采用CVD法制备空心叶片内腔铝化物涂层

Preparation of aluminide coating on hollow-blade inner-cavity by CVD method

采用自主研制的化学气相沉积(Chemical vapor deposition,CVD)内腔铝化物涂层设备及工艺在空心叶片内腔微小冷却通道制备了铝化物涂层。借助金相显微镜(OM)、扫描电镜(SEM)、能谱仪(EDS)、X射线衍射(XRD)等方法分析了空心叶片内腔及微小冷却通道不同部位的涂层厚度以及涂层的表面形貌、元素成分和相组成。结果表明:自主研制的CVD内腔渗铝设备及工艺可靠,涂层厚度达33～39μm,内腔涂层完整均匀,不存在漏渗;涂层主要分为内外两层,外层主要由β-Ni Al相组成,Al含量为26. 85wt%,对基体可以进行有效地防护,具有广阔的工程化应用前景。

Aluminide coatings were prepared on the surface of internal cooling channel in turbine blade by chemical vapor deposition( CVD)method.The aluminide coatings were characterized by means of metallographic microscope,SEM,EDS and XRD.The results indicate that the self-developed CVD aluminizing equipment and process are reliable.The thickness of the aluminide coating is 33-39 μm,the aluminide coating on the surface of internal cooling channel is complete,homogeneous,and no leakage.The coating consists mainly of the outer layer and the inner layer.The outer layer is mainly composed of β-Ni Al phase,and the Al content is 26.85 wt%.The coating can effectively protect the surface of internal cooling channel in turbine blade,and has broad engineering application prospects.