PS-PVD工艺中非视线沉积对涂层微结构的影响  

Effect of non-line-of-sight deposition on coating microstructure in PS-PVD process

作　　者：李新慧 何箐[1,2] 邹晗[1,2] 由晓明[1,2] 赵乾 Li Xinhui;He Qing;Zou Han;You Xiaoming;Zhao Qian(Surface Engineering Research Institute,Chinese Academy of Agricultural Mechanization Sciences,Beijing 100083,China;Beijing JinLunKunTian Special Machine Co.,Ltd.,Beijing 100083,China)

机构地区：[1]中国农业机械化科学研究院表面工程技术研究所,北京100083 [2]北京金轮坤天特种机械有限公司,北京100083

出　　处：《热喷涂技术》2023年第2期34-41,共8页Thermal Spray Technology

摘　　要：等离子喷涂-物理气相沉积(PS-PVD)工艺由于具有非视线沉积效果,在加工复杂型面和多联体导向叶片表面热障涂层具有高均匀性的优势而被广泛关注。为了进一步研究PS-PVD高能、高速射流的非视线沉积效果,验证固定直径圆柱挡杆(Φ22 mm)不同距离遮蔽对平面沉积样品沉积行为的影响。结果表明:无遮蔽条件下,基体表面涂层厚度分布呈中部厚而四周薄,呈现高斯峰分布特征,涂层最大厚度为135μm;有遮挡条件下,涂层厚度呈现双峰的结构特征,在15 mm的遮挡距离时,遮挡区域基体沉积的涂层最薄,其他遮挡距离下,涂层厚度在0~40μm之间变化。对遮蔽区域位置涂层显微形貌进行分析,发现不同位置的遮蔽区域正后方,气相的速率和浓度明显降低,导致柱状结构生长时形成气相沉积为主的结构,同时扩散速率较低导致气相生长较慢;在遮蔽区域的边缘,由于遮蔽效应,涂层中的冷凝颗粒明显增多;遮蔽区域涂层厚度明显降低,且挡杆距基体距离越远,遮蔽区域的厚度分布越不规则,受射流的扰动影响越大。Plasma spray-physical vapor deposition(PS-PVD)process has attracted wide attention due to its nonline-of-sight(NLOS)deposition effect,which has the advantage of high uniformity of thermal barrier coatings on the surface of complex processing and multiple vanes.In order to further studying the NLOS deposition effect of high energy and high speed of PS-PVD jets,different deposition distances were used to verify the influence rule of fixed diameter cylindrical shield(Φ22 mm)on deposition behavior of planar deposition samples.The results show that as the thickness distribution of the coating on the surface of the substrate is thick in the middle and thin in the periphery in the absence of shielding,showing the characteristics of Gaussian peak distribution,and the maximum thickness of the coating is 135μm.The coating thickness presents a bimodal structure under the condition of shielding,the thickness of the coating in the shadowing area is the thinest when the deposition distance was 15 mm,and at other deposition distances,the coating thickness varies between 0 and 40μm.The microstructure of shadowing area was analyzed,it is found that the velocity and concentration of the gas phase decrease obviously behind the shadowing area,which leads to the formation of vapor deposition when the columnar structure grows.Meanwhile,the lower diffusion rate leads to the slower growth of gas phase.At the edge of the shadowing area,the condensation particles in the coating increase obviously due to the shadowing effect.From the coating thickness distribution in the shadowing area,the longer distance between the cylindrical shield and the substrate,the more irregular the thickness distribution in the shadowing area and the greater the influence of jet disturbance.

关 键 词：等离子喷涂-物理气相沉积 非视线沉积 遮蔽效应 显微结构 

分 类 号：TG174.4[金属学及工艺—金属表面处理]