The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Mark A Gibson - One of the best experts on this subject based on the ideXlab platform.
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age hardening in die cast mg al re alloys due to minor mn additions
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2016Co-Authors: Trevor B Abbott, Mark A Gibson, Mark Alan EastonAbstract:Abstract Die-cast Mg–Al–rare earth (RE) alloys are normally used in the as-cast condition without the application of heat treatment because it is a common perception that heat treatment will not provide benefit to these alloys. This paper reports, for the first time, that enhanced age Hardenability can be achieved in die-cast Mg–Al–RE alloys with minor Mn additions. For example, the yield strength of Mg–4 wt%Al–3 wt%La alloy with 0.32 wt% Mn is increased by ∼34 MPa (∼26%) after ageing at 200 °C for 32 h (T5). The enhanced age Hardenability is associated with the precipitation of nanoscale Al–Mn particles during ageing.
Trevor B Abbott - One of the best experts on this subject based on the ideXlab platform.
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age hardening in die cast mg al re alloys due to minor mn additions
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2016Co-Authors: Trevor B Abbott, Mark A Gibson, Mark Alan EastonAbstract:Abstract Die-cast Mg–Al–rare earth (RE) alloys are normally used in the as-cast condition without the application of heat treatment because it is a common perception that heat treatment will not provide benefit to these alloys. This paper reports, for the first time, that enhanced age Hardenability can be achieved in die-cast Mg–Al–RE alloys with minor Mn additions. For example, the yield strength of Mg–4 wt%Al–3 wt%La alloy with 0.32 wt% Mn is increased by ∼34 MPa (∼26%) after ageing at 200 °C for 32 h (T5). The enhanced age Hardenability is associated with the precipitation of nanoscale Al–Mn particles during ageing.
Y He - One of the best experts on this subject based on the ideXlab platform.
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dissolution and precipitation behaviors of boron bearing phase and their effects on Hardenability and toughness of 25crmonbb steel
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2017Co-Authors: Yaxu Zheng, Fuming Wang, Changrong Li, Y HeAbstract:Abstract In order to improve the Hardenability and toughness of train axles for high-speed railway, Nb (0.04 wt%) and B (20 ppm and 36 ppm) were added in 25CrMo steel. The dissolution and the precipitation behaviors of the B bearing phase in the different austenitizing processes and their effects on Hardenability and toughness have been studied to clarify the influence mechanisms. Thermo-Calc was used to calculate the precipitation temperature, the quantity and the composition of the B bearing phase; SEM, TEM and EDS were used to investigate the morphology and the type of the B bearing phase; SIMS was used to analyze the distribution of B in steel. The results showed that the B bearing precipitates were found in the forms of different phases such as BN and M2B mainly containing Fe, Mo, Cr and B elements due to high Cr and Mo contents in steels. The excessive B atoms segregating at the austenite grain boundaries promote M2B precipitation not only during austenitizing to deteriorate the Hardenability significantly, but also during tempering to deteriorate toughness obviously. Therefore, the B content in steels should be controlled below 20 ppm, and at the same time, the austenitizing temperature and the holding time should also be optimized to avoid the adverse effect of M2B on Hardenability and impact toughness. In addition, the Hardenability and the impact toughness can be improved by a double quenching process in which both the austenitizing temperatures are low.
Byoungchul Hwang - One of the best experts on this subject based on the ideXlab platform.
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austenitizing temperature and Hardenability of low carbon boron steels
Scripta Materialia, 2011Co-Authors: Byoungchul HwangAbstract:The Hardenability of boron steels was discussed in terms of precipitation behavior and phase stability of M 23 (C,B) 6 borocarbide in accordance with austenitizing temperature. A higher austenitizing temperature reduced the Hardenability of Mo-added boron steel by the preferred precipitation of borocarbide because it caused a significant increase in boron concentration segregated to the austenite grain boundary due to grain coarsening and a non-equilibrium segregation mechanism.
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effect of molybdenum and chromium on Hardenability of low carbon boron added steels
Metals and Materials International, 2008Co-Authors: Byoungchul Hwang, Zuocheng WangAbstract:The Hardenability of low-carbon boron-added steels containing molybdenum or chromium was studied using dilatometry, thermodynamic calculations, and secondary ion mass spectroscopy (SIMS). The combined addition of boron and molybdenum was found to be more effective than that of boron and chromium in enhancing the Hardenability of boron-added steels. In particular, the addition of 0.5 wt.% molybdenum to the boron-added steel almost completely suppressed the formation of polygonal ferrite even at a slow cooling rate of 0.5°C/s. The synergistic effect of the combined addition of molybdenum and boron is thought to be due to both the suppression of M23(C,B)6 precipitation resulting from the deterioration of phase stability and the reduction of carbon diffusivity by the molybdenum addition.
Minoru Ishiguro - One of the best experts on this subject based on the ideXlab platform.
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improvement of product strength and formability in stamping of al mg si alloy sheets having bake Hardenability by resistance heat and artificial aging treatments
International Journal of Machine Tools & Manufacture, 2006Co-Authors: Kenichiro Mori, Seijiro Maki, Minoru IshiguroAbstract:Abstract Resistance heat and artificial aging treatments were introduced into a stamping operation to improve the product strength and formability of Al–Mg–Si alloy sheets having bake Hardenability used for automobile body panels. In this treatment, the sheets undergo re-solution by resistance heat treatment, composed of resistance heating and water quenching just before the stamping. Stamped sheets are artificially aged just after the stamping to increase product strength. In the experiment, Al–0.60% Si–0.74% Mg alloy sheets were chosen as an example of Al–Mg–Si alloy sheets having bake Hardenability. The re-solution solution treatment of the sheets was sufficiently accomplished by rapid resistance heat treatment, and formability of the sheets was improved. Hardness of the formed products was increased by artificial aging. It was found that the present process is effective in improving the product strength and formability of Al–Mg–Si alloy sheets having bake Hardenability due to the compactness and rapidness.
