Cerca nel sito per parola chiave

pubblicazioni - Poster

Laser flash and thermographic techniques: analysis of testing parameters models and microstructure

pubblicazioni - Poster

Laser flash and thermographic techniques: analysis of testing parameters models and microstructure

Verranno presentate tecniche fototermiche e termografiche in grado di eseguire la caratterizzazione termo-fisica e la valutazione non distruttiva dell’integrità del TBC.

Since several years, photothermal and thermographic techniques have been used to perform the thermo-physical characterisation of TBCs and the non-destructive assessment of TBC integrity. The description of a thermographic technique able to simultaneously measure the through-the-thickness and the in-plane thermal diffusivity of free standing TBCs samples and thus giving evidence of the typical microstructural anisotropy of APS TBCs will be provided A theoretical and experimental analysis of the real capabilities of infrared techniques to estimate the porosity content and the microstructure of porous ceramic materials such as TBCs by studying thermal diffusivity variations when pores are filled with air or vacuum will be provided The method for the semi-quantitative estimation of the interface cracked fraction between the bondcoat and TBC, within coupons subjected to thermal cycling, will be proposed. It consists on the evaluation of the TBC thermal diffusivity evolution during ageing compared to the as sprayed value. 

A critical analysis, starting from the contradictory results obtained applying this method on several sets of APS TBC samples, complements the topic. A successful case of integrating the aforementioned approach with the apparent thermal effusivity method to monitor damage progression of Bondcoat-TBC interface over thermal cyclic oxidation tests will be presented together with the comparison with computed tomography images of the same samples.

Progetti

Commenti