激光同步辐照对电化学沉积铜组织结构及结合力的影响

目的 解决单一电化学沉积制备铜镀层沉积速度慢、沉积颗粒易团聚、晶粒生长不均匀及其与基体结合力差等问题。方法 采用沉积前激光处理、沉积过程激光同步辐照的方法，在316L不锈钢上制备铜涂层，通过光学显微镜、扫描电子显微镜、自动划痕仪分析了铜镀层表面形貌、截面厚度、涂层物相和结合力，探究了激光的增强作用和复合沉积技术下镀层的生长机制。结果 激光同步辐照促进了晶粒的高择优取向及沉积电位的正移。单一晶面的高择优取向利于提高镀层晶粒生长的均匀性，使镀层表面的凸起、孔洞明显减少，变得平整致密。同时，激光同步辐照使镀层表面粗糙度维持在一个较低的范围，使沉积质量不会随沉积时间的增加而降低，有利于电化学沉积的继续进行，实现镀层增厚。相同沉积时间(60 min)下，传统电化学沉积所得镀层的沉积厚度为62.62μm，表面粗糙度为4.741μm；而激光同步复合电化学沉积所得镀层的沉积厚度为138.39μm，表面粗糙度为0.995μm；且镀层表现出与基体更佳的结合力，与基体间的极限载荷可达98.2 N。结论 激光同步辐照提高了铜镀层的沉积效率、质量及其与基体间的结合力。

Effect of Laser Synchronous Irradiation on Microstructure and Binding Force of Electrodeposition Copper

To solve the problems of slow deposition, easy agglomeration of deposited particles, and uneven grain growth of copper coating prepared by conventional electrodeposition. In this paper, the method of laser-assisted synchronous composite electrodeposition was adopted, that was, by combining laser technology with electrodeposition technology, the preparation of high-quality and highly localized copper coating on 316L stainless steel was realized and the surface morphology, cross-section thickness, coating phase and binding force of copper coating were analyzed by optical microscope, scanning electron microscope and automatic scratch meter. In addition, the growth mechanism of coating under the enhancing effect of laser and composite deposition technology was explored. At the early stage of deposition, under the influence of laser microwoven structure, the copper crystals deposit grew along the microwoven epitaxial growth, resulting in a large cell-like bump, a wavy shape of the plating cross-section and poor flatness of the plating surface. With the accumulation of laser energy, the rate of cathodic reduction reaction was accelerated, the uniformity of grain growth on the surface of the coating was improved, and the compactness of the coating was improved. At the same time, the micro-stirring generated by the shock wave promoted charge transfer and reduced the concentration gradient of the deposited liquid. This facilitated the transfer of copper ions to the cathode matrix, providing copper ions for the reduction reaction. Due to the low current density used in the experiment, the number of copper atom-shaped nuclei was relatively small, and as the deposition time increased, the copper grains grew to a certain size and merged with the surrounding grains to form a flake structure, and the grain size became larger. Laser synchronous irradiation promoted a high preference orientation of the grains and the positive shift of the deposited potential. The high preferential orientation of a single crystal surface was conducive to improving the uniformity of the grain growth of the coating, so that the bulges and holes on the surface of the coating were significantly reduced, and it became flat and dense. So that the surface roughness of the coating was maintained in a low range, and the deposition quality would not decrease with the increase of the deposition time, which was conducive to the continuation of electrodeposition and the thickening of the coating. Under the same deposition time (60 min), the deposition thickness of the conventional electrodeposition coating was 62.62 mm and the surface roughness was 4.741 mm, while the deposition thickness of the plating obtained by laser-assisted synchronous composite electrodeposition was 138.39 mm. The surface roughness was 0.995 mm, and the coating exhibited better adhesion to the substrate. And the coating showed a better binding force with the substrate. The edges and ends of the plating scratches resulting from conventional electrodeposition had a small area of shedding, and the ultimate load between the substrate and the substrate was 83.8 N. The edges and ends of the coating scratches obtained by laser-assisted synchronous composite electrodeposition became leveling, and the ultimate load between the laser and the substrate could reach 98.2 N. Laser synchronous irradiation can improve the deposition quality of the copper coating and its binding force to the matrix.