Making Dense Coatings with the Solution Precursor Plasma Spray Process

摘要

The Solution Precursor Plasma Spray process allows thecreation of coatings directly from chemical precursors, thusavoiding the task of making sprayable powders. To date, ourresearch has been based on injecting chemical precursors intoa DC plasma torch. The process has proven to be useful inmaking vertically cracked thermal barrier coatings and hasshown special advantages for making thick thermal barriercoatings (up to 4 mm). More recently, the process has beenmodified to produce dense, crack free coatings. Thisdevelopment was enabled by an improved understanding ofthe process, including making a coating almost exclusivelyfrom ultra-fine splats and avoiding the formation of verticalcracks. A crack free, dense alumina-yttria stabilized zirconiacoating has been produced which is 98% dense and has anaverage Vickers hardness (300 gf) of 1177.