(南京航空航天大学 机电学院，南京 210016)
摘 要: 利用分形理论编程模拟了射流电沉积中沉积几率较小时粒子簇的生长形貌。基于模拟的原理，利用摆动射流电沉积改变了枝晶的树枝状分形生长特性，制备不同电流密度、摆动速度、NiSO4浓度和电解液温度时的二维多孔交织的金属镍枝晶簇。结果表明：随着电流密度的增大，枝晶簇开始由分形生长形态向多孔交织形态转变，分形维数也随之增大。随着摆动速度的减小，枝晶簇向致密、均匀的多孔交织形态转变明显，分形维数逐渐增大。NiSO4浓度较小时，枝晶簇的分枝较多，形貌较为致密；NiSO4浓度最大时，气泡的析出量大大减少，枝晶簇的分枝显著减少，难以形成多孔交织的组织；分形维数随NiSO4浓度的变化先增大后减小；电解液温度的升高使枝晶簇的形貌向致密型转变，分形维数逐渐增大。
关键字: 镍；枝晶；射流电沉积；分形
（College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics,
Nanjing 210016, China）
Abstract:The dendrite growth at smaller depositing probability was simulated in jet-electrodeposition with fractal theory. Based on the simulation, by swinging jet-electrodeposition, the branch-like fractal growth of dendrite was altered, the porous interlaced dendrites at different current densities, swinging steps, NiSO4 concentrations and electrolyte temperatures were prepared. The results indicate that with increasing the current density, the morphology of dendrite becomes porous with an increased fractal dimension. With decreasing the swinging speed, the dendrite growth has an obvious change to dense and uniform structure, and the fractal dimension increases gradually. When the concentration of NiSO4 is small, the dendrite has an obvious dense and uniform structure with volumes of branches. When the concentration of NiSO4 is the highest, a decrease of the H2 bubbles number leads to a large decrease of the branches number, and thus the porous interlaced dendrite cannot be prepared at this moment. The fractal dimension begins to increase and then decrease with the concentration of NiSO4 increasing. As the temperature of the electrolyte increases, the dendrite growth has a change to dense structure with the fractal dimension increasing.
Key words: Ni; dendrite; jet-electrodeposition; fractal
