(NiCoCrAlYSiB+AlSiY)复合涂层热腐蚀行为的研究

IMR OpenIR

	(NiCoCrAlYSiB+AlSiY)复合涂层热腐蚀行为的研究
	卢旭阳
学位类型	硕士
导师	孙超
	2012
学位授予单位	中国科学院金属研究所
学位授予地点	北京
学位专业	材料加工工程
关键词	电弧离子镀复合涂层热腐蚀 Arc Ion Plating (Aip) Composite Coating Hot Corrosion
摘要	"本论文以镍基单晶高温合金为基材，采用电弧离子镀技术制备了NiCoCrAlYSiB涂层（普通涂层）和(NiCoCrAlYSiB+AlSiY)复合涂层，分析了涂层的组织结构，研究了高温合金基体与2种涂层分别在700和900℃下的涂盐(Na2SO4+K2SO4和Na2SO4+NaCl)热腐蚀行为。 NiCoCrAlSiY普通涂层和(NiCoCrAlYSiB+AlSiY)复合涂层在退火前后组织均匀致密，与基体结合良好。(NiCoCrAlYSiB+AlSiY)复合涂层经过退火处理后，明显分为内外两层，外层主要由β-(Ni,Co)Al相组成，同时包括少量的α-Cr相和Cr3Si相；内层的结构与普通涂层类似。(NiCoCrAlYSiB+AlSiY)复合涂层经过退火处理后，Al元素外层高内层低、Cr元素外层低内层高，呈梯度分布。在Na2SO4+K2SO4混合盐中700℃热腐蚀600h后，合金基体上可以观察到深度3-5μm的腐蚀坑，而2种涂层的热腐蚀侵蚀深度都很小。经过热腐蚀之后，基体合金的表面腐蚀产物有NiO；NiCoCrAlYSiB普通涂层的表面有γ´/γ相；(NiCoCrAlYSiB+AlSiY)复合涂层的表面有β-(Ni,Co)Al相。在Na2SO4+NaCl混合盐中700℃热腐蚀200h后，基体合金表面被腐蚀，表面下20μm深度内出现了密集的内氧化和内硫化，表面腐蚀产物有NiO；NiCoCrAlYSiB普通涂层表面生成3-5μm厚的氧化膜，内氧化深入到整个涂层，表面腐蚀产物有Cr2O3；(NiCoCrAlYSiB+AlSiY)复合涂层的表面产生了厚度10μm以上的氧化膜，表面腐蚀产物有Al2O3。在Na2SO4+K2SO4混合盐中900℃热腐蚀100h后，基体合金腐蚀较严重，表面腐蚀产物有NiO、(Ni,Co)(Cr,Al)2O4尖晶石和Na(Ta,Nb)O3；NiCoCrAlYSiB普通涂层表面生成了1-3μm厚的氧化膜，同时在涂层内部出现了内氧化，表面腐蚀产物有Cr2O3；(NiCoCrAlYSiB+AlSiY)复合涂层表面生成了超过3μm厚的氧化膜，涂层内出现了2-5μm厚的“贫Al区”，表面仍然有β-(Ni,Co)Al相存在，同时有γ´/γ相、Al2O3以及少量NiCoCr相生成。在Na2SO4+NaCl混合盐中900℃热腐蚀40h后，基体合金腐蚀严重，出现了较多内氧化，腐蚀侵蚀深度达到40-50μm，表面腐蚀产物有NiO、(Ni,Co)(Cr,Al)2O4尖晶石和Na(Ta,Nb)O3；NiCoCrAlYSiB普通涂层表面生成了不连续的氧化膜，涂层中出现了遍及整个涂层的严重内氧化，表面腐蚀产物有Cr2O3；(NiCoCrAlYSiB+AlSiY)复合涂层外层出现了密集的内氧化，内氧化边缘有大量的“贫Al区”，表面仍有β-(Ni,Co)Al相存在，同时生成γ´/γ相和Al2O3。"
其他摘要	"Two kinds of the coatings, the conventional NiCoCrAlYSiB coating and the composite coating (NiCoCrAlYSiB+AlSiY), were prepared using arc ion plating (AIP) on the Ni base single crystal superalloy substrate. Microstructure of the two coatings was characterized. Comparative studies of the hot corrosion behaviors in Na2SO4+K2SO4 and Na2SO4+NaCl at 700 and 900℃ of the substrate and two different coatings were investigated. The microstructure of the NiCoCrAlYSiB coating and the (NiCoCrAlYSiB+AlSiY) coating was uniform and compact before and after the annealing treatment. The two coatings combined with the base superalloy substrate very well. After the annealing treatment, the (NiCoCrAlYSiB+AlSiY) coating obviously divided into two layers inside and outside. The outer layer consisted of β-(Ni,Co)Al phase and a small amount of α-Cr and Cr3Si. The inner layer structure is similar to the NiCoCrAlYSiB coating. The (NiCoCrAlYSiB+AlSiY) coating’s elements (Al, Cr) assume