(南京航空航天大學(xué) 機(jī)電學(xué)院，南京 210016)
摘 要: 利用分形理論編程模擬了射流電沉積中沉積幾率較小時(shí)粒子簇的生長形貌。基于模擬的原理，利用擺動(dòng)射流電沉積改變了枝晶的樹枝狀分形生長特性，制備不同電流密度、擺動(dòng)速度、NiSO4濃度和電解液溫度時(shí)的二維多孔交織的金屬鎳枝晶簇。結(jié)果表明：隨著電流密度的增大，枝晶簇開始由分形生長形態(tài)向多孔交織形態(tài)轉(zhuǎn)變，分形維數(shù)也隨之增大。隨著擺動(dòng)速度的減小，枝晶簇向致密、均勻的多孔交織形態(tài)轉(zhuǎn)變明顯，分形維數(shù)逐漸增大。NiSO4濃度較小時(shí)，枝晶簇的分枝較多，形貌較為致密；NiSO4濃度最大時(shí)，氣泡的析出量大大減少，枝晶簇的分枝顯著減少，難以形成多孔交織的組織；分形維數(shù)隨NiSO4濃度的變化先增大后減小；電解液溫度的升高使枝晶簇的形貌向致密型轉(zhuǎn)變，分形維數(shù)逐漸增大。
關(guān)鍵字: 鎳；枝晶；射流電沉積；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
