Magnesia-alumina spinel (MgAl₂O₄) is an oxide ceramic with broad applications as a high temperature and corrosion resistant ceramic. Its moderate coefficient of thermal expansion coefficient of 7-8×10^-6 K^-1 may allow it to be used as a plasma spray coating on metallic substrates such as stainless steel with a thermal expansion coefficient of 12×10^-6 K^-1.

Two important factors affecting the microstructure and properties of plasma sprayed coatings are the particle temperature and velocity in the plasma jet. The particle temperature and velocity are influenced by a substantial number of operating parameters. Using a statistical design of experiments approach, deposition parameters, microstructure, and physical properties of air plasma sprayed spinel coatings are linked through mapping versus in-flight particle temperature and velocity. The T-V maps provide a basis for depositing coatings with controlled structures.