GH738合金表面Al-Si渗层的制备及其抗氧化行为  

Preparation and oxidation resistance of Al-Si coating on GH738 alloy

作　　者：郭孟鑫 冉雪林 张进[1] Guo Mengxin;Ran Xuelin;Zhang Jin(School of New Energy and Materials,Southwest Petroleum University,Chengdu Sichuan 610500,China)

机构地区：[1]西南石油大学新能源与材料学院,四川成都610500

出　　处：《金属热处理》2023年第3期188-194,共7页Heat Treatment of Metals

基　　金：长寿命高温材料国家重点试验室开放课题(DTCC28EE200794)。

摘　　要：采用热扩散法在GH738合金表面制备出Al-Si渗层。通过X射线衍射仪(XRD),扫描电镜(SEM),能谱仪(EDS)分析了Al-Si渗层形貌、厚度、物相组成和元素分布;采用显微维氏硬度计测定了渗层的硬度;采用静态增量试验方法,在1200℃,对Al-Si渗层试样和GH738镍基合金基体进行了100 h的恒温抗氧化性能测试。结果表明,Al-Si渗层厚度可达120μm,渗层为明显的双层结构,外层为Al-Si层,内层为互扩散层;渗层物相组成主要为NiAl和Ni_(2)Al_(3)以及少量Cr3Si;渗层表面硬度达到900 HV0.1左右,约为基体的3.5倍;Al-Si渗层氧化动力学曲线满足抛物线规律,氧化速率常数为0.0987 mg^(2)·cm^(-4)·h^(-1),表面形成比较致密的Al2O3保护膜,其高温抗氧化性能较基体提高了约5倍。Al-Si coating was prepared on the surface of GH738 alloy by thermal diffusion method.The morphology,thickness,phase composition and element distribution of the Al-Si coating were studied by means of X-ray diffraction(XRD),scanning electron microscope(SEM)and energy dispersive spectrometer(EDS);the hardness of the coating was determined by hardness tester;the static high temperature oxidation resistance test was carried out at 1200℃for 100 h.The results show that the coating thickness reaches 120μm,the coating is an obvious double-layer structure,the outer layer is Al-Si layer,and the inner layer is inter-diffusion layer;the phase composition of the coating is mainly NiAl and Ni_(2)Al_(3)with a small amount of Cr3Si;the hardness of the coating reaches about 900 HV0.1,which is about 3.5 times of the matrix;the oxidation kinetics curve of the coating meets the parabolic law,and the oxidation rate constant is 0.0987 mg^(2)·cm^(-4)·h^(-1).The high temperature oxidation resistance of the relatively dense Al2O3 protective film formed on the alloy surface is about 5 times higher than that of the matrix.

关 键 词：GH738合金 热扩散法 Al-Si渗层 高温抗氧化性 

分 类 号：TB31[一般工业技术—材料科学与工程]