Suspension plasma sprayed thermal barrier coatings on ODS bond coats
Suspension plasma sprayed thermal barrier coatings on ODS bond coats
Monday, May 24, 2021: 8:00 AM
Suspension plasma spraying is an attractive technology to produce columnar, strain tolerant thermal barrier coatings. In the past, it has been observed that the lifetime of the coatings especially in harsh burner rig conditions is not always as good as expected. It is believed that this is related to the specific manufacturing process. Based on this knowledge different strategies to improve the performance of SPS TBCs have been developed which will be presented.
The first measure is the use of flat substrates which led to some increase of the thermal cyclic life. A further, very efficient way to improve the SPS systems is the use of an APS interlayer. The coatings show largely improved lifetimes better than APS coatings. A third measure is the use of oxide dispersion strengthened (ODS) bond coats. Depending on the amount of oxide addition, alumina was used, different results could be obtained. The addition of 10 wt.-% alumina gave the best performance. These results will be explained also by a microstructural analysis of the failed coatings systems.
The first measure is the use of flat substrates which led to some increase of the thermal cyclic life. A further, very efficient way to improve the SPS systems is the use of an APS interlayer. The coatings show largely improved lifetimes better than APS coatings. A third measure is the use of oxide dispersion strengthened (ODS) bond coats. Depending on the amount of oxide addition, alumina was used, different results could be obtained. The addition of 10 wt.-% alumina gave the best performance. These results will be explained also by a microstructural analysis of the failed coatings systems.