Compositionally graded yttria-stabilized zirconia coating on stainless steel using laser engineered net shaping (LENS™)

Fully dense, compositionally graded yttria-stabilized zirconia coatings have been developed using LENS™. Due to high thermal gradients and cooling rates in LENS™, a fine coating microstructure with a hardness in the range of 1700–2000 Hv is produced. The rapid heat loss through the substrate resulted in the directional growth of grains along the thickness direction. The inherent advantage of this approach is its ability to simultaneously control composition and micron level features to produce feature-based thermal barrier coatings.