Bioactive HA coating was formed on the surface of Gr.5 medical titanium using the coating preparation technique, On the one hand, it can effectively improve the surface activity of Ti6Al4V implants, On the other hand, it can also increase its biocompatibility.
Clinical practice shows that HA coating has a certain promoting effect on bone tissue growth, However, the HA coating did not show strong bonding with the Ti6Al4V substrate, Resulting in easy premature peeling of the coating, causing inflammatory reactions in the body, affecting implant longevity.
Stanishevsky et al mixed different ratios of calcium nitrate, and titanium isopropoxide, and prepared the sol gol method on Gr.5 medical titanium surface with a thickness of 3 μ M of CaTiO3 coating, The mechanical bonding strength of the tested coatings to the Ti6Al4V substrate could be increased to 70 MPa, Improved properties of Ti6Al4V alloy, However, the process has a long cycle time and high cost of raw materials.
Oliveira et al used CaCl2 solution as an electrolyte to prepare CaTiO3 coating on Ti6Al4V surface by electric spark processing technique, through process parameter adjustment, The coating thickness can reach 200 μ m. The indicators such as thickness and hardness meet the medical requirements of the materials, But bubble holes and cracks are easily generated during the preparation of the coating, and the consistency of the coating surface is difficult to guarantee, which affects the preparation quality of the coating.
