Morphological evolution and bonding strength of a monetite coating on the Ti-6Al-4V substrate via hydrothermal treatment

Monetite (CaHPO4) was coated on the Ti-6Al-4 V substrate by hydrothermal method. SEM, XRD, EDS, XPS, Raman spectroscope, and tensile test were used to characterize the morphology, phase constitutes, elemental content, elemental valence states, chemical functional groups, and bonding strength of the coating, respectively. It was revealed that the elevated temperature and prolonged duration time are favourable to the purity, densification and crystallinity of the monetite coating. The maximum bonding strength of 17.03 ± 2.79 MPa is found at the hydrothermal treatment temperature of 190 ℃ and duration time of 8 h. Both simulated mineralization experiment and the degradation experiment show that the monetite coating have good bioactivity and chemical stability, and is promising to be applied in the field of orthopaedic implant materials.