Gordon England Surface Engineering Forum

Abradable Thermal Spray Coatings

Abradable coatings are designed to preferentially abrade when contact is made with a mating part. Thermal spray abradable coatings have low structural integrity so they are readily abraded when they come into contact with a moving surface with higher structural integrity. The coatings are designed not to damage the mating surface.

There are a number of different abradable coating types, to cater for different operating temperatures, corrosive environments and mating materials. The coating structure can be either:

Aluminium Silicon alloy / Polyester Abradable Coating Microstructure

Plasma sprayed Aluminium Silicon Alloy / Polyester Abradable Coating

The main application of thermal spray abradable coatings is for gas path clearance control in gas turbine engines. In an ideal situation, gas turbine engines would be manufactured with minimal clearance in the gas seal locations, but in the real world these clearances are very much larger to permit operation without catastrophic interaction between rotor and the casing. The clearance at the gas seal locations has a significant effect on the gas turbine engine efficiency which directly translates to fuel consumption. Thermal spray abradable coatings successfully reduce these clearances to a minimum, without the risk of catastrophic failure.

Gas Turbine Engine where abradable coatings play a vital role in operating efficiency

Schematic of a Typical Gas Turbine Engine

These coatings are used in the original manufacture to provide the best possible seals in the first instance. They are also used during overhaul to repair any excessive clearance produced during service. Substantial improvement in engine performance and efficiency can be realised by operating with clearances smaller than those achieved in the original manufacture where abradable coatings were not used.

This technology is now spreading to other applications, such as land based turbines and rotor seals in turbochargers for internal combustion engines.

Thermal spray abradable coatings commonly used in order of increasing temperature capability:






Custom Search

Gordon England Thermal Spray Coating Consultant
Telephone: +44 (0) 1252 405186
Mobile: 07951 120293
Please Click Here to Email
Gordon England Thermal Spray Coating Consultant

THERMAL SPRAY COATING PAGE INDEX

Homepage
Introducing
Nature of Thermal Spray Coatings
Surface Engineering Forum
Surface Engineering in a Nutshell
Thermal Spray Gun Repair Service * Plasma Consumable Parts * Thermal Spray Powder Supplies

Applications: Thermal Spray Coatings on Carbon and Glass Fibre Reinforced Polymers * HVOF Coating of Paper Making Roll * Abradable Coatings *

Photomicrographs: Plasma Sprayed Coatings * Plasma Sprayed Chromium Oxide Coatings * Plasma Sprayed Chromium Oxide Coatings 2 * Combustion Sprayed Coatings * HVOF WC/Co Thermal Spray Coatings * HVOF WC/CoCr Thermal Spray Coatings * HVOF WC/CrNi Thermal Spray Coatings * HVOF NiCrMo (625) Thermal Spray Coatings * HVOF NiCrMoWFe (Hastelloy C) Thermal Spray Coatings * HVOF Chromium Carbide Thermal Spray Coatings * Plasma Sprayed WC/Co Coatings * WC/NiCrBSi Thermal Spray Coatings * Thermal Spray Coatings Rogues Gallery * Thermal Spray Coatings Rogues Gallery 2 * Thermal Spray Coatings on Composite Substrates * Thermal Spray Coatings on Composite Substrates 2 * Effect of Metallographic Preparation Technique on Thermal Spray Coatings * Effect of Thermal Spray Coating Process and Powder Size 1 * Effect of Thermal Spray Process and Powder Size 2 * Thermal Spray Abradable Coatings * Combustion Wire Sprayed Coatings * Arc Sprayed Coatings * Arc Sprayed Coatings 2 * Thermal Spray Ceramic Coatings * HVOF Self-fluxing NiCrBSi Coating (not fused) *

Thermal Spray Processes: Combustion Wire Thermal Spray Process * Combustion Powder Thermal Spray Process * Arc Wire Thermal Spray Process * Plasma Thermal Spray Process * HVOF Thermal Spray Process * Detonation Thermal Spray Process * Plasma Flame Theory * Cold Spray Coating Process *

Wear and Thermal Spray Coatings
Corrosion and Thermal Spray Coatings
Glossary of Thermal Spray and Surface Engineering Terms
Image Directory for Thermal Spray Coatings
Plasma Gas Flow Information
Plasma Gas Flow Correction Calculator
Contact Form
Links to other interesting sites related to thermal spray and surface engineering * Reciprocal Links

Periodic Table of the Elements
SI Units * Calculators for Conversion between Units of Measurement
Hardness Testing
Surface Engineering Message Board Archive
Surface Engineering Message Board Archive Index
Search This Site
Photography Gallery


© Copyright Gordon England