link to homepage

Institute of Energy and Climate Research

Navigation and service

Assessment of high-temperature protective coatings

An increasingly important aspect of the application at even higher temperatures is the resistance of porous layers to calcium-magnesium-aluminium silicates (CMAS) penetrating into them. These silicates are present in air as solids and are also produced by abrasion in the hot gas path. They are deposited on the turbine components and can penetrate the thermal barrier coatings in their melted form. Once they solidify, they cause considerable damage by decreasing the strain tolerance. In addition to the Gd-containing pyrochlores, aluminates also show a better stability than YSZ.

WDS: Testing thermal barrier coatings

Testing thermal barrier coatings under realistic conditions with CMAS deposits (left). Micrographs (cross-section) of the typical open pore structure of YSZ APS TBC partially infiltrated by molten CMAS deposit.

In order to ensure fast development cycles, the functionality and lifetime of these novel thermal barrier coatings are tested in standard specimens as well as in parts with complex geometries at high temperatures in realistic cycling tests.