Respected Members

can somebody tell me about the future trend in abradable coatings according to application technique and material point of view.

Regards

wasif

Hi wasif

I would imagine continued development of high temperature abradable coatings to meet increasing temperatures of gas turbine engines. Economic abradable coatings for non-aero applications like automotive turbochargers. Increase use of HVOF/HVAF/cold spray processes.

Mr Gordon,

Would you please mention about high temperature abradable coatings applications (materials, alloys, specifications)? I found plasma sprayed abradable coatings on your "Thermal Spray Coating Page Index - http://www.gordonengland.co.uk/pmg13.htm" and some HVOF abradable coatings on "www.azom.com"

I also want to learn if it is possible that producing a composite coating such as combining layers in order to Bond Coat, TBC, abradable (top layer) etc.

Regards,

Nurettin

Hi wasif & Nurettin

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

* Aluminium silicon alloy/polymer composites
* Aluminium silicon alloy/graphite composites
* Nickel/graphite composites
* Aluminium bronze/polymer composites
* Nickel chromium aluminium/boron nitride composites
* Nickel chromium aluminium/bentonite composites
* Nickel/aluminium composite sprayed porous
* Nickel chromium aluminium composite sprayed porous
* MCrAlY/BN/Polyester composites
* YSZ ceramic/Polyester composites

A few links if you havn't seen them already:

Abradable Coatings

AZOM - Abradable Coatings Increase Gas Turbine Engine Efficiency

Sermatech - abradable coating pdf

The-Black-Art-of-Abradable-Coatings

high temp abradable development

another pdf

Quote:I also want to learn if it is possible that producing a composite coating such as combining layers in order to Bond Coat, TBC, abradable (top layer) etc.

The very high temperature abradable coatings (YSZ ceramic) I would expect to be good TBC as well . Multilayer and gradated coatings would certainly be possible if those properties were desired.

Mr Gordon,

Thanks for these useful links, information and documents.
I'll continue on my research of Self Healing TBCs and High Temperature Abradable Coatings for Gas Turbine Engines, then multilayer or gradated TBC & Abradable Coating is a good idea.

Regards,