2024铝合金浸镍层的制备及生长过程

利用磷酸的全面腐蚀特性和氯离子的活化作用，设计了磷酸-氯化镍浸镍反应体系，通过表面电位监测及微观形貌表征对不同磷酸浓度与反应温度下的浸镍过程进行分析。结果表明:磷酸浓度是影响浸镍层表面电位及微观形貌的关键因素，当磷酸浓度为25%，反应温度为30℃时，可制得化学性质稳定、包覆性良好且晶粒尺寸均匀的浸镍层。在此反应体系下，浸镍层在形核后通过球状方式叠层生长，在反应进行600 s后得到厚度约1 μm的浸镍层，其表面电位可达到-0.51 V左右。 

Preparation and growth processes of nickel-immersed coating on 2024 aluminum alloy

A phosphoric acid-nickel chloride reaction system was designed by utilizing the comprehensive corrosion properties of phosphoric acid and the activation effect of chloride ions. By characterizing surface potential and microscopic morphology, the nickel immersion process was analyzed at different phosphoric acid concentration and temperature. The result shows that the concentration of phosphoric acid is a key factor affecting the surface potential and morphology of the nickel-immersed coating. When the concentration of phosphoric acid is 25% and the temperature is 30℃, nickel-immersed coating with stable chemical properties, good coating and uniform grain size can be prepared. In this reaction system, the nickel-immersed coating grows in a spherical manner after nucleation. After reacting for 600 s, a nickel-immersed coating with a thickness of about 1 μm is obtained, and its surface potential can reach about -0.51 V.