrite, pearlite and martensite. It is found that the very short heating time impedes the dissolution of ...
Clear structure-performance correlation for the dry reforming of methane – spray drying for excel... more Clear structure-performance correlation for the dry reforming of methane – spray drying for excellent sintering and cocking resistivity.
Seven factors in catalyst development were selected and rated towards their impact on methanation... more Seven factors in catalyst development were selected and rated towards their impact on methanation as a downstream process.
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, Oct 1, 2021
Abstract The microstructure and mechanical properties of an Fe-0.24C-1.4Mn-1.4Si steel were inves... more Abstract The microstructure and mechanical properties of an Fe-0.24C-1.4Mn-1.4Si steel were investigated after combining ultrafast heating (UFH) at a heating rate of 500 °C/s followed by fast cooling to room temperature (DQ) or quenching and partitioning processes (Q&P). Two peak temperatures were studied, annealing into the intercritical range and above the AC3 temperature. After ultrafast heating and quenching, the resulting microstructures revealed that intercritical annealing led to the formation of a banded ferritic-martensitic microstructure. On the other hand, heating above the intercritical range led to an even distribution of allotriomorphic ferrite grains upon fast cooling and a complex phase microstructure, consisting mainly of martensite, was produced. Q&P steel grades exhibit an enhanced mechanical behavior compared to their DQ counterparts, where yield strength, uniform elongation, and total elongation increased after partitioning at 400 °C. The ultimate tensile strength of the Q&P steels decreased compared to the DQ steels annealed at the same peak temperature. However, the final strength-ductility balance of the studied Q&P steels was superior to the DQ steel grades. Moreover, considerable strength and improved ductility were obtained through the combination of peak annealing above the AC3 temperature followed by Q&P. These results are attributed to an interplay between a sustainable TRIP effect and effective strain-stress partitioning among the microconstituents resulted after the Q&P process.
ABSTRACT A 1C3Mn1.5Si steel was partially transformed into martensite by quenching to room temper... more ABSTRACT A 1C3Mn1.5Si steel was partially transformed into martensite by quenching to room temperature after full austenitisation. A partitioning treatment was applied in situ in a high resolution transmission electron microscope. The width of an austenite grain in between martensite constituents was followed as a function of the annealing time. Migration of the martensite–austenite interfaces was quantitatively measured and compared with results from a model for carbon partitioning from martensite to austenite involving interface motion. The kinetics of the observed movement suggests that the interface has a semi-coherent nature. This work shows that grain boundary mobility of the martensite–austenite interfaces during annealing may play an important role in the microstructure development during the process of Quenching and Partitioning in steels.
J. Funct. Biomater. 2015, 6 193 Abstract: Thermosensitive injectable hydrogels based on chitosan ... more J. Funct. Biomater. 2015, 6 193 Abstract: Thermosensitive injectable hydrogels based on chitosan neutralized with sodium beta-glycerophosphate (Na-β-GP) have been studied as biomaterials for drug delivery and tissue regeneration. Magnesium (Mg) has been reported to stimulate adhesion and proliferation of bone forming cells. With the aim of improving the suitability of the aforementioned
The effect of ultra-fast heating on the microstructures of steel has been thoroughly studied over... more The effect of ultra-fast heating on the microstructures of steel has been thoroughly studied over the last year as it imposes a suitable alternative for the production of ultra high strength steel grades. Rapid reheating followed by quenching leads to fine-grained mixed microstructures. This way the desirable strength/ductility ratio can be achieved while the use of costly alloying elements is significantly reduced. The current work focuses on the effect of ultra-fast heating on commercial dual phase grades for use in the automotive industry. Here, a cold-rolled, low-carbon, medium-manganese steel was treated with a rapid heating rate of 780 °C/s to an intercritical peak temperature (760 °C), followed by subsequent quenching. For comparison, a conventionally heated sample was studied with a heating rate of 10 °C/s. The initial microstructure of both sets of samples consisted of ferrite, pearlite and martensite. It is found that the very short heating time impedes the dissolution of ...
Clear structure-performance correlation for the dry reforming of methane – spray drying for excel... more Clear structure-performance correlation for the dry reforming of methane – spray drying for excellent sintering and cocking resistivity.
Seven factors in catalyst development were selected and rated towards their impact on methanation... more Seven factors in catalyst development were selected and rated towards their impact on methanation as a downstream process.
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, Oct 1, 2021
Abstract The microstructure and mechanical properties of an Fe-0.24C-1.4Mn-1.4Si steel were inves... more Abstract The microstructure and mechanical properties of an Fe-0.24C-1.4Mn-1.4Si steel were investigated after combining ultrafast heating (UFH) at a heating rate of 500 °C/s followed by fast cooling to room temperature (DQ) or quenching and partitioning processes (Q&P). Two peak temperatures were studied, annealing into the intercritical range and above the AC3 temperature. After ultrafast heating and quenching, the resulting microstructures revealed that intercritical annealing led to the formation of a banded ferritic-martensitic microstructure. On the other hand, heating above the intercritical range led to an even distribution of allotriomorphic ferrite grains upon fast cooling and a complex phase microstructure, consisting mainly of martensite, was produced. Q&P steel grades exhibit an enhanced mechanical behavior compared to their DQ counterparts, where yield strength, uniform elongation, and total elongation increased after partitioning at 400 °C. The ultimate tensile strength of the Q&P steels decreased compared to the DQ steels annealed at the same peak temperature. However, the final strength-ductility balance of the studied Q&P steels was superior to the DQ steel grades. Moreover, considerable strength and improved ductility were obtained through the combination of peak annealing above the AC3 temperature followed by Q&P. These results are attributed to an interplay between a sustainable TRIP effect and effective strain-stress partitioning among the microconstituents resulted after the Q&P process.
ABSTRACT A 1C3Mn1.5Si steel was partially transformed into martensite by quenching to room temper... more ABSTRACT A 1C3Mn1.5Si steel was partially transformed into martensite by quenching to room temperature after full austenitisation. A partitioning treatment was applied in situ in a high resolution transmission electron microscope. The width of an austenite grain in between martensite constituents was followed as a function of the annealing time. Migration of the martensite–austenite interfaces was quantitatively measured and compared with results from a model for carbon partitioning from martensite to austenite involving interface motion. The kinetics of the observed movement suggests that the interface has a semi-coherent nature. This work shows that grain boundary mobility of the martensite–austenite interfaces during annealing may play an important role in the microstructure development during the process of Quenching and Partitioning in steels.
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