Materials Science and Technology IX
Materials Research and Application II
Recent Development in Machining, Materials and Mechanical Technologies II
Advanced Materials and Engineering Materials VI
Mechanics of Masonry Structures Strengthened with Composite Materials II
Advanced Materials and Processes of Metalworking II
Orthopedic Biomaterials - From Materials Science to Clinical Applications
Symposium on Materials Science and Engineering
High Technology: Research and Applications 2016
21st Symposium on Composites
Analysis of Damage Features and Failures for Structural Materials and Parts
Advances on Manufacturing and Material Sciences
Advanced Materials and Processes of Metalworking II
摘要: The present study investigates the process of beverage can end forming from 5182 aluminum alloy. Stress-strain state during forming is analyzed using finite element method in PAM-Stamp 2G, and fracturing probability is evaluated based on V.L. Kolmogorov’s fracture criterion. It is established, that stress state does not provide the sufficient plasticity margin during ends forming. Blank material plasticity resource is depleted during preliminary and reverse drawing stages, defects accumulation during countersink forming is negligible. Minimum relative elongation value, responsible for fracture-free end forming, is 6% in the rolling direction.
摘要: Computer simulation of expansion of tubes by extrusion was performed. Deflected mode analysis was described. Influence of collar taper angle, radius of rounding in interface of conical and cylindrical sections of mandrel, geometry of blank on deformation behavior of tube during expansion was determined.
摘要: Intensive development of Russian aviation and aerospace industries put an emphasis to the problem of quality of using materials and workpieces and to the value of technical and economical indexes in the context of planned production level [1, 2]. Waste-free technologies are preferred. Cutting by torsion or cutting by shear are preferable technologies if thin-walled tube cutting is the main blanking operation. Build-up of workpiece deformation zone plays an important role in the cutting process. Deformation zone determines stability of details during further processing and exploitation. An extended research was conducted about tube separation process using torsion with an active counterpressure. Some parameters was defined in the result of research, in particular: distribution of deformation zone along length and thickness of workpiece, angular deflection and compression force and workpiece heating temperature impact on build-up of whisker disposition in the cut zone. It allows identifying optimum compression force range and temperature conditions. Compliance with recommended practices allows conducting thin-walled tube separation simultaneously with build-up on the workpieces whisker structure that is fortunate for further pressure treatment and exploitation.
摘要: In this paper weldability study of low-alloyed thermal resistant conductor alloys of Al-Cu-Mn and Al-Mg-Si alloying systems with different content of B, Sc, Fe, Zr and ability to resist corrosion in the welding area is presented. The effect of large intensive deformation in the welding area on the phase composition and the size of phases was determined.
摘要: Basic information and research results of the process combined rolling-extruding have been represented, which have been used to create new energy-saving technologies for obtaining of long deformed semi-finished products of small cross-section. It has been shown that such combined processing technologies may be applicable for the machining of low ductility and low-tech aluminium alloys with high metal yield and high productivity.
摘要: Stringer radiator panels made of aluminum and titanium alloys used in the hull structure of the aircraft, which is necessary to maintain the required temperatures. section of the channel profile has a predetermined geometry - a circular or rectangular cross-section of the channel, and the channel itself can be unilateral or bilateral. The technological process of production of radiator panels is to carry out one process machining position, consisting of a series of operations performed by the gas pressure diffusion bonding two sheets and hot-forming gas channels supplied between the sheets. We consider forming a shell of material, following the energy theory of creep and defectiveness. The expressions for the evaluation process and force parameters of damage, in particular - the destruction. The effect sizes of workpiece thickness in the dome, the relative magnitudes of changes in the geometric parameters and the magnitude of damage accumulated from the time of deformation under different laws for the loading of aluminum and titanium alloys. Comparison of theoretical and experimental data on the relative thickness of the dome blanks and reference points, as well as the relative height of the workpiece indicates satisfactory their agreement.
摘要: Objective of the work: develop a model for calculation of plate exit thickness. This model is supposed to improve process reliability in obtaining specified thickness with +/- 0.5 mm tolerance. The work identifies major influences on obtaining specified thickness and relationship of their effects. Based on derived relationships, the work develops rolling force calculation model with the following inputs: alloy grade, feedstock temperature, feedstock entry and exit gage, feedstock width, rotational speed of the rolls. Mill stand characteristics, like mill stiffness, backlash, work roll behavior, were studied in relation to force and temperature. The resulting model allows to predict the value of work roll gap increase during rolling. The model was validated in production environment and demonstrated high confidence level of calculation results.
摘要: The article represents theoretical analysis of friction influence on the process of formation experimental blank with several radial wedge-type branches having different constituent convergence angles. The authors show that with the correlation between volumes of material what are extruded into the branches it is possible to define the friction coefficient for set conditions of forging. Such approach allows suggesting the methodology for exact definition of friction coefficient for forged blank with a large area of contact surface. For the analysis the analytical model is used which was obtained by upper-bound approach technique. Calibration measurement of accuracy of a model was carried out by numerical method in Deform 3D.
摘要: It is proposed to use actual computer software systems, providing a visualization and automation of the wrinkling and visualization and automation of the results of the numerical finite-element modeling of stretch forming a convex-concave shape in view of the fact that the saddle-backed surface of the shell has two families of asymptotic real straight lines. Along these lines, the saddle-backed surface of the shell with convex-concave shape is easy to break up or riffles are formed along them. The objectives of computer simulation are to predict unwanted distortion geometric form of the shell because of wrinkling and to find a ways to minimize the deviations of its surface deviations from the required shape.