摘要
在镍基高温合金Inconel 718表面采用电镀的方法沉积不同厚度的Pt镀层,然后采用化学气相沉积(CVD,chemical vapor deposition)的方法,分别制备了单一铝化物涂层、β-(Ni,Pt) Al涂层和PtAl2+β-(Ni,Pt) Al双相涂层,其中单一铝化物涂层和β-(Ni,Pt) Al涂层为双层结构,外层为β相,内层为互扩散区;PtAl2+β-(Ni,Pt) Al双相涂层为3层结构,外层由β相和弥散分布的PtAl2组成,中间层为β相,内层为互扩散区。对3种涂层在900℃下95%Na2SO4+5%NaCl混合盐(质量分数)中进行热腐蚀试验,结果表明,Pt镀层为6μm的β-(Ni,Pt) Al涂层表现出较好的抗热腐蚀性能,而Pt镀层增加到12μm的PtAl2+β-(Ni,Pt) Al双相涂层的抗热腐蚀性能有所下降,主要原因是其表面皱曲程度较大引起的氧化膜剥落。Pt的加入增强了表面保护性氧化膜的黏附性,且提高了氧化膜的致密度。所制备的Pt-Al涂层对基体合金可以进行有效地防护,具有广阔的工程化应用前景。
Pt plating layers with various thicknesses were prepared on the surface of Inconel 718 Ni-based superalloy by electroplating method,and then chemical vapor deposition(CVD)was employed to synthesize single aluminide coating,β-(Ni,Pt)Al coating and PtAl2+β-(Ni,Pt)Al dual-phase coating.Among them,the single aluminide coating andβ-(Ni,Pt)Al coating had the double-layer structure.The out layer wasβphase and the inner layer was inter-diffusion phase,respectively.PtAl2+β-(Ni,Pt)Al had the three-layer structure.The outer layer wasβphase and PtAl2,and the middle layer wasβphase,as well as the inner layer was inter-diffusion phase.Furthermore,hot corrosion tests were carried out on the three kinds of coatings at 900℃in 95%Na2SO4+5%NaCl solution.Result showed that theβ-(Ni,Pt)Al coating with a Pt layer of 6μm presented superior hot corrosion resistance.When the thickness of Pt plating layer increased to 12μm,the hot corrosion resistance of PtAl2+β-(Ni,Pt)Al double-phase coating decreased,and the main reason was the spallation of the oxide film caused by the large degree of surface rumpling.In general,the addition of Pt enhanced the adhesion of the surface protective oxide film and improved the density of oxide film.Pt-Al coating prepared in this work could protect the alloy substrate effectively,which presented broad prospects for engineering application.
作者
张磊
吴勇
夏思瑶
张博闻
ZHANG Lei;WU Yong;XIA Si-yao;ZHANG Bo-wen(Wuhan Research Institute of Materials Protection-State Key Laboratory of Special Surface Protection Materials and Application Technology,Wuhan 430030,China)
出处
《材料保护》
CAS
CSCD
北大核心
2020年第3期1-7,共7页
Materials Protection
基金
国家科技重大专项“先进成形与焊接共性关键技术创新能力平台建设”(2018ZX040440011001)资助。
关键词
化学气相沉积
电镀Pt
镍基高温合金
Pt改性铝化物涂层
热腐蚀
chemical vapor deposition
Pt plating
nickel-based superalloy
Pt-modified aluminide coatings
hot corrosion
