Next Generation of Abradable Coatings for Intermediate Gas Turbine Compressor Stages: Manufacturing Process Development

压气机叶片的叶尖与机匣之间必须有间隙，以避免叶片卡死和损坏。这个间隙通常用可磨（软）涂层密封，以防止空气在使用期间回流到叶片尖端。为了在高压压缩机级（高达500°C）的高温下安全运行，使用固体润滑剂等二级相制造可耐磨涂层矩阵，以减少涂层的材料转移并提高耐磨性。AlSi-hBN是一种极具潜力的金属基-固体润滑涂层材料，其制备方法是等离子喷涂[参考文献]。然而，其耐磨性目前是有限的，主要是由于等离子喷涂工艺无法在涂层中保留足够数量的hBN。该项目旨在确定脉冲气体动态喷涂工艺（PGDS）是否可以用于生产Al-Si+hBN涂层，其性能（微观结构、硬度、附着力、耐磨性）是否符合工业合作伙伴的规范。为了进一步了解PGDS的应用方法、机理及其提高AlSi+hBN涂层耐久性的能力，还需要进行基础研究。

A compressor blade must have a clearance gap between its tip and the engine casing to avoid the blade from seizing and damage. This gap is typically sealed with an abradable (soft) coating to prevent air flowing back over the blade tip during service. To allow safe operation at elevated temperatures typically found in high-pressure compressor stages (up to 500°C), abradable coating matrices are manufactured using secondary phases such as solid lubricants, to minimize the coating's material transfer and promote abradability. AlSi-hBN is a potential metal matrix-solid lubricant coating material successfully manufactured by means of plasma spraying [ref]. However, its abradability is currently limited, mainly due to the inability of the plasma spray process to retain a sufficient amount of hBN in the coating. The proposed project aims at determining if the pulsed gas dynamic spray process (PGDS) can be adapted and developed to produce Al-Si+hBN coatings with properties (microstructure, hardness, adhesion, abradability) meeting the industrial collaborator specifications. Fundamental research is required to increase the understanding of the PGDS application method mechanisms and its ability to improve AlSi+hBN coatings durability.