10 research outputs found
Evaluation of ShortâTerm Exposure to High Temperature as a Tool to Suppress the Reproductive Development of Channel Catfish for Aquaculture
Effect of Co and Ni Addition on the Microstructure and Mechanical Properties at Room and Elevated Temperature of an Alâ7%Si Alloy
Corrosion fatigue crack growth behavior of a squeeze-cast Al-Si-Mg-Cu alloy with different precrack histories
Various Aspects Influencing the Fracture Behavior of Impact-Tested Zr-Containing AlâSiâCuâMgâ354-Type Alloys
Effect of ÎČ-Al5FeSi and Ï-Al8Mg3FeSi6 Phases on the Impact Toughness and Fractography of AlâSiâMg-Based Alloys
Development of New Al-Cu Based Alloys Aimed at Improving the Machinability of Automotive Castings
Damage by eutectic particle cracking in aluminum casting alloys A356/357
The strain dependence of particle cracking in aluminum alloys A356/357 in the T6 temper has been studied in a range of microstructures produced by varying solidification rate and Mg content, and by chemical (Sr) modification of the eutectic silicon. The damage accumulates linearly with the applied strain for all microstructures, but the rate depends on the secondary dendrite arm spacing and modification state. Large and elongated eutectic silicon particles in the unmodified alloys and large pi-phase (Al9FeMg3Si5) particles in alloy A357 show the greatest tendency to cracking. In alloy A356, cracking of eutectic silicon particles dominates the accumulation of damage while cracking of Fe-rich particles is relatively unimportant. However, in alloy A357, especially with Sr modification, cracking of the large pi-phase intermetallics accounts for the majority of damage at low and intermediate strains but becomes comparable with silicon particle cracking at large strains. Fracture occurs when the volume fraction of cracked particles (eutectic silicon and Fe-rich intermetallics combined) approximates 45 pct of the total particle volume fraction or when the number fraction of cracked particles is about 20 pct. The results are discussed in terms of Weibull statistics and existing models for dispersion hardening
EBSD Study of the Influence of a High Magnetic Field on the Microstructure and Orientation of the Al-Si Eutectic During Directional Solidification
International audienceThe effect of a high magnetic field on the morphology of the Al-Si eutectic was investigated using EBSD technology. The results revealed that the application of the magnetic field modified the morphology of the Al-Si eutectic significantly. Indeed, the magnetic field destroyed the coupled growth of the Al-Si eutectic and caused the formation of the divorced alpha-Al and Si dendrites at low growth speeds (a parts per thousand currency sign1 mu m/s). The magnetic field was also found to refine the eutectic grains and reduce the eutectic spacing at the initial growth stage. Moreover, the magnetic field caused the occurrence of the columnar-to-equiaxed transition of the alpha-Al phase in the Al-Si eutectic. The abovementioned effects were enhanced as the magnetic field increased. This result should be attributed to the magnetic field restraining the interdiffusion of Si and Al atoms in liquid ahead of the liquid/solid interface and the thermoelectric magnetic force acting on the eutectic lamellae under the magnetic field