DZ125合金真空电弧镀沉积复合涂层技术

采用真空电弧镀技术(arc ion plating,AIP)在DZ125定向高温合金基体上制备60μm沉积-扩散型复合涂层(NiCrAlYSi+AlYSi)。通过扫描电镜(SEM)、X射线衍射分析涂层的组织及结构,涂层外层形成大量的β-NiAl相,涂层中Al浓度自外向内逐渐降低,形成具有浓度梯度的复合涂层,有利于高温下涂层表面形成致密的Al2O3保护膜,提高表面保护膜的自愈能力。对沉积-扩散型复合涂层的试样进行1150℃抗氧化实验和900℃抗热腐蚀等实验,评价其抗氧化、抗腐蚀性能,对涂层氧化速率及腐蚀速率进行表征。结果表明:复合涂层明显改善了合金的抗高温氧化性能,承温能力明显提高,寿命延长。

AIP multi-layer coating on DZ125 superalloy substrate

The deposited-diffusion multi-layer coating(NiCrAlYSi + AlYSi) on top of DZ125 superalloy substrate with the thickness of 60 μm was fabricated by arc ion plating(AIP). The morphology and phase structure of the coating were analyzed by scanning electron microscope(SEM) and X-ray diffraction(XRD), respectively. It was found that a lot of β-NiAl phases were formed on the outer layer of the coating. The content of Al element contained in the coating was gradually decreased from the outer layer to the inner layer, and a multi-layer coating with a concentration gradient was formed. This phenomenon was good for forming a dense Al2 O3 scale on the surface of the coating at high temperature and further improving the self-healing ability of the scale. The oxidation behavior and hot corrosion performance of the coating samples were tested at the temperature of 1150 ℃ and 900 ℃,respectively. The experimental results show that the oxidation-resistant performance of the superalloy substrate is obviously improved in combination of multi-layer coating. Meanwhile, the service temperature and lifetime of the substrate have been effectively improved.