Formation mechanism of microstructure in two-phase zone continuous casting Cu–Sn alloy

2018 ◽  
Vol 529 (1) ◽  
pp. 33-42
Author(s):  
Jihui Luo ◽  
Xuefeng Liu ◽  
Kun Yang
2016 ◽  
Vol 16 (1) ◽  
pp. 33-40 ◽  
Author(s):  
J. Luo ◽  
X. Liu ◽  
X. Wang

Abstract Cu–4.7 wt. % Sn alloy wire with Ø10 mm was prepared by two-phase zone continuous casting technology, and the temperature field, heat and fluid flow were investigated by the numerical simulated method. As the melting temperature, mold temperature, continuous casting speed and cooling water temperature is 1200 °C, 1040 °C, 20 mm/min and 18 °C, respectively, the alloy temperature in the mold is in the range of 720 °C–1081 °C, and the solid/liquid interface is in the mold. In the center of the mold, the heat flow direction is vertically downward. At the upper wall of the mold, the heat flow direction is obliquely downward and deflects toward the mold, and at the lower wall of the mold, the heat flow deflects toward the alloy. There is a complex circular flow in the mold. Liquid alloy flows downward along the wall of the mold and flows upward in the center.


2013 ◽  
Vol 23 (1) ◽  
pp. 94-101 ◽  
Author(s):  
Xuefeng Liu ◽  
Jihui Luo ◽  
Xiaochen Wang ◽  
Lin Wang ◽  
Jianxin Xie

2016 ◽  
Vol 850 ◽  
pp. 610-617 ◽  
Author(s):  
Ji Hui Luo ◽  
Xue Feng Liu ◽  
Lai Xin Shi ◽  
Chang Fei Cheng

Surface segregation exists in two-phase zone continuous casting (TZCC) alloy with wide solid–liquid two phase zone. The surface segregation formation cannot be explained by the traditional solidification theories. ProCAST software was used to simulate the TZCC process for preparing the Cu–4.7 wt%Sn alloy with wide solid–liquid two phase zone. The Sn solute distribution in TZCC Cu–4.7 wt%Sn alloy was investigated, and the surface segregation mechanism of TZCC Cu–4.7 wt%Sn alloy was analyzed. The results showed that numerical simulation results were agreed with that of experimental. TZCC Cu–4.7 wt%Sn alloy in the center firstly started to solidify and resulted in “Λ” shape inclined solid/liquid (S/L) interface near the mold. Therefore, a narrow gap between the wall of the two-phase zone mold and the S/L interface formed. On the one hand, while Cu–4.7 wt%Sn alloy solidified along the opposite continuous casting direction, the solute redistribution between the solid and the liquid occurred, which lead to Sn solute decreased in solid and enriched in front of S/L interface. Because the narrow gap lies in front of inclined S/L interface near the two-phase zone mold, Sn solute enriches in liquid of the narrow gap. On the other hand, during the TZCC process, solid grains nucleate on the wall of the two-phase zone mold, while the melt feeds into the two-phase zone mold which the temperature is in the two-phase zone of the Cu–4.7 wt%Sn alloy. The solute redistribution also occurs while the solid grains grow, thus lead to Sn content increases in front of S/L interface near the wall of the two-phase zone mold. The enriched Sn solute is too late to diffuse, and will quickly flows into the narrow gap, resulting in further increasing of Sn content in the narrow gap. The liquid with enriched Sn solute in the narrow gap will become the surface layer after solidification, which lead to surface segregation layer during the TZCC Cu–4.7 wt%Sn alloy.


2003 ◽  
Vol 17 (08n09) ◽  
pp. 1503-1509
Author(s):  
Ma Ying ◽  
Hao Yuan ◽  
Feng Yun Yan ◽  
Hong Jun Liu ◽  
Chang Min Suh

The continuous directional solidification technique of 5 kinds of special ZA alloys with eutectic, eutectoid and peritectic transformations under the condition of continuous casting by heated mold was studied. The optimum fitting range of technique factors in each alloy is found. The results show that the operation of guiding ingot is the key of the technique to produce directional solidification ZA alloy line by heated mold in continuous casting method. Outlet temperature, pulling speed, cooling condition, alloy composition and pressure head have direct influences on the surface quality of ingot. There is a balance between heat and force in the two-phase zone of solid and liquid. Only adjusting technique parameters with the balance and keeping a good place of the interface between solid and liquid, can the smooth ZA alloy line be continuously pulled out.


2017 ◽  
Vol 10 (1) ◽  
pp. 13-22
Author(s):  
Renyi Cao ◽  
Junjie Xu ◽  
Xiaoping Yang ◽  
Renkai Jiang ◽  
Changchao Chen

During oilfield development, there exist multi-cycle gas–water mutual displacement processes. This means that a cycling process such as water driving gas–gas driving water–water driving gas is used for the operation of injection and production in a single well (such as foam huff and puff in single well or water-bearing gas storage). In this paper, by using core- and micro-pore scales model, we study the distribution of gas and water and the flow process of gas-water mutual displacement. We find that gas and water are easier to disperse in the porous media and do not flow in continuous gas and water phases. The Jamin effect of the gas or bubble becomes more severe and makes the flow mechanism of multi-cycle gas–water displacement different from the conventional water driving gas or gas driving water processes. Based on experiments of gas–water mutual displacement, the changing mechanism of gas–water displacement is determined. The results indicate that (1) after gas–water mutual displacement, the residual gas saturation of a gas–water coexistence zone becomes larger and the two-phase zone becomes narrower, (2) increasing the number of injection and production cycles causes the relative permeability of gas to increase and relative permeability for water to decrease, (3) it becomes easier for gas to intrude and the invaded water becomes more difficult to drive out and (4) the microcosmic fluid distribution of each stage have a great difference, which caused the two-phase region becomes narrower and effective volume of gas storage becomes narrower.


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