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基于相场法对Ni-Cu合金的定向凝固过程进行了数值模拟,对比研究了抽拉速度、温度梯度对有/无强制流动下的凝固界面形貌的影响。结果表明,在强制流动的作用下,凝固界面向迎流方向倾斜生长;随着强制流速的增大,胞晶增大,沟槽的倾斜深度也逐渐增大,并且胞晶间的深度差别增大;在流动条件下,随着抽拉速度的增大,定向凝固界面演变模式为:平界面→深胞→浅胞→平界面,随着温度梯度的增大,凝固界面演化模式为:深胞→浅胞→平界面。此外,流动对凝固形成的胞晶一次间距产生重要影响。
The phase-field method was used to simulate the directional solidification of Ni-Cu alloy. The effects of drawing speed and temperature gradient on the morphology of the solidified interface were investigated. The results show that the solidification interface grows obliquely toward the Yingliu flow under the forced flow. As the forced flow rate increases, the cell growth increases and the depth of the groove gradually increases, and the depth difference between the intergranular In the flowing condition, with the increase of the drawing speed, the evolutional mode of the directional solidification interface is: flat interface → deep cell → shallow cell → flat interface. With the increase of temperature gradient, the evolution mode of solidified interface is deep Cells → cells → flat interface. In addition, the flow has an important effect on the primary spacing of the crystalline cells formed by solidification.