Effect of process parameters on the crystallization and morphology of calcium phosphate at a constant pressure of 80 Torr

The effect of process parameters on the crystallization and morphology of calcium phosphate bioceramics produced using electrochemical deposition on a Ti–6Al–4V substrate under 80 Torr have been investigated. The calcium phosphate was deposited in a 0.04 M Ca(H2PO4)2·H2O (MCPM) solution on a Ti–6Al–4V substrate at 0–60 °C and 4–10 V for 1 h. X-ray diffraction, scanning electron microscopy and energy dispersive spectrometry were used to characterize the deposited samples. The dominant reaction under 80 Torr occurred within the first 1200 s. The X-ray diffraction results demonstrated that the deposit is mostly composed of dicalciumphosphate dehydrate, with hydroxyapatite as the minor phase, when deposited at 0 °C and 4–10 V for 1 h. Moreover, the content of the hydroxyapatite phase increases along with the deposition temperature and applied voltage. In addition, the crystallinity of the hydroxyapatite phase improves as the deposition duration increases from 20 to 120 min. When electrodeposited at 5 V and 0 °C, the crystals are mostly in a platelet form and have some needle-like dicalciumphosphate dehydrate crystals. When deposited at 30 °C and 60 °C, both platelet and needle forms of the dicalciumphosphate dehydrate co-exist in the sample. The size of the dicalciumphosphate dehydrate platelets decrease as the electrolyte temperature increases.