Thermochemical processes occurring in a titanium nitride coating under the effect of thermal laser pulses

The thermochemical processes in a TiN coating deposited on a steel substrate under cyclic irradiation with laser pulses are investigated. It has been established that the combustion of the coating in the irradiated regions occurs spatially inhomogeneously due to the uneven distribution of microregions in the coating, consisting of titanium nitride compounds with different stoichiometry. It is shown that dissociation reactions of various titanium nitride compounds with the release of free nitrogen occur inside the coating. As a result, the ratio of the mass fractions of titanium nitride compounds with different stoichiometry changes in comparison with the original coating. Diffusion of nitrogen into the steel substrate results in the formation of iron nitride.

Hydroxyapatite Formation on Coated Titanium Implants Submerged in Simulated Body Fluid

Titanium implants are commonly used in the field of dentistry for prosthetics such as crowns, bridges, and dentures. For successful therapy, an implant must bind to the surrounding bone in a process known as osseointegration. The objective for this ongoing study is to determine the potential of different implant surface coatings in providing the formation of hydroxyapatite (HA). The coatings include titanium nitride (TiN), silicon dioxide (SiO2), and quaternized titanium nitride (QTiN). The controls were a sodium hydroxide treated group, which functioned as a positive control, and an uncoated titanium group. Each coated disc was submerged in simulated body fluid (SBF), replenished every 48 h, over a period of 28 days. Each coating successfully developed a layer of HA, which was calculated through mass comparisons and observed using scanning electron microscopy (SEM) and energy dispersive analysis x-rays (EDX). Among these coatings, the quaternized titanium nitride coating seemed to have a better yield of HA. Further studies to expand the data concerning this experiment are underway.