Abstract
The Solution Precursor Plasma Spray process allows the creation of coatings directly from chemical precursors, thus avoiding the task of making sprayable powders. To date, our research has been based on injecting chemical precursors into a DC plasma torch. The process has proven to be useful in making vertically cracked thermal barrier coatings and has shown special advantages for making thick thermal barrier coatings (up to 4 mm). More recently, the process has been modified to produce dense, crack free coatings. This development was enabled by an improved understanding of the process, including making a coating almost exclusively from ultra-fine splats and avoiding the formation of vertical cracks. A crack free, dense alumina-yttria stabilized zirconia coating has been produced which is 98% dense and has an average Vickers hardness (300 gf) of 1177.
