Study of the hardness distribution after induction heat treatment of titanium over the surface and the cross-section

In this work, the mechanical properties (microhardness) of a titanium disk after induction heat treatment (IHT) were studied. The influence of the processing parameters (inductor current and temperature) on the distribution of microhardness over the cross-section of the experimental samples was established.

Antibacterial Activity against Staphylococcus Aureus of Titanium Surfaces Coated with Graphene Nanoplatelets to Prevent Peri-Implant Diseases. An In-Vitro Pilot Study

Dental implants are one of the most commonly used ways to replace missing teeth. Nevertheless, the close contact with hard and soft oral tissues expose these devices to infectious peri-implant diseases. To prevent such infection, several surface treatments have been developed in the last few years to improve the antimicrobial properties of titanium dental implants. In this in-vitro pilot study, the antimicrobial activity of titanium surfaces coated with different types of graphene nanoplatelets are investigated. Six different colloidal suspensions of graphene nanoplatelets (GNPs) were produced from graphite intercalated compounds, setting the temperature and duration of the thermal shock and varying the number of the exfoliation cycles. Titanium disks with sand-blasted and acid-etched surfaces were sprayed with 2 mL of colloidal GNPs suspensions. The size of the GNPs and the percentage of titanium disk surfaces coated by GNPs were evaluated through a field emission-scanning electron microscope. The antibacterial activity of the specimens against Staphylococcus aureus was estimated using a crystal violet assay. The dimension of GNPs decreased progressively after each sonication cycle. The two best mean percentages of titanium disk surfaces coated by GNPs were GNPs1050°/2 and GNPs1150°/2. The reduction of biofilm development was 14.4% in GNPs1150°/2, 20.1% in GNPs1150°/3, 30.3% in GNPs1050°/3, and 39.2% in GNPs1050°/2. The results of the study suggested that the surface treatment of titanium disks with GNPs represents a promising solution to improve the antibacterial activity of titanium implants.

Тритиевые источники электропитания на основе гетероструктур AlGaAs/GaAs

We report on the development of a radioisotope power source based on the AlхGaAs1-х/GaAs semiconductor converter of β-radiation and tritium as a radiation source. The transducer efficiencies are compared for three types of β-radiation sources: (i) the tritiated titanium disk, (ii) the tritium lamp of green luminescent glow, and (iii) gaseous tritium. When using a converter based on the Al0.35Ga0.65As/GaAs heterostructure in a tritium capsule, the efficiency η = 5.9% is found with the maximum output specific electric power of 0.56 µW/cm2. Due to the prolonged operational life, such autonomous and compact power sources can be utilized in space technology, underwater systems, growth implants, biomedical sensors, and portable mobile equipment of high realibility.