Scratch testing of ceramic plasma-sprayed coatings

摘要

Plasma sprayed (PS) ceramic coatings have found widespread commercial use, particularly for wear resistant surfaces. While the comparative wear resistance of many coatings has been studied extensively, little research has been focused on the mechanism of material removal at the microscopic level. Understanding of the micromechanical basis of macroscopic weight loss through wear is very important for the development of improved coatings and better uses for existing coatings. The purpose of this study is to elucidate the wear mechanisms that occur when a plasma-sprayed ceramic coating is in sliding contact with a harder asperity, using controlled scratch testing as a model abrasion test. The present work attempts to relate the scratch test results to the microstructural integrity, or cohesion, of the various coatings.