超音速火焰喷涂NiCr-Cr_3C_2-BaF_2·CaF_2/NiCr-Cr_3C_2涂层的制备及抗热震性能  

HVOF Fabrication and Thermal Shock Resistance of NiCr-Cr_3C_2-BaF_2·CaF_2/NiCr-Cr_3C_2 Coating

作　　者：邝子奇[1] 邓畅光[1] 牛少鹏[1,2] 曾威[1] 

机构地区：[1]广州有色金属研究院,广东广州510651 [2]华南理工大学材料科学与工程学院,广东广州510640

出　　处：《材料科学与工程学报》2015年第3期319-323,共5页Journal of Materials Science and Engineering

摘　　要：本文采用超音速火焰喷涂方法(HVOF)制备了NiCr-Cr3C2-BaF2·CaF2/NiCr-Cr3C2和NiCr-Cr3C2-BaF2·CaF2两种涂层,对两种涂层试样进行了热冲击试验,研究了涂层的抗热震性能,并探讨了涂层的热疲劳特性。结果表明:NiCr-Cr3C2-BaF2·CaF2/NiCr-Cr3C2涂层热震75次后仍保持表面平整,相同条件下的NiCr-Cr3C2-BaF2·CaF2涂层热震5次即剥落;NiCr-Cr3C2中间层的引入缓和了涂层内应力,阻碍了热疲劳裂纹形成和扩展。在热冲击试验中基体与中间层之间形成的扩散层可吸收裂纹尖端应力,阻止裂纹进一步失稳扩展。Two coatings,NiCr-Cr3C2-BaF2·CaF2/NiCr-Cr3C2 and NiCr-Cr3C2-BaF2·CaF2,were prepared by high velocity oxy-fuel spraying（HVOF）method.For the two coatings thermal shock test was conducted,and thermal shock resistance and thermal fatigue properties were studied and analyzed.It is found that NiCr-Cr3C2-BaF2·CaF2coating has peeled off after barely 5times of thermal shock,while NiCr-Cr3C2-BaF2·CaF2/NiCr-Cr3C2 coating surface can remain complete and uniform after 75 times due to the adoption of NiCrCr3C2 bond coating under the same test conditions.The results show that NiCr-Cr3C2 bond coating can contribute to remit thermal stress of the coating,delay thermal fatigue crack initiation and inhibit crack propagation.The diffusion layer which formed on the interface between bond layer and substrate in thermal shock can absorb crack-tip stress and prevent the crack from further instable propagation.

关 键 词：HVOF NiCr-Cr3C2-BaF2·CaF2/NiCr-Cr3C2涂层 抗热震性能 

分 类 号：TG174.44[金属学及工艺—金属表面处理]