Influence of porosity characteristics in MgO.ZrO2-GG coating subjected to thermal loading

✍ Scribed by A. Mimaroglu; U. Kocabicak; S. Genc

• Publisher: Elsevier Science
• Year: 1997
• Weight: 607 KB
• Volume: 18
• Category: Article
• ISSN: 0261-3069
• DOI: 10.1016/s0261-3069(97)00042-3

✦ Synopsis

In this investigation, coupled (thermal and structure) finite-element analysis has been employed to analyse the influences of porosity volume, size and distribution in MgO.ZrO,-GG coating subjected to thermal loading. Coatings with and without NiAl interlayer material were modeled. All models had a 1 /IO coating-to-substrate thickness ratio and a porosity ratio of 3% and 7%. The porosity location and distribution were also considered and modeled. Thermal stresses at the vulnerable areas (film/ substrate) were obtained and compared. The results showed that the volume, size, location and distribution of the porosity have a significant influence on the level of the developed thermal stresses. In the case of MgO.ZrO,-GG coatings the optimum low-level stresses are developed with 7% small-size uniformly-distributed porosity allocated far away from the coating surface.