钛合金用Ti_(0.75)Al_(0.25)N防护涂层的制备与抗氧化性能

Preparation and oxidation resistance of Ti_(0.75)Al_(0.25)N coatings deposited on titanium alloy

采用真空电弧离子镀技术在TC11钛合金基片上制备Ti0.75Al0.25N防护涂层,并用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、俄歇能谱分析仪(AES)、X射线光电子能谱(XPS)等方法研究了涂层在空气中650～800℃范围内的热防护性能。结果表明,在给定的温度范围内,涂层可有效降低合金的氧化增重;XPS分析表明,表层富Al氧化物以α-Al2O3的形式存在;AES深度分析表明,元素的扩散出现台阶状分布,外层富Al、O,内层富Ti、N,高温氧化时,Al的选择性氧化形成致密的Al2O3层可以阻止基体与外界氧介质的通道,这是涂层防护钛合金具有良好高温性能的原因。

Ti0.75Al0.25N coatings were deposited on TC11 alloy sheets by vacuum arc ion plating technique.Thermal protective performance of the coatings from 650 ℃to 800 ℃ in air was investigated by scanning electron microscopy（SEM）,X-ray diffraction（XRD）,auger electron spectroscopy（AES）,and X-ray photoelectron microscopy（XPS）.The results indicate that the oxidation weight gain of the coated samples can be reduced effectively in the limited temperature.Al-rich oxides at the surface layer are characterized by α-Al2O3based on XPS results.AES depth profile shows that the diffusion distribution of the Ti0.75Al0.25N coatings emerges a step shape.There were accumulations of Al and O element on the surface,while Ti and N enriched in the internal layer.The selected oxidation of aluminum forming compact Al2O3layer can impede the diffusion channel of O element,which improve the high temperature performance of the titanium alloy.