Abradable coatings (such as Ni-4Cr-4Al/Bentonite) entail a family of coatings used throughout jet engines, primarily as sacrificial coatings into which moving components wear. The coatings generally consist of a metallic phase and a nonmetallic phase, and contain relatively high porosity levels (to 40%). Typical locations for application of an abradable coating include the fan, and low- and high-pressure compressor sections.

The composite nature of abradable coatings presents unique challenges from a metallography standpoint. Due to thickness and porosity considerations, vacuum impregnation with a low-viscosity cold mount epoxy is the recommended mounting method. To facilitate impregnation with fast-cure epoxies (which are typically more viscous than slow-cure epoxies), the resin can be heated to approximately 150°F (65°C) prior to mixing with the hardener. Holding the epoxy at elevated temperature for 15 to 20 minutes should result in a significant improvement in the viscosity of the epoxy.

Source: Doug Puerta, KHA Metallurgical, Portland, Oregon

TSS Regional Events

Aerospace Coatings Symposium
October 15-16 2008
Sheraton Bradley Hotel, Bradley (Connecticut) International Airport
Learn about some of the latest developments in thermal spray and other surface engineering technologies designed specifically for use in the aerospace industry.

Pre-Event Seminar
Materials and Processes for High Temperature Gas Turbine Components
October 13-14, 2008
Sheraton Bradley Airport
Instructor: Dr. Donald Boone, President, BWD Turbines Ltd., Walnut Creek, Calif.
Seminar focuses on thermal spray and other surface modification processes critical to the aerospace industry.

Symposium on Improving Reliability and Consistency in Thermal Spray
December 2-3, 2008
Hyatt Regency Montreal, Quebec, Canada
Presentations by invited speakers covering reliability and consistency of thermal spray processes and coatings, and poster session.

Sponsorships Available for Both Events
To learn more about tabletop exhibiting and sponsorship opportunities, or to discuss customizing a program to meet your specific needs; contact Kelly Thomas, Exposition Sales Manager (440-338-1733)