【摘要】 采用电子束物理气相沉积(EB-PVD)技术在Ti Al基体上制备Ni Al Hf涂层,结合氧化增重曲线的测试结果,研究了Ni Al Hf涂层对基体在900,950和1000o C空气中氧化行为的影响。采用X-射线衍射(XRD)研究表面的物相结构,XRD结果表明,沉积后表面形成β-Ni Al相,说明Hf固溶于其中。结果表明,在950o C氧化后涂层表面形成致密的氧化铝保护膜。扫描电子显微镜(SEM)和能谱(EDS)被用来测试其表面的形貌和元素分布。结果表明,在氧化过程中,基体和涂层之间的元素发生互扩散。随着氧化时间的增加,涂层厚度减小,扩散区发生显著变化。采用显微硬度表征涂层的韧性,涂层的显微硬度(HV)为7050 MPa左右。Ni Al Hf涂层能提高基体高温抗氧化性能。更多还原

【Abstract】 In order to improve the oxidation resistance of Ti Al substrate at high temperatures, Ni Al Hf coating was prepared by electron beam physical vapor deposition(EB-PVD) on the Ti Al substrate. According to the measured mass gain curves, the effect of Ni Al Hf coating on the oxidation behavior of Ti Al substrate was studied at 900, 950 and 1000 o C. X-ray diffraction(XRD) was employed to identify the phases of the surfaces at different states. The XRD results show that β-Ni Al is formed after deposition and element Hf is found to be dissolved into it. A dense Al2O3 protection film is formed on the coating surface after 950 o C oxidation. Scanning electron morphology(SEM) with energy dispersive spectrum(EDS) was employed to characterize the morphology and element distribution at the cross-section and the surface. During oxidation, elements diffusion occurs at the interface between the substrate and the coating. With increasing of oxidation duration, the thickness of the coating decreases and the diffusion zone changes rapidly. Micro-hardness was used to characterize the coating toughness. Its micro-hardness is about HV7050 MPa. The results show that Ni Al Hf coating can improve the substrate oxidation resistance at high temperatures.更多还原