电弧离子镀NiCoCrAlYTa涂层制备及其高温防护性能研究

Preparation and High Temperature Protection Performance of NiCoCrAlYTa Coating by Arc Ion Plating

为进一步提升高温合金材料的服役性能,利用真空阴极电弧离子镀技术在DZ22B高温合金上沉积NiCoCrAlYTa涂层,研究涂层对基材力学性能的影响和高温性能等。采用扫描电镜观察膜层表面和截面形貌,用X射线衍射仪分析涂层的物相组成,用万能试验机检测室温拉伸性能和高温光滑持久强度性能。结果表明:所沉积的NiCoCrAlYTa涂层厚度达60μm以上,经热处理后,涂层更加致密且与基体因互扩散实现了冶金结合;NiCoCrAlYTa涂层的相组织主要为γ′-Ni3Al/γ-Ni。表面沉积NiCoCrAlYTa涂层后,对DZ22B基材的室温拉伸性能和高温光滑持久强度性能虽稍有影响,但均能满足应用的要求。在1050℃高温下,NiCoCrAlYTa涂层表面形成了一层致密的氧化层,从而减缓了氧化速度,其氧化速度仅为DZ22B基材的50%;DZ22B基材表面沉积NiCoCrAlYTa涂层后,抗950℃燃气热腐蚀能力提高了225倍。

In order to improve the service performance of superalloy,NiCoCrAlYTa coatings were deposited on DZ22B superalloy by cathode arc ion plating.Scanning electron microscopy was used to observe the surface and section morphology of the coatings,X-ray diffraction was used to analyze the phase composition of the coating,The tensile strength at room temperature was tested by universal testing machine,and the high temperature endurance strength was tested by high temperature durability testing machine.The results show that the thickness of NiCoCrAlYTa coating is more than 60μm,After heat treatment,the coating is more compact,and metallurgical bonding is obtained between the coating and the substrate due to element diffusion.The phase structure of NiCoCrAlYTa coating is mainly composed ofγ′-Ni3Al/γ-Ni.NiCoCrAlYTa coating has little effect on the room temperature tensile properties and high temperature smooth endurance properties of DZ22B substrate,but it can meet the application requirements.At 1050℃,a dense oxide layer was formed on the surface of NiCoCrAlYTa coating,which slows down the oxidation rate.The oxidation rate of the coating is half of DZ22B substrate.After coated with NiCoCrAlYTa coating of DZ22B substrate,the resistance of gas hot-corrosion at 950℃was increased by 225 times.