Abstract: A composite thermal barrier coating system includes a first composite thermal barrier coating over a portion of a substrate, and a second deposited thermal barrier coating over edge portions of the substrate. The first composite coating is relatively thick and preferably includes friable graded insulation comprising an abradable honeycomb metallic structure filled with high thermal expansion ceramic hollow spheres in a phosphate bonded matrix. The second deposited edge coating is relatively thin and preferably comprises an electron beam physical vapor deposited thermal barrier coating comprising ZrO2 and Y2O3. The friable graded insulation may be manufactured to thicknesses in excess of current thermal barrier coating systems, thereby imparting greater thermal protection. Superior erosion resistance and abrasion properties are also achieved. The composite thermal barrier coating system is useful on combustion turbine components such as ring seal segments, vane segment shrouds, transitions and combustors.