Method and apparatus for measuring the density and hardness of porous plasma sprayed coatings

摘要

This invention relates to a method for making porous metal plasma sprayed abradable seals. Radiation transmission techniques are utilized to determine the as-sprayed density of a deposit containing metal and polymer powder particles. Based on the measured density, a mathematical prediction is made of what the surface hardness of the sprayed deposit will be after it has been machined and then heated to remove the polymer powder particles. If the predicted hardness is outside of the desired range, changes are made in the plasma spray parameters.