An experimental study of the high speed interaction between a labyrinth seal and an abradable coating in a turbo-engine application

• Published in: Wear 2014-08, Vol.316 (1-2), p.109-118
• Main Authors: Delebarre, C., Wagner, V., Paris, J.Y., Dessein, G., Denape, J., Gurt-Santanach, J.
• Format: Article
• Language: English
• Subjects: Abrasion; Aluminum; Assessments; Coating; Engineering Sciences; Exact sciences and technology; Fundamental areas of phenomenology (including applications); High speed; High speed interaction; Labyrinth seal; Labyrinth seals; Materials; Mechanical contact (friction...); Nickel base alloys; Physics; Solid mechanics; Structural and continuum mechanics; Superalloys; Teeth; Thermal expansion; Thermal spray coatings
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/j.wear.2014.04.023

A new high-speed test rig was designed to simulate the interactions between labyrinth seals and abradable coatings in similar turbo-engine operating conditions. To determine a solution for turbo-engine efficiency enhancement, we investigated the clearance reduction between the rotary parts in air systems, the successive starts and stops, the thermal expansion and the vibrations that might cause direct rub interactions between a rotary seal, known as a labyrinth seal, and a turbo-engine housing coated with a sacrificial abradable material. High interaction speeds from 0 to 130ms−1 were obtained using a 5-axis milling machine fitted with a unique magnetic bearings spindle developed specifically for the study. The purpose of this paper is to study the interaction phenomena between an abradable material (Al–Si 6%) and a nickel alloy (Alloy 718) to obtain a first contact assessment under different turbo-engine operating conditions. The experimental results are first presented by visual observations of the posttest samples, as specified by accurate profile measurements. A quantitative approach to the interaction forces recorded during the tests and micrographic observations complete the preliminary study. This work provides new basic data for a preliminary study of the interaction between labyrinth seal teeth tips and abradable coatings in turbo-engine applications. •High speed test rig designed and developed to simulate labyrinth seal–abradable interactions.•Contact assessment between Al–Si 6% and Alloy 718 under turbo-engine operational conditions.•Results presented by visual observations, interaction forces analysis and micrographic examinations.•New basic data for a preliminary study of labyrinth seal teeth and abradable coating.