To eliminate the unfavorable effect of the column grains, great efforts have been made to achieve the equiaxial grain morphology by investigating the columnar to equiaxed transition (CET) phenomenon with the help of numerical models [12,40,41]. Show moreView article Journal 2020, Additive ...
These figures demonstrate the beneficial effect of increasing the WFS as it clearly leads to a transition to a smaller, more-equiaxed, grain structure. Although the refined grains are still relatively coarse, having a 0.5–2 mm grain size and an aspect ratio of ~ 1.5, they are much fin...
grain sizetensile strengthtitanium alloysyield stress/ directionally solidified Al-Cu-Titensile strengthThe tensile properties of directionally solidified Al-4 wt pct Cu-0.15-0.2 wt pct Ti alloys with equiaxed grains were determined and compared with the properties of directionally solidified Al-4 wt ...
The reduced pellet, UO2+x, has a special grain structure that consists of equiaxed grains at the surface, columnar grains in the middle, and equiaxed grains in the center. The equiaxed grains and columnar grains are much smaller in H2 gas than in Ar or CO2 gas. The reducing gases ...
GRAIN sizeA phase-field model was applied to study CET (columnar-to-equiaxed transition) during laser welding of an Al-Cu model alloy. A parametric study was performed to investigate the effects of nucleation undercooling for the equiaxed grains, nucleation density and location of the ...
The reduced pellet, UO2+x, has a special grain structure that consists of equiaxed grains at the surface, columnar grains in the middle, and equiaxed grains in the center. The equiaxed grains and columnar grains are much smaller in H2 gas than in Ar or CO2 gas. The reducing gases ...
Typically, the grains are growing because the grain surface has extra energy (surface energy) and larger grains have less surfaces per grain volume compared to smaller grains. At high temperatures, the growth can be fast because of the good kinetic conditions (fast diffusion), but at lower ...
The size of the equiaxed grains increases with distance from the transition, an observation that was independent of alloy composition. The observations indicate that the transition is the result of a competition between coarse columnar dendrites and finer equiaxed dendrites. The results are compared ...
The sample with equiaxed grains is found to have a low PC score while the sample with columnar grain had a high PC score. A semi-analytical model is used to simulate the heat transfer and the local solidification conditions as a function of processing parameters (linear spot-density). The ...
ductility differences were also discovered in horizontally and vertically built test specimens [23,25,37]. To eliminate the unfavorable effect of the column grains, great efforts have been made to achieve the equiaxial grain morphology by investigating the columnar to equiaxed transition (CET) phenome...