Microstructural evolution and hardening phenomenon caused by aging of AlSi10Mg alloy by laser powder bed fusion.

Microstructures and age-hardening phenomena of directly aged (artificial aged) AlSi10Mg alloys fabricated by laser powder bed fusion (LPBF) were characterized using scanning transmission electron microscopy, atom probe tomography, and Vickers hardness testing. The microstructure derived from overlapping melt pools has a full cellular structure consisting of eutectic Si walls surrounding α-Al cells. In the initial stage of aging, solute clusters with density on the order of 10/m were formed in α-Al cells.

Solute clustering and supersaturated solid solution of AlSi10Mg alloy fabricated by selective laser melting.

α-Al grains surrounded by Al-Si eutectic as the substructures in AlSi10Mg alloy fabricated by selective laser melting (SLM) were investigated in detail using three-dimensional atom-probe and transmission electron microscopy. Quantitative analysis of α-Al revealed (1) the formation of Mg clusters and Mg-Si co-clusters with a density in the order of 10 /m in α-Al of the as-built state caused by the complicated thermal history, and (2) a supersaturated Si content that significantly exceeded the maximum solubility due to rapid solidification, during the SLM process.

Autonomic nervous system activities during motor imagery in elite athletes.

Motor imagery (MI), a mental simulation of voluntary motor actions, has been used as a training method for athletes for many years. It is possible that MI techniques might similarly be useful as part of rehabilitative strategies to help people regain skills lost as a consequence of diseases or stroke. Mental activity and stress induce several different autonomic responses as part of the behavioral response to movement (e.