ПОВЫШЕНИЕ ЭФФЕКТИВНОСТИ ЛАЗЕРНОЙ СВАРКИ ЭЛЕМЕНТОВ ИНТРАМЕДУЛЛЯРНОГО РАСШИРЯЕМОГО СТЕРЖНЯ ЗА СЧЕТ ОПТИМИЗАЦИИ ГЕОМЕТРИИ РЕБЕР

Abstract

The paper considers the problem of assembling the components of the innovative design of intramedullary extensible rod for lockable osteosynthesis, which was developed in Togliatti State University. Nowadays, the medical practice with application of intramedullary extensible rods is one of the most advanced methods of treatment of long bones fractures. The reducing of operating time, patient’s blood loss, and the X-ray dose of radiation of a patient and the staff provides opportunities for wide use of such structures in medical practice. That is why their development is a critical task. While finally assembling the device, one should take into account the rod structure technological characteristics as well as complex specificity of loads during the operational use. While carrying out experimental research, the authors used LKD4-015.150 laser machine for welding the rod components. The welding of the rod was performed in argon at a gas rate of 6 - 10 l/h with the heating zone additional protection. When welding the rod components with different thickness, the conditions of formation and the welding seam quality against the initial (without technological recess) and the proposed (with a technological rectangular recess of the rod rib) options were considered as the factors of variation. The authors measured the microhardness of welding seam and welded elements against the initial and proposed options. When welding according to the initial version, the rod tube melting through occurs. While analyzing microhardness in welding according to the initial version, the significant increase in the welding seam microhardness against the welded components is established. This factor promotes the destruction of welding seam at the rod loading. When analyzing microhardness in welding according to the proposed variant, the author has determined that the value of welding seam microhardness is comparable to microhardness of welded components. In this case, the rod tube melts for 0.1 mm, what allows maintaining its plasticity and ensures the rod efficiency during its loading.