摘要
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。
The work aims to study the effect of technological parameters （pressure, bias voltage and arc current） on deposition rate, microstructure and composition of coatings. The NiCoCrAlYTa coatings were deposited on nickel-based superalloy by changing air pressure, bias voltage and arc current in orthogonal experiment by arc ion plating （AIP）. The cross-section and surface morphology of the coatings were analyzed by SEM, composition was detected by EDS, porosity was detected by metallographic microscope and thickness was examined by 3D contourgraph. Arc current had most significant effect on deposition rate of coatings, bias voltage the second and air pressure the least. However, the bias voltage had most significant effect on porosity of the coatings, air pressure the second and arc current the least. The coating microstructures transformed from columnar to lamellar structure with the increase of bias voltage. The number of large particles on the coatings first increased and then decreased with the increase of arc current. The coating composition was subject to segregation with respect to that of target. Compared with the target, the Ni and Al content of the coatings decreased while Co and Cr content of the coatings increased. The composition segregation effect intensified with the increase of bias voltage. However, it first intensified and then weakened with the increase of arc current. Air pressure had no obvious impact on composition segregation. Low air pressure and high current can improve the compactness of NiCoCrAlYTa coating, decrease the composition segregation and reduce loss of Al, a vital element in the coatings. The optimal technological parameters obtained in experiment were： air pressure of 0.5 Pa and arc current of 110 A, the bias voltage can be further optimized by examining relevant performance.
出处
《表面技术》
EI
CAS
CSCD
北大核心
2017年第1期29-35,共7页
Surface Technology
基金
广东省自然科学基金研究团队项目(2016A030312015)~~
