Russian scientists developed a method of forming nano-sized grains in the structure of pure titanium allows us to improve some of its mechanical properties. Information about the studies of the structure and properties of nano-sized titanium, as well as implants made based on it, will be published in the May issue of the journal "Russian Nanotechnology." The work was supported by the Federal Target Program "Research and scientific-pedagogical personnel of innovative Russia for 2009-2013" and the analytical departmental target program "Development of Scientific Potential of Higher Education".
Set miniplates and minivintov of titanium tools mikroosteosinteza (for maxillo-facial surgery)
Titan — one of the most promising materials for surgical implants — prostheses implanted in the body, is widely used in traumatology. This unique material is biocompatible with the tissues of the body and even fused with the bone. Although titanium is strong enough material, though scientists in some cases, require higher durability qualities. To increase the strength researchers often administered in pure titanium impurities such as aluminum and vanadium. However, these alloying elements are harmful to the organism. Therefore, from the point of view of better biocompatibility need to find new ways of strengthening bio-inert pure titanium.
This compromise hardening is the formation of a pure titanium nanoscale grains by plastic deformation. Researchers at the Research and Education and Innovation Centre "Nanostructured Materials and Nanotechnology" and Belgorod State University, in collaboration with scientists from the All-Russian Scientific Research Design Institute of Medical Instruments Kazan studies have been conducted of the structure and mechanical properties of the nanostructured titanium.
To create the structure of nano-sized titanium grains scientists used an original method for plastic deformation, combining helical and longitudinal rolling. After carrying out a rolling metal forming titanium shafts subjected to annealing for stress relief. As a result of operations in the structure appears different grain sizes, including at least 100 nm, average size of a grain formed was 290 nm.
Then experts compared durability qualities treated unalloyed titanium and titanium alloyed with aluminum and vanadium. Mechanical tests showed an increase in the strength of titanium is almost twice as compared to its initial state. Moreover, the obtained values were approaching the values of the strength of doped titanium.
From the point of view of practical application of the interesting tests of finished products, namely titanium screws for trauma. In addition to high strength properties, the screws should have a significant plastic deformation in torsion. If the screw is not enough material is plastic, then in a real medical operation in prosthetics can be destroyed screws for installation design. As a result — the surgeon will have to drill out the remainder (the threaded part) of the bone screw and change the configuration of the installed structure. This procedure not only leads to an unplanned increase in operation time, but also increase the risk of malfunction implants. Tests titanium screws shown that nanostructured titanium has extremely high plasticity, the maximum torsion angle of the sample prior to its destruction is 410 degrees. This result is approximately 60 percent greater than the value of plasticity-doped titanium.
Hardening of titanium due to the formation of nanosized grains in pure titanium by value parameters of the mechanical properties equivalent to hardening due to alloying elements. According to scientists, this method of hardening — a worthy replacement of doping metals.
Source of information:
M. Ivanov, Yu R. Kolobov, EV vote, I. Kuzmenko VP Wayne, DA Nechaenko, ES Kungurtsev "Mechanical properties of nanostructured titanium mass production." Nanotechnologies in Russia, Volume 6, № 5-6.