关键词: 可磨耗封严涂层, 冲蚀磨损, 机理, 模型

Abstract:

The erosion wear resistance is one of the most important properties of abradable seal coating. The erosion wear behaviour and mechanism of several kinds of middle temperature abradable seal coatings were investigated by a CMS 100 self made vacuum sand erosion machine. The results show that the relationship between the erosion weight loss and the erosion time is linear, the coatings hold a maximum erosion rate at 60° impact angle, and the relation between the erosion rate and the impact speed is an exponential function. The speed exponent increases with the increase of the impact angle. At 90° impact, the abrasive particles impinging on the coating surface produce indents and extrude lips, then the lips are work hardened and fall off; and flattened metal phase grains are impinged repeatedly, loosen and exfoliate. At 30° impact, the micro cutting, plowing and tunneling via pores and non metal phase are involved. The model of the erosion mechanism is advanced on the basis of the above mentioned erosion behaviour.

Key words: abradable seal coat ing, ero sion w ear, mechanism, models