Electrodeposition of dicalcium phosphate dihydrate coatings on stainless steel substrates

Abstract

Cathodic reduction of an aqueous solution containing dissolved calcium and phosphate ions results in the deposition of micrometer thick CaHPO 4·2H2O (dicalcium phosphate dihydrate) coatings on stainless steel substrates. The coating obtained at a low deposition current (8 mA cm-2) comprises lath-like crystallites oriented along 020. The 020 crystal planes are non-polar and have a low surface energy. At a high deposition current (12 mA cm-2), platelets oriented along 121̄ are deposited. CaHPO4·2H2O is an important precursor to the nucleation of hydroxyapatite, the inorganic component of bones. Differently oriented CaHPO4·2H2O coatings transform to hydroxyapatite with different kinetics, the transformation being more facile when the coating is oriented along 121̄. These observations have implications for the development of electrodeposited biocompatible coatings for metal endoprostheses for medical applications. © Indian Academy of Sciences.