(华南理工大学 材料科学与工程学院, 广州 510640)
摘 要: 通过研究固相Ni在静止的液相Zn中的溶解行为,建立了自然对流下的溶解速率模型, 确定了不同温度下Ni在液相Zn中的溶解控制步骤。结果表明: 450 ℃时固相Ni在液相Zn中的溶解由界面反应及溶质原子在合金相层中的扩散等因素控制; 550 ℃和650 ℃时, 溶质Ni原子通过液相Zn中浓度边界层的扩散为溶解的主要控制机制; 650 ℃时,γ相从合金层中剥离加速了Ni在液相Zn中的溶解。
关键字: 固相Ni; 液相Zn;溶解; 扩散
solid nickel in liquid zinc
(School of Materials Science and Engineering,
South China University of Technology, Guangzhou 510640, China)
Abstract: The dissolution behavior of solid nickel in static liquid zinc was studied and a natural convection model considering intermetallic compound layers formation was established to determine the rate-determining step of dissolution rate of solid nickel in liquid zinc. The results show that the dissolution process is governed by a mixed control mechanism involving diffusion of nickel atom in Ni-Zn alloy layers and the chemical reaction between solid nickel and liquid zinc at 450 ℃. At above 550 ℃, the dissolution rates are controlled by diffusion of nickel atom across a concentration boundary layer in liquid zinc, and the dissolution process seems to be accelerated as γ phase peeled off at 650 ℃.
Key words: solid nickel; liquid zinc; dissolution; diffusion