Investigation Of The Properties Of Biocomposite Plasma Coatings "Titanium-Magnesium-Substituted Calcium Phosphates"

Complex investigations of the physicochemical properties of coatings obtained by plasma spraying of magnesium-substituted hydroxyapatite and tricalcium phosphate powders on a titanium base are carried out, and their comparative characteristics are given. Infrared spectroscopy and X-ray phase analysis of substituted powders confirmed their structure. According to transmission electron microscopy, the powder particles of magnesium-substituted hydroxyapatite have an elongated rectangular shape, flat edges, the size of individual particles from 500 nm to 2-3 μm. The magnesium-substituted tricalcium phosphate powder is represented by particles ranging in size from 300 nm to 7 μm, nanometer-scale particles are cylinders, whereas the shape of larger particles is close to rectangular. Scanning electron microscopy of plasma-dust coatings shows that a coating based on magnesium-substituted tricalcium phosphate, unlike magnesium-substituted hydroxyapatite, is formed by smaller particles with clear boundaries, resulting in a more uniform microrelief, but in turn a coating based on magnesium-substituted hydroxyapatite contains more micro- and nano-formations . The maximum force at which the samples with the plasma-dust coating on the basis of magnesium-substituted hydroxyapatite were taken off was 5.4 kN, and the magnesium-substituted tricalcium phosphate was 5 kN. The calculated adhesion values for coatings are 14.9 and 13 MPa, respectively. The coatings under investigation are characterized by pronounced hydrophilic properties. The surface energy for both types of coating is determined primarily by the polar component, and not by the dispersion component, which indicates the presence of polar groups on the surface.