M. R. Dorfman, L. Xie, S. Wilson, Sulzer Metco (US) Inc., Westbury, NY; D. R. Sporer, Sulzer Metco (Canada) Inc., Sonthofen, Germany
Abradable seals have been used in jet engines since the late 1960's. Today abradable seals are seeing applications not only in low pressure and high pressure section of the compressor but in the HP turbine section, and are gaining more attention in industrial gas turbines. Thermal spraying is a relatively simple and cost effective means to reduce gas path tip clearance. Reduced tip clearance implies improved engine efficiency and power output. Types of coatings are zirconia based ceramic abradable systems with polymer and in some cases hBN additions and can see service temperatures of up to 1150 ºC . The objective of this paper will be to review the type of ceramic abradable coating systems used and their overall customer benefits. Yttria stabilized zirconia based abradables will be reviewed as well as the role of alternative stabilizers such as dysprosium oxide and ytterbium oxide and the impact they have on high temperature sintering and mechanical properties. The impact of porosity on abradability and erosion resistance will be discussed.
Summary: Processing and Properties of Advanced Ceramic
Abradable seals have been used in jet engines since the late 1960's. Today abradable seals are seeing applications not only in low pressure and high pressure section of the compressor but in the HP turbine section, and are gaining more attention in industrial gas turbines. Thermal spraying is a relatively simple and cost effective means to reduce gas path tip clearance. Reduced tip clearance implies improved engine efficiency and power output. Types of coatings are zirconia based ceramic abradable systems with polymer and in some cases hBN additions and can see service temperatures of up to 1150 ºC . The objective of this paper will be to review the type of ceramic abradable coating systems used and their overall customer benefits. Yttria stabilized zirconia based abradables will be reviewed as well as the role of alternative stabilizers such as dysprosium oxide and ytterbium oxide and the impact they have on high temperature sintering and mechanical properties. The impact of porosity on abradability and erosion resistance will be discussed.
