Session: 18-07 Advanced Turbomachinery Manufacturing - Design, Materials & Processes

Paper Number: 82300

82300 - "FELTMETAL™ Abradable Turbine Seal Materials: Structure and Property Responses to Blade Rub and Oxidation" 

Abradable seals are a common clearance control technology employed to improve turbine engine performance by reducing the gap between the blades and the stationary casing in various turbine stages.  Because operating conditions and material requirements vary significantly as a function of turbine design and stage location, many abradable compositions have been developed and each has its benefits and risks.  This paper describes the unique structure and properties of FELTMETAL^TM abradable materials and discusses how these may correlate to blade wear, heat transfer, seal erosion, and seal oxidation.  Generally, all abradable seal materials employ voids as a designed-defect in their structure to manage thermal and kinetic energy from blade incursion.  Some sealing solutions include non-metallic additives that promote additional sacrificial sealing mechanisms.  The traditional FELTMETAL^TM materials discussed herein are shown to have consistent stable void size and distribution.  During blade incursion, the energy of is mitigated by deforming these voids in the seal.  Recent advances in FELTMETAL^TM materials include non-metallic particles and unique intermetallic phases that further manage blade energy by aiding localized fracture.  FELTMETAL^TM is compared to the structures of other abradable materials, specifically honeycomb and thermal spray coatings, to facilitate discussions of applicability and of future FELTMETAL^TM material design.

Presenting Author: Elaine Motyka Technetics Group

Presenting Author Biography: Elaine Motyka is a Principal Materials Engineer at Technetics Group with expertise in high temperature materials metallurgy, thermal spray coating materials and processes, powder metallurgy, sintering, failure analysis, tribology, and statistical methods for continuous improvement and for new product development. She received her B.S., Mechanical Engineering from Worcester Polytechnic Institute in Worcester MA (1988) and her M.S., Materials Engineering from Rensselaer Polytechnic Institute in Troy NY (1990). Her career has focused on structure-processing-properties relationships to optimize bulk or surface properties for specific applications. These applications covered a range of industries including aerospace and industrial gas turbines, oil & gas, pulp & paper, semi-conductor, and medical orthopedics. At Technetics Group, she contributes to new product and process development, material selection, applications, and materials testing & analysis.

Authors:

Elaine Motyka Technetics Group
Robert Schricker Technetics Group
Kelly Ceiler Technetics Group