电压对TC4钛合金表面微弧氧化膜层红外发射率的影响

摘要

Ceramic coatings were fabricated on TC4 titanium alloys by micro-arc oxidation(MAO) technique in the mixed silicate,phosphate and KMnO4electrolytes with different voltages. The properties of the MAO coatings on TC4 titanium alloy surfaces were studied. The microstructure,phase and chemical composition were characterized by scanning electron microscope,X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS) and infrared emissivity of the MAO coatings was measured by fourier transform infrared spectroscopy. The results show that with the increase of voltage,the thick-ness,roughness and infrared emissivity of the coatings steadily increase, the characteristic peaks of TiO2and Ti decrease gradually which indicates the amorphous phase becomes the main component. It can be concluded that elements Si,P and Mn exist as the amorphous state in the coatings based on the XRD and XPS results. The infrared emissivity increases greatly and reaches the maximum at 540 V and an average of up to 0.84 is observed in 8 μm to 20 μm band.%在硅酸盐、磷酸盐及高锰酸钾的混合电解液中研究了不同电压对TC4钛合金微弧氧化膜层性能的影响,通过扫描电镜(SEM)、X射线衍射(XRD)和X射线光电子能谱(XPS)分析了膜层的微观形貌、相组成及化学成分,用傅里叶变换红外光谱仪测试了样品的红外发射率.结果表明,随着电压的升高,膜层的厚度、粗糙度及红外发射率持续增加,膜层中TiO2与Ti的特征峰逐渐减弱,非晶相成为主要的组成部分.结合XRD与XPS分析结果可推断膜层中主要元素Si、P、Mn均以非晶态存在.当电压为540 V时膜层发射率有较大幅度的增加并达到最大,在8~20 μm的波段范围内平均发射率可达0.84.