Atmospheric plasma sprayed silica–hydroxyapatite coatings on magnesium alloy substrates

Silica-doped hydroxyapatite as a bioactive coating presents some advantages compared to the pure one, such as: increased in vivo bioactivity and early bone ingrowth. The aim of this study is to obtain a deposition of silica-doped hydroxyapatite on magnesium alloy plates by atmospheric plasma spraying. The coating material was prepared by a precipitation method with sodium silicate addition as a source of silica, and various methods were used to characterize it. Spraying conditions including powder feed rate and current values were varied. The coating properties were defined by determining the purity, phase composition, morphology and corrosion protection of the HAP–Si deposits on the magnesium plates.