Thermal Barrier Coatings (Case Study) By Keepsake Engineering Consultancy Pvt. Ltd.

Thermal Barrier Coatings (Case Study)The barrier coat reduces the direct effect of temperature by reducing heat transfer caused by conduction, convection & radiation. Thus the base material retains properties which it could have lost at high temperature exposure. The final coating material is normally a ceramic oxide. Industry uses are mostly limited to Stabilized zirconia( Zirconia changes phase at around 1000 deg C) or Alumina. All ceramic oxides are oxygen transparent hence a oxidation resistant bond coat is provided. Coatings can peel off at high temperature due to variation in co-efficient in thermal expansion. Hence depending on base material a graded CTE matched material is applied. We have carried out repairs on Roof jackets of copper blast furnace. The jackets had following propertiesMOC copper. Wear due to high temperature corrosion by SO4 gases and splashing of molten copper on roof jackets at 1240 deg C. observed wear was around 15-20mm reduction in thickness of copper jacket. The jackets are water cooled. Solution: Multi layer coatings of bond coat + top coat + sealant are applied. We carried out the job by ARC spray Aluminium bronze + MCRAlY alloy + Rod sprayed Alumina + Sealant suitable up to 1600 dg C.