Microstructure and Texture Evolution of 0.6 mm Ultra-Thin-Walled Tubes of Magnesium Alloys Fabricated by Multi-Pass Variable Wall Thickness Extrusion (VWTE)

2020 ◽  
Vol 993 ◽  
pp. 427-433
Author(s):  
Zhao Ming Yan ◽  
Zhen Dong Lian ◽  
Min Fang ◽  
Zhi Min Zhang ◽  
Jia Xuan Zhu ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Texture Evolution ◽  
Extrusion Direction ◽  
Area Reduction ◽  
Average Grain Size ◽  
Coarse Grains ◽  
Thin Walled Tube ◽  
Variable Wall Thickness ◽  
Thin Walled ◽  
Variable Wall

AZ80+0.4%Ce alloy ultra-thin-walled tube with a wall thickness of 0.6 mm was fabricated by multi-pass variable wall thickness extrusion (VWTE) at 693 K. Microsturcture and texture evolution were investigated. The results indicate that the average grain size decreases from ~47 μm of extruded alloy to ~8.9 μm after 5 passes VWTE. The total area reduction of Mg alloy tube is 91 %. Homogeneity of microstructure is improved obviously and the morphology of Mg17Al12 phases in coarse grains and fine DRXed grains exhibit lamellar and granular shapes, respectively. In addition to the microstructure evolution, the VWTEed tubes showed a strong texture of (0001) planes, and the intensity decreased with deformation increasing to 4 passes. After 5p-VWTE, a strong texture characterized by (0001) pole tilting 20 degrees rotated from extrusion direction (ED) towards normal direction (ND).

scholarly journals Research on AZ80 + 0.4%Ce (wt %) Ultra-Thin-Walled Tubes of Magnesium Alloys: The Forming Process, Microstructure Evolution and Mechanical Properties

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 563 ◽  
Author(s):  
Zhaoming Yan ◽  
Min Fang ◽  
Zhendong Lian ◽  
Zhimin Zhang ◽  
Jiaxuan Zhu ◽  
...  
Keyword(s):  
Magnesium Alloys ◽  
Wall Thickness ◽  
Vickers Hardness ◽  
Hardness Test ◽  
Optical Microscope ◽  
Forming Process ◽  
Average Grain Size ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Variable Wall

Ultra-thin-walled tubes of magnesium alloys have received more and more attention in producing precision components for medical devices. Therefore, thin-walled tubes with high quality are desperately needed. In this study, the process of multi-pass variable wall thickness extrusion was carried out on an AZ80 + 0.4%Ce Mg alloy with up to five passes—one-pass backward extrusion and four-pass extension—to fabricate the seamless thin-walled tube with an inside diameter of 6.0 mm and a wall thickness of 0.6 mm. The average grain size decreased from 46.3 μm to 8.9 μm at the appropriate deformation temperature of 350 °C with the punch speed of 0.1 mm/s. X-ray diffraction (XRD), optical microscope (OM), scanning electron microscopy (SEM), and the Vickers hardness (HV) tester were utilized to study the phases, microstructure, and hardness evolution. It can be observed that low deformation temperatures (240 °C and 270 °C) and low strain (1 pass extrusion and 1 pass extension) lead to twins that occupy the grains to coordinate deformation, and a slip system was activated with the accumulation of strain. The results of the Vickers hardness test showed that twinning, precipitation of second phases, twinning dynamic recrystallization (TDRX), and work hardening were combined to change the hardness of tubes at 240 °C and 270 °C. The hardness reached 93 HV after the third pass extension without annealing at 350 °C.

scholarly journals The Effect of Geometrical Non-Linearity on the Crashworthiness of Thin-Walled Conical Energy-Absorbers

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4857
Author(s):  
Michal Rogala ◽  
Jakub Gajewski ◽  
Miroslaw Ferdynus
Keyword(s):  
Energy Absorption ◽  
Wall Thickness ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Cross Sectional ◽  
Variable Wall Thickness ◽  
Thin Walled ◽  
Variable Wall ◽  
Energy Absorbers ◽  
Energy Absorbing

Crashworthiness of conical shells is known to depend on various factors. This study sets out to determine the extent to which the cross-sectional diameter contributes to their energy-absorbing properties. The object of the study was thin-walled aluminium tubes varying in upper diameter and wall thickness. The components were subjected to dynamic axial crushing kinetic energy equal to 1700 J. The numerical analysis was performed using Abaqus 6.14 software. The specific aim of the study was to determine the extent to which variable wall thickness affects the energy absorption capacity of the components under study. From the simulations, we have managed to establish a relationship between total energy absorption capacity and wall thickness. The results from the conducted analyses and the purpose-specific neural networks could provide the base for the future methodology for forecasting and optimisation of energy-absorbing systems.

scholarly journals Extrusion of magnesium alloy hollow profiles with axial variable wall thickness

2019 ◽  
Author(s):  
Maik Negendank ◽  
Vidal Sanabria ◽  
Sören Müller ◽  
W. Reimers
Keyword(s):  
Magnesium Alloy ◽  
Wall Thickness ◽  
Variable Wall Thickness ◽  
Variable Wall

Obtaining Body Parts with Variable Wall Thickness Along the Perimeter

2021 ◽  
pp. 473-479
Author(s):  
Yuliya Bessmertnaya ◽  
Alexander Malyshev ◽  
Vladimir Vikhorev ◽  
Pavel Romanov
Keyword(s):  
Wall Thickness ◽  
Body Parts ◽  
Variable Wall Thickness ◽  
Variable Wall

The Bending of Curved Pipes With Variable Wall Thickness

2003 ◽  
Vol 70 (2) ◽  
pp. 253-259 ◽  
Author(s):  
V. P. Cherniy
Keyword(s):  
Cross Section ◽  
Wall Thickness ◽  
Shell Theory ◽  
Neutral Line ◽  
Radius Of Curvature ◽  
Curved Pipes ◽  
Variable Wall Thickness ◽  
Previous Solution ◽  
Variable Wall ◽  
Thin Shell Theory

A general solution is presented for the in-plane bending of short-radius curved pipes (pipe bends) which have variable wall thickness. Using the elastic thin-shell theory, the actual radius of curvature of the pipe’s longitudinal fibers and displacement of the neutral line of the cross section under bending are taken into account. The pipe’s wall thickness is assumed to vary smoothly along the contour of the pipe’s cross section, and is a function of an angular coordinate. The solution uses the minimization of the total energy, and is compared to our previous solution for curved pipes with constant wall thickness.

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