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

压缩机叶片的尖端和发动机机壳之间必须有间隙，以避免叶片卡住和损坏。这种间隙通常是用可磨损(软)涂层密封的，以防止空气在使用过程中从叶片尖端回流。为了在高压压缩机级(最高可达500°C)的高温下安全运行，使用第二相(如固体润滑剂)制造可磨损涂层基质，以最大限度地减少涂层的材料转移并提高耐磨性。AlSi-hBN是一种很有潜力的等离子喷涂金属基-固体润滑涂层材料。然而，其耐磨性目前是有限的，主要是由于等离子喷涂过程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力喷涂工艺(PGDS)是否适用和发展，以生产出组织、硬度、附着力、耐磨性等性能满足合作者要求的Al-Si+hBN涂层。需要进行基础研究，以增加对PGDS应用方法、机理及其提高AlSi+hBN涂层耐久性的能力的了解。

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.