Rare Earth doped Calcium Phosphate Ceramic Coating Fabricated by Laser Cladding and Its Degradation Behavior in Physiological Saline

Abstract:

Rare earth doped calcium phosphate ceramic composite coating was prepared on the surface of titanium alloy by using laser cladding technology. The interface, phases, micromorphology and iron release of the coating were respectively measured by a series of experimental methods including Optical microscope, X-Ray Diffraction, Scanning Electronica Microscope, Inductively Coupled Plasma Mass Spectrometry. The results are shown that calcium phosphate ceramic composite coating is obtained on the titanium surface by laser cladding, and the coating is rich in hydroxylapatite and tricalcium phosphate. The Ca-P coating consist of three parts which are substrate, alloyed layer and ceramic layer. And its interface is bonding excellent. As the weight lost, the coating can be degraded by physiological saline. And it is found that a new apatite-like phase is formed on the surface of the coating which soaked in physiological saline for three weeks. With the degradation of the coating, Ca₂₊ iron and La₃₊ iron release to physiological saline. The concentration of Ca₂₊ is wavelike rise with time in the range from 15 PPM ～ 40 PPM. But the concentration of La₃₊ is fluctuation decreased with time in the range from 0.15 PPB ～ 0.45 PPB.