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目的研究工艺参数中的气压、偏压、弧电流对该涂层沉积速率、组织结构、成分的影响。方法采用电弧离子镀技术,利用正交试验改变气压、偏压、弧电流三种工艺参数,在镍高温合金上制备NiCoCrAlYTa涂层,借助SEM分析涂层的截表面形貌,EDS检测涂层成分,金相显微镜检测涂层的孔隙率,3D轮廓仪测量涂层厚度。结果弧电流对沉积速率的影响最大,其次为偏压,最小的是气压;偏压对涂层孔隙率的影响最大,其次为气压,最小的是弧电流。随着偏压的增大,涂层由柱状结构转变成层状结构。随着电流增大,涂层表面大颗粒数量先增后减。涂层成分相对靶材成分都发生了离析,涂层中的Ni、Al含量较靶材的下降,Co、Cr含量较靶材的上升,并且随着偏压的增大,成分离析加剧;随着电流的增加,成分离析先加剧后减弱;气压对成分离析的影响不明显。结论低气压和高电流有利于提高涂层的致密性,并减弱涂层成分的离析,减少涂层中重要元素Al的流失。实验得出的最优工艺为气压0.5 Pa,电流110 A,偏压可根据性能检测进一步优化。
Objective To study the influence of air pressure, bias voltage and arc current on the deposition rate, microstructure and composition of the coating. Methods By using arc ion plating technique, the NiCoCrAlYTa coating was prepared on nickel superalloy by changing the pressure, bias voltage and arc current using orthogonal test. The surface morphology of the coating was analyzed by SEM, and the coating composition , The metallographic microscope to detect the porosity of the coating, 3D profiler to measure the thickness of the coating. Results Arc current had the most influence on the deposition rate, followed by bias voltage and the smallest pressure. The influence of bias voltage on the porosity of the coating was the largest, followed by the air pressure and the minimum was the arc current. As the bias voltage increases, the coating changes from a columnar structure to a layered structure. As the current increases, the number of large particles on the coating surface increases first and then decreases. The composition of the coating relative to the target components are segregated, the coating Ni, Al content than the target decreased, Co, Cr content than the target increased, and with the bias voltage increases, the component separation intensified; with With the increase of current, the component segregation intensified first and then weakened; the effect of pressure on component segregation was not obvious. Conclusions Low pressure and high current are beneficial to improve the densification of coatings and reduce the segregation of coating components and reduce the loss of Al, an important element in coatings. The optimum experimental process is 0.5 Pa pressure, 110 A current bias can be further optimized according to the performance test.