Key Engineering Materials Vol. 861

Abstract: The stretch stress of each layer of laminate composite undergoes complex changes after being stretched, which significantly affects the stretch strength. In order to determine the magnitude of the change, the paper directly solved the stretch stress using the analytical method through simple assumptions, and obtained the analytical calculation formula. Studies on double-layer plates show that the magnitude of stretch stress is closely related to the elastic modulus, length and thickness dimensions of the plate layer, the shear modulus of the adhesive, the thickness of the adhesive layer, and the external stress, and the maximum stress occurs at the middle section. The calculation of the formula provides a convenient way to check the stretch strength.

Abstract: In this paper, bionic designs and 3D modeling of external and internal porous scaffold with different pore sizes and porosities were precisely fabricated using CAD software. The mechanical performance and stress distribution pattern of two porous scaffolds were studied using finite element analysis. The results indicated that the static mechanical performance of external porous scaffold deteriorated with increasing pore size, and large peak stress and total deformation were observed. However, the calculated peak stress of internal porous scaffold was reduced by almost 58.3% to 69.4%, and the elastic modulus remains almost unchanged. The mechanical properties of porous scaffold can be optimized and greatly improved by adding a solid layer with a suitable thickness. The novel optimized design of porous scaffold is conducive to bone tissue repair and reconstruction.

Abstract: The results of computer simulation of the process of combined rolling-extruding of longish deformed semi-finished products from alloy 01417 are presented. A feature of the research is that continuously cast bars with a diameter of 12.5 mm obtained using an electromagnetic mold are used as a workpiece. This makes it possible to increase the manufacturability of processing and to obtain after rolling-extruding billets for drawing with a diameter of 5 mm with a large resource of plastic and strength properties. For this case the technological parameters and temperature and speed conditions of combined processing have not yet been studied, therefore, their analysis was performed using the Deform-3D software package. It has been revealed that the feasibility of the rolling-extruding process is significantly affected by the frequency of rotation of the rolls. Moreover, the process becomes unstable when the value of this parameter is 4 rpm, which can be explained by insufficient degrees of deformation during rolling, and consequently by the small value of the active friction forces acting on the contact surface of the metal with the rolls. As a result of this, the processing temperature conditions also change, which is also demonstrated using the developed computer model. As a result, it was found that for the stable course of the combined rolling-extruding process at the CRE-200 unit of a continuously cast billet with a diameter of 12.5 mm from alloy 01417 at a heating temperature of the billet of 550 °C and a tool of 200 °C, degree of deformation during rolling 44% and drawing ratio during extruding 18.6 the frequency of rotation of the rolls should be at least 8 rpm. The simulation data used during the implementation of the process at the combined processing unit CRE-200, the results of which made it possible to finally obtain electrotechnical wire with a diameter of 0.5 mm from 01417 alloy that meets the requirements of TS 1-809-63-2018.