The present paper describes the role of process conditions in developing phase-pure α-Al<inf>2</inf>O<inf>3</inf> coatings using solution precursor plasma spraying. Different precursor combinations were employed and two key parameters, namely plasma power and substrate pre-heat temperature, were varied. Detailed studies of in-flight formed particles and splat characteristics were found to correlate well with the Al<inf>2</inf>O<inf>3</inf> coating characteristics. The Al<inf>2</inf>O<inf>3</inf>-forming precursor formulation was also found to be crucial in determining the phase constitution of the deposited coatings. © 2015 ASM International