Automatic Reconstruction of Dendrite Morphology from Optical Section Stacks

Author(s):  
S. Urban ◽  
S. M. O’Malley ◽  
B. Walsh ◽  
A. Santamaría-Pang ◽  
P. Saggau ◽  
...  
1958 ◽  
Vol 35 (2) ◽  
pp. 396-399
Author(s):  
SHOZO ISHIZAKA

1. The surface movements during division have been studied by marking the naked surface of the sea-urchin egg with charcoal particles. 2. The contours of the largest optical section, the positions of the particles thereon and the positions of the astral centres are recorded in a series of camera lucida drawings. 3. The drawings are then superimposed, the centre of gravity and spindle axis being used for reference. 4. It is thereby shown that there are two surface rings which remain in the same positions throughout the whole process of division. 5. It is concluded that these rings indicate regions where stresses remain balanced during division.


2022 ◽  
Vol 327 ◽  
pp. 82-97
Author(s):  
He Qin ◽  
Guang Yu Yang ◽  
Shi Feng Luo ◽  
Tong Bai ◽  
Wan Qi Jie

Microstructures and mechanical properties of directionally solidified Mg-xGd (5.21, 7.96 and 9.58 wt.%) alloys were investigated at a wide range of growth rates (V = 10-200 μm/s) under the constant temperature gradient (G = 30 K/mm). The results showed that when the growth rate was 10 μm/s, different interface morphologies were observed in three tested alloys: cellular morphology for Mg-5.21Gd alloy, a mixed morphology of cellular structure and dendritic structure for Mg-7.96Gd alloy and dendrite morphology for Mg-9.58Gd alloy, respectively. Upon further increasing the growth rate, only dendrite morphology was exhibited in all experimental alloys. The microstructural parameters (λ1, λ2) decreased with increasing the growth rate for all the experimental alloy, and the measured λ1 and λ2 values were in good agreement with Trivedi model and Kattamis-Flemings model, respectively. Vickers hardness and the ultimate tensile strength increased with the increase of the growth rate and Gd content, while the elongation decreased gradually. Furthermore, the relationships between the hardness, ultimate tensile strength, the growth rate and the microstructural parameters were discussed and compared with the previous experimental results.


2021 ◽  
Vol 1035 ◽  
pp. 46-50
Author(s):  
Lei Gang Cao ◽  
Peng Yu Hou ◽  
Ahmed Nassar ◽  
Andrew M. Mullis

Mould casting and drop-tube techniques were used to solidify a AlCoCrFeNi2.1 eutectic high-entropy alloy under conditions of high cooling rate. The samples obtained from two different methods present the same phase constituent, FCC and B2 phases. During mould casting experiments the alloy almost solidified into the eutectic structure consisting of lamellar and anomalous morphology, with a tiny fraction of cellular and dendrite morphology being observed at certain sites of the sample surface due to the corresponding high cooling rate. Instead, during drop-tube experiments a typical, coarse dendrite structure of FCC single phase was formed across the entire 106-150 μm particle. The cellular structure can also be formed directly from the melt. The rest region solidified into the general eutectic morphology as was observed in the casting rods. The results clearly indicate the transition from coupled eutectic growth to single-phase dendrite growth with increasing departures from equilibrium for the multi-component AlCoCrFeNi2.1 eutectic high-entropy alloy.


2013 ◽  
Vol 99 (2) ◽  
pp. 126-134 ◽  
Author(s):  
Ryosuke Sugawara ◽  
Toshihisa Itoh ◽  
Yukinobu Natsume ◽  
Kenichi Ohsasa

2019 ◽  
Vol 38 (2019) ◽  
pp. 567-575 ◽  
Author(s):  
Qingfu Tang ◽  
Dong Chen ◽  
Bin Su ◽  
Xiaopeng Zhang ◽  
Hongzhang Deng ◽  
...  

AbstractThe microstructure evolution of U-Nb alloys during solidification and consequent cooling process was simulated using a cellular automaton (CA) model. By using this model, ϒ phase precipitation and monotectoid decomposition were simulated, and dendrite morphology of ϒ phase, Nb microsegregation and kinetics of monotectoid decomposition were obtained. To validate the model, an ingot of U-5.5Nb (wt.%) was produced and temperature measuring experiment was carried out. As-cast microstructure at different position taken from the ingot was investigated by using optical microscope and SEM. The effect of cooling rate on ϒ phase precipitation and monotectoid decomposition of U-Nb alloys was also studied. The simulated results were compared with the experimental results and the capability of the model for quantitatively predicting the microstructure evolution of U-Nb alloys during solidification and consequent cooling process was assessed.


Author(s):  
Csaba Póliska ◽  
Zoltán Gácsi ◽  
Péter Barkóczy

Sign in / Sign up

Export Citation Format

Share Document