Obrabotka Metallov 2020 Vol. 22 No. 1

OBRABOTKAMETALLOV Vol. 22 No. 1 2020 52 TECHNOLOGY Expanded Titanium Meshes Based on Deformational Cutting Nikolai Zubkov * Bauman Moscow State Technical University, 5 Baumanskaya 2-ya, Moscow, 105005, Russian Federation https://orcid.org/0000-0003-3757-1299, zoubkovn@bmstu.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2020 vol. 22 no. 1 pp. 41–53 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2020-22.1-41-53 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 27 December 2019 Revised: 20 January 2019 Accepted: 14 February 2020 Available online: 15 March 2020 Keywords : Expanded metal Mesh Deformational cutting Hernioplasty Filtration Te fl on Titanium Funding This work was supported by the Ministry of Education and Science of Russia (Grant № 9.5617.2017/VU). Acknowledgements The author expresses gratitude to Ser- guey Korovushkin for the help in carry- ing out experiments. ABSTRACT Introduction . One of the fi elds of use of deformational cutting (DC) is the manufacturing of meshes from thin sheet materials. The principle of its production consists in fi nning of both side of the thin sheet in mutually perpen- dicular directions with a depth of cut more than half the thickness of the sheet. A signi fi cant disadvantage of such meshes is the small effective screening area (the ratio of the total area of holes to the mesh area). One of the prom- ising fi elds of use of meshes obtained by DC is hernioplasty as titanium implants for the treatment of hernias and reinforcement of bone and soft tissues. Implants require an effective screening area of more than 60 %, high compli- ance with plastic deformations, and a large speci fi c surface area to hold the tissues sprouting into the implant. In the paper, the DC method is considered as an alternative to the existing titanium woven mesh implants, which have an extremely high cost. Work objective is to study the main relationships of obtaining preforms for meshes by the DC method, the features of mesh stretching, and to analyse the resulting shapes and sizes of mesh cells. In this paper the two-sided fi nning of thin-sheet blanks of pure titanium VT1-00 with a mismatched direction of fi nning of opposite sides of the sheet in the range of fi ns crossing angles of 1.3°...10° with varying the angle of workpiece undercutting and the fi n pitch were studied . The analysis of the stretching mechanics for obtaining rhombic, hexagonal, and parallelogram forms of cells was carried out. Results and discussion. The range of fi n pitch and crossing angles that ensure the stability of the DC and stretching stability is set. The shape of the cell depends on the length of the fi ns bonding obtained on opposite sides of the sheet. Increasing the bond length with by a decreasing the crossing angle leads to the transition of the cell shape from rhombic to hexagonal. A cell in the form of a parallelogram is typical for the fi ns of the opposite sides, which have differences in bending strength. Conclusions: the method of deformational cutting is an alternative of metal punching for through-cutting sheet metal and polymer for its subsequent stretching in order to obtain meshes. The meshes obtained on the basis of DC have a large surface area and an increased ability to plastic deformation. It is justi fi ed to obtain the rhombic, hexagonal, and parallelogram forms of mesh cells. The shape of the mesh cell is controlled by selecting the fi ns crossing angle and the pitch of the fi ns on opposite sides of the workpiece. The largest cell size and maximum effective screening area of the mesh are provided by meshes with hexagonal cells form at the fi ns crossing angles on opposite sides of the workpiece less than 3°. For citation: Zubkov N.N. Expanded Titanium Meshes Based on Deformational Cutting. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2020, vol. 22, no. 1, pp. 41–53. DOI: 10.17212/1994-6309-2020-22.1-41-53. (In Russian). ______ * Corresponding author Zubkov Nikolai N. , D.Sc. (Engineering), Professor Bauman Moscow State Technical University 5 Baumanskaya 2-ya, Moscow, 105005, Russian Federation Tel.: +7-916-607-7948 , e-mail: zoubkovn@bmstu.ru References 1. Zubkov N.N., Ovchinnikov A.I. Method of producing a surface with alternating ridges and depressions and a tool for carrying out the said method . Patent EP 0727269 B1, 2000. 2. El’chinov V.P., Mitin E.V. Novye nerzhaveyushchie kozhukhotrubnye kondensatory vodyanogo okhlazhdeni- ya: sochetanie effektivnosti i nadezhnosti [New stainless shell-and-tube water-cooled condensers: a combination of ef fi ciency and reliability]. 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