the gradient distribution with the Al entiched outer layer and the Cr enriched inner layer. After the hot corrosion in Na2SO4+K2SO4 at 700℃ for 600 h, there was 3-5μm corrosion pit in the substrate alloy, and surface corrosion products contain NiO. Both the hot corrosion erosion depths of the two coatings were small. The surface substance of NiCoCrAlYSiB coating contains γ´/γ, while the surface substance of (NiCoCrAlYSiB+AlSiY) coating contains β-(Ni,Co)Al. After the hot corrosion in Na2SO4+NaCl at 700℃ for 200 h, the substrate alloy was eroded with dense internal oxidation and sulfidation in the depth of 20 μm, and surface corrosion products contain NiO. 3-5 μm thick oxidation scale generated on the surface of NiCoCrAlYSiB coating while internal oxidation appeared in the whole coating, and surface corrosion products contain Cr2O3. More than 10 μm thick oxidation scale was formed on the surface of the (NiCoCrAlYSiB+AlSiY) coating, and the surface corrosion products contain Al2O3. After the hot corrosion in Na2SO4+K2SO4 at 900℃ for 100 h, the substrate alloy was eroded heavily, and surface corrosion products contain NiO, (Ni,Co)(Cr,Al)2O4 spinel and Na(Ta,Nb)O3. 1-3 μm thick oxidation scale generated on the surface of NiCoCrAlYSiB coating while internal oxidation appeared, and surface corrosion products contain Cr2O3. More than 3 μm thick oxidation scale was formed on the surface of the (NiCoCrAlYSiB+AlSiY) coating while 2-5 μm thick ‘Al depletion area’ appeared in the coating, and β-(Ni,Co)Al, γ´/γ, Al2O3 and a small amount of NiCoCr existed on the surface of (NiCoCrAlYSiB+AlSiY) coating. After the hot corrosion in Na2SO4+NaCl at 900℃ for 40 h, the substrate alloy was eroded heavily to a depth of 40-50μm, and surface corrosion products contain NiO, (Ni,Co)(Cr,Al)2O4 spinel and Na(Ta,Nb)O3. Discontinuous oxidation scale generated on the surface of NiCoCrAlYSiB coating while serious internal oxidation appeared throughout the whole coating, and surface corrosion products contain Cr2O3. Dense internal oxidation appeared in the outer layer of the (NiCoCrAlYSiB+AlSiY) coating with a large number of ‘Al depletion area’, and β-(Ni,Co)Al, γ´/γ and Al2O3 existed on the surface of (NiCoCrAlYSiB+AlSiY) coating."
文献类型	学位论文
条目标识符	http://ir.imr.ac.cn/handle/321006/64508
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	卢旭阳. (NiCoCrAlYSiB+AlSiY)复合涂层热腐蚀行为的研究[D]. 北京. 中国科学院金属研究所,2012.