M. B. Ivanov

Mechanical properties of mass-produced nanostructured titanium

The structure and mechanical properties of nanostructured titanium VT1-0 derived using an ingenious method which combines helical and longitudinal rolling are studied in comparison with the properties of commercial titanium alloys VT6 and VT16, as well as VT1-0 in a coarse-grained state. The mechanical properties of these materials are studied using quasi-static tensile and torsion tests (including finished products, i.e., implants for osteosynthesis), as well as fatigue tests. It is shown that the use of the developed method of severe plastic deformation is an efficient mode for the formation of a high-strength nanostructured state in titanium VT1-0, which exhibits sensitivity to stress concentrators under cyclic loading that is characteristic of titanium alloys and an extremely high reserve of torsional plasticity.

Elastoplastic properties of a low-modulus titanium-based β alloy

The elastoplastic properties (elastic modulus, amplitude-independent damping ratio, microplastic flow stress) of a Ti-26Nb-7Mo-12Zr titanium β alloy are determined using an acoustic resonance method. The effect of the strain during thermomechanical treatment on the structural features of the micro-crystalline alloy and, hence, its elastoplastic properties is analyzed.

Relationship between Osteoinductive Characteristics of Biocomposite Material and Physicochemical Characteristics of Coating

The osteoinductive characteristics of hydroxylapatite-based coating with different physicochemical characteristics were studied. The formation of the bone tissue on the studied types of the implant coating differed by the pattern and rate of formation of structural elements of the bone. Clear-cut phase-wise osteogenesis was seen on combined calcium phosphate coating: intense formation of the fibrous interstitial substance (due to cellular structure of hydroxylapatite) and slow maturing of cell elements. Bilayer composite coating provided (during the same period) the formation of more mature connective tissue. This phenomenon can be explained by better bioavailability of the coating material. The properties of combined calcium phosphate coating can be evaluated as mainly osteoconductive, while those of bilayer composite coating as osteoinductive.

Structure and properties of titanium β-alloys Ti-Nb-Mo-Zr of medical purpose

Low-modulus titanium β-alloy Ti-26Nb-7Mo-12Zr for medical application, composed of nontoxic elements V and Al was considered. The influence of deformation in combination with heat treatment on the structure and properties of β-alloys such as elastic modulus, yield strength and tensile strength, ductility was investigated.

Studies of structural-phase state of medical titanium alloys by contemporary methods of analytical electron microscopy

An example of original studies of titanium alloys for medical applications is used to discuss methodical features of analysis of the structural-phase state of metal materials with usage of contemporary methods of analytical scanning and transmission (including high-resolution) electron microscopy. Methods of X-ray energy dispersion spectroscopy and spectroscopy of characteristic electron energy loss are described and discussed. The possibilities of these methods for local (nanometer range) measurement of concentrations of alloying elements, including light ones (carbon), are shown. An example of focused ionic beam for study of grain boundary gliding in nanostructured pure titanium at room temperature is considered.