In this study, different composite coatings with 20 wt.% silicon and 1 wt.% multi-walled carbon nanotubes
of hydroxyapatite were developed on NiTi substrate using a combination of electrophoretic deposition and
reactive bonding during the sintering. Silicon was used as reactive bonding agent. During electrophoretic
deposition, the constant voltage of 30 V was applied for 60 s. After deposition, samples were dried and then
sintered at 850 C for 1 h in a vacuum furnace. SEM, XRD and EDX were used to characterize the
microstructure, phase and elemental identification of coatings, respectively. The SEM images of the coatings
reveal a uniform and compact structure for HA–Si and HA–Si–MWCNTs. The presence of silicon as a
reactive bonding agent as well as formation of new phases such as SiO2, CaSiO3 and Ca3SiO5 during the
sintering process results in compact coatings and consumes produced phases from HA decomposition.
Formation of the mentioned phases was confirmed using XRD analysis. The EDX elemental maps show a
homogeneous distribution of silicon all over the composite coatings. Also, the bonding strength of HA–Si–
MWCNTs coating is found to be 27.47 ± 1 MPa.