Effect of ultrasonic operative power on bioactive calcium phosphate coatings on carbon/carbon composites

Bioactive calcium phosphate (brushite, CaHPO_4·2H_2O) coatings on carbon/carbon composites were prepared by a cathode sonoelectrodepostion process. The effect of ultrasonic operative power, current density and voltage on morphology, structure and adhesion to the carbon/carbon composites were investigated by SEM, EDAX, FTIR and XRD. Results show that the current density and voltage can be kept constant during sonoelectrodepostion, indicating that this process has a self-optimizing character. The morphologies of the brushite coating is flake-like, consisting of two of monoclinic phases. The residue pores in the original C/C composite are retained. The bioactive brushite coatings cannot be exfoliated by ultrasound below a critical operating power.