Water erosion resistant surface treatments

在压缩机中注入水来冷却空气，从而增加燃气轮机的功率输出是一种常见的做法。水滴的反复撞击可能会导致翼型前缘的严重侵蚀，不仅导致性能下降，而且还可能由于气动不稳定性而导致翼型的高周疲劳失效。因此，需要开发一种更耐水蚀的压气机叶片。该项目将包括不同材料的水蚀机理的研究，耐水蚀涂料的开发，这些涂料的表征和测试。它还将包括对水冲击现象进行建模。不同大小的水滴在局部撞击表面时提供不同的动能，因此防护涂层应该坚硬、坚韧并具有疏水效果。将研究各种涂层，包括硬质纳米结构陶瓷涂层和疏水涂层。将对所开发的涂层的微观结构、力学性能和功能性能进行研究。这将包括研究衬底条件(即微结构、织构和残余应力)对所得涂层/表面处理的微结构、性能和耐蚀性的影响。耐蚀性测试将在根据ASTM G73-04标准(液体撞击侵蚀测试的标准实践)设计的特殊试验台上进行，并进行调整以模拟压缩机内部的运行条件。在该试验台中，可以确定材料和涂层/表面处理的抗侵蚀或其他损伤；研究损伤机制以及水滴的大小、速度和频率对其的影响。通过这种方式，我们将能够研究叶片材料的水蚀行为和动态力学性能之间可能的相互作用。

Injecting water to cool the air in the compressor hence increasing the power output of the gas turbines is a common practice. Repeated impacts of water droplets maycause significant erosion along the leading edges of the airfoils resulting not onlyin performance degradation but also in potential for high-cycle fatigue failure of the airfoils due to aerodynamic instability. Consequently, there is a need to develop a more water erosion resistant compressor blades. This project will include the studyof water erosion mechanism of different materials, development of coatings resistant to water erosion, characterization and testing of these coatings. It will also include modeling of the water impingement phenomenon. Different sizes of water droplets provide various kinetic energywhile locally hitting the surface, thus protective coatings should be hard, tough and provide the hydrophobic effect. Various coatings will be studied including hard nanostructure ceramic and hydrophobic coatings. The microstructure, mechanical and functional properties of the developed coatings will be studied. This will include the investigation of the effect of substrate conditions (i.e. microstructure, texture and residual stresses) on the microstructure, properties and erosion resistance of the resulting coating/surface treatment. Testing of erosion resistance will be performed on a special rig designed as per ASTM G73-04 standard (Standard Practice for Liquid Impingement Erosion Testing) and adjusted to simulate the operating conditions inside the compressor. Inthis test rig, it will be possible to determine the resistance to erosion or other damage of the materials and coatings/surface treatments; to investigate the damage mechanisms and how theyare influenced bythe size, velocityand frequencyof water droplets. In this way, we will be able to studya possible interaction between water erosion behaviour and dynamic mechanical properties of the blades materials.