适用于涡轮叶片硬质颗粒冲蚀保护的磁控溅射厚氮化物层及纳米复合镀层研究

Solid Particle Erosion Protection of Turbine Blades with Thick Nitride and Nanocomposite Coatings from Magnetron Sputter Deposition

硬质颗粒冲蚀（SPE）是固定式压缩机叶片和风煤气涡轮叶片失效的主要机制，冲蚀不仅降低了涡轮的效率，还减少了其使用寿命。从而，降低了可靠性和有效性，增加了涡轮运行的总成本。在沙漠环境下，SPE尤为严重，甚至会导致事故。为此，提出采用等离子增强磁控溅射技术（PEMS）制备厚氮化物层（TiN，CrN，ZrN）和纳米复合碳氮化物镀层，来解决此类问题。该技术结合了传统磁控溅射和专门产生的等离子体，以获得更高的电流密度。在沉积前和沉积过程中采用重离子轰击的方法，能够有效提高涂层的结合力，并限制柱状组织生长，使得单层的TiN，CrN，及ZrN氮化物层厚度可达80μm，TiSiCN，ZrSiCN碳氮化物层厚度也可达30grn。试样分为两组进行了冲蚀试验，结果表明，TiSiCN镀层表现出了最优异的抗冲蚀性，是裸露不锈钢及Ti-6Al-4V基体的25倍，是其它氮化物层的5-10倍。文中将讨论沉积工艺，通过扫描电镜（SEM），能谱分析仪（EDX），透射电镜（TEM）及x射线衍射仪（XRD）研究镀层微观组织结构，通过纳米压痕试验测试镀层的纳米硬度，进行冲蚀试验测试镀层的耐冲蚀性能。此项技术不仅适用于保护先进的飞机系统中涡轮压缩叶片、轮叶、转子叶片等，同样适用于重载柴油机的液压泵轮及活塞环。

Solid particle erosion （SPE） damage is a major degradation mechanism for compressor blades of land-based and air gas turbine engines. Not only does erosion reduce the efficiency of the turbines, but it also reduces the service lifetime, thereby reducing the reliability and availability and increasing the overall cost of turbine operation. In desert environments, SPE becomes even more severe and it can lead to the loss of life. To combat erosion thick nitrides （TIN, CrN and ZrN） and nanocomposite carbonitrides （TiSiCN and ZrSiCN） have been deposited using a Plasma Enhanced Magnetron Sputtering （PEMS） technique. The technique combines conventional magnetron sputtering and externally generated plasma from which high current density can be obtained. By using heavy ion bombardment prior to and during deposition to increase the coating adhesion and limit columnar growth, single-layered thick nitrides of TiN, CrN, and ZrN coatings up to 80 micrometers and thick carbonitride coatings of TiSiCN and ZrSiCN up to 30 micrometers have been obtained. Test coupon samples have been subjected to two independent erosion tests. It has been observed that TiSiCN renders the best erosion resistance - nearly 25 times lower than the uncoated stainless steel or Ti-6Al-4V and about 5-10 times lower than all other nitrides. In this paper, we will discuss the deposition technology and the coating microstructure studied using Scanning Electron Microscopy （SEM） with Energy Dispersive X-ray analysis （EDX）, Transmission Electron Microscopy （TEM）, and X-Ray Diffractometry （XRD）. We will present the nano-hardness results from the nanoindentation tests and erosion resistance from the erosion tests. The technology may be applied to protect turbine engine compressor blades, vanes and rotor blades in advanced aircraft and fluid pump impellers as well as piston rings for heavy-duty diesel engines.