scholarly journals Effect of Cross Section Reduction on the Mechanical Properties of Aluminium Tubes Drawn With Variable Wall Thickness

Author(s):  
Q. H. Bui ◽  
R. Bihamta ◽  
M. Guillot ◽  
A. Rahem ◽  
M. Fafard

Variable thickness tube drawing is a new process for the production of high performance tubes. In this study, experiments were conducted to evaluate the effect of cross section reduction on the microstructure and mechanical properties of variable thickness aluminium tubes drawn using two different position controlled mandrel techniques. Various tubes with three different outer diameters were subjected to cold drawing at room temperature from 11% to 41% cross section reduction. The local mechanical properties were determined from tensile tests carried out on specimens cut from different positions in the tubes parallel to their axes. The distributions of the Vickers hardness over the surfaces at 0 deg and 90 deg to the drawing direction were examined. It was found that the microhardness, yield strength, and ultimate tensile of the deformed samples increase and the corresponding elongation decreases with the increase of cross section reduction. Also, the anisotropy in microstructure and mechanical properties is more significant with increasing of cross section reduction. The evolution of mechanical properties of drawn tubes versus cross section reduction depends on the mandrel shapes and initial tube outer diameter. This study helps to further understand the microstructure and mechanical properties evolutions during tube drawing process with variable thickness.

2010 ◽  
Vol 667-669 ◽  
pp. 133-137 ◽  
Author(s):  
Tibor Kvačkaj ◽  
Michal Kvačkaj ◽  
Volodymir Stoyka ◽  
Robert Kočiško ◽  
Jana Bidulská ◽  
...  

The influence of severe plastic deformation (SPD) on distribution of effective stresses, effective strains and temperatures during equal channel angular rolling (ECAR) process is mathematically simulated. Effect of ECAR processing on substructural and mechanical properties of oxygen free high conductivity (OFHC) Cu material is investigated too. Mathematical simulations in software DEFORM-3D, ECAR technology, tensile tests, EBSD analysis were used as experimental methods. Mathematical simulations of first ECAR pass referred on following results: effective normal stress had low heterogeneity with value 385 MPa, effective strain was distinguished with high heterogeneity in cross section of sample (φ=1,5-3) and temperature in deformation zone achieved value 150 °C. Mechanical properties after cold drawing were: Rp0,2 = 217 MPa, Rm = 260 MPa, Z = 63 % and after sixth ECAR pass were: Rp0,2 = 412 MPa, Rm = 426 MPa, Z = 72 %. From experiments is resulting the stabilization of mechanical properties after fourth ECAR pass were obtained.


2021 ◽  
Vol 13 (10) ◽  
pp. 5494
Author(s):  
Lucie Kucíková ◽  
Michal Šejnoha ◽  
Tomáš Janda ◽  
Jan Sýkora ◽  
Pavel Padevět ◽  
...  

Heating wood to high temperature changes either temporarily or permanently its physical properties. This issue is addressed in the present contribution by examining the effect of high temperature on residual mechanical properties of spruce wood, grounding on the results of full-scale fire tests performed on GLT beams. Given these tests, a computational model was developed to provide through-thickness temperature profiles allowing for the estimation of a charring depth on the one hand and on the other hand assigning a particular temperature to each specimen used subsequently in small-scale tensile tests. The measured Young’s moduli and tensile strengths were accompanied by the results from three-point bending test carried out on two groups of beams exposed to fire of a variable duration and differing in the width of the cross-section, b=100 mm (Group 1) and b=160 mm (Group 2). As expected, increasing the fire duration and reducing the initial beam cross-section reduces the residual bending strength. A negative impact of high temperature on residual strength has also been observed from simple tensile tests, although limited to a very narrow layer adjacent to the charring front not even exceeding a typically adopted value of the zero-strength layer d0=7 mm. On the contrary, the impact on stiffness is relatively mild supporting the thermal recovery property of wood.


2013 ◽  
Vol 811 ◽  
pp. 9-13 ◽  
Author(s):  
Zakaria Boumerzoug ◽  
Zakaria Boumerzoug ◽  
Vincent Ji

In this present investigation, the mechanical properties of industrial drawn copper wires have been studied by creep tests, tensile tests and hardness Vickers. The effect of prior heat treatments at 500°C for different time on the drawn wires behavior was the main goal of this investigation. We have found that these heat treatments influenced the creep behavior of drawn wires and recorded shape curves. The creep tests were applied under ambient atmosphere at 240 °C. The creep duration before rupture decreased with the prior heat treatment time. The creep tests results were confirmed by tensile tests. A relationship between the hardness and the ultimate tensile strength of this industrial material has been established. Optical and scanning electron microscopy observations have been also used. Cross section observations of the wire after tensile or creep-rupture tests have shown that the mechanism of rupture was mainly controlled by the void formation.


Author(s):  
Reza Bihamta ◽  
Guillaume D’Amours ◽  
Quang-Hien Bui ◽  
Ahmed Rahem ◽  
Michel Guillot ◽  
...  

The variable thickness tube drawing is a new modification in the tube drawing methods which enables production of axially variable thickness tubes faster and easier in comparison with other similar methods like radial forging or indentation forging. The production of this type of tubes can be used in optimum design of mechanical parts which do not necessarily need constant thickness along the axis of tube and this method can strikingly reduce the overall weight of parts and mechanical assemblies like cars. In this paper, the variable thickness tube drawing were parameterized in a MATLAB code and optimized with the Ls-Opt software as an optimization engine and Ls-Dyna as a FE solver. The final objective of this optimization study is to determine the minimum thickness which can be produced in one step by this method with various tube dimensions (tube thickness and outer diameter). For verification of results, some experiments were performed in the tube drawing machine which was fabricated by this research group and acceptable correspondence was observed between numerical and experimental results.


2019 ◽  
Vol 38 (2019) ◽  
pp. 892-896 ◽  
Author(s):  
Süleyman Tekeli ◽  
Ijlal Simsek ◽  
Dogan Simsek ◽  
Dursun Ozyurek

AbstractIn this study, the effect of solid solution temperature on microstructure and mechanical properties of the AA7075 alloy after T6 heat treatment was investigated. Following solid solution at five different temperatures for 2 hours, the AA7075 alloy was quenched and then artificially aged at 120∘C for 24 hours. Hardness measurements, microstructure examinations (SEM+EDS, XRD) and tensile tests were carried out for the alloys. The results showed that the increased solid solution temperature led to formation of precipitates in the microstructures and thus caused higher hardness and tensile strength.


2018 ◽  
Vol 284 ◽  
pp. 615-620 ◽  
Author(s):  
R.M. Baitimerov ◽  
P.A. Lykov ◽  
L.V. Radionova

TiAl6V4 titanium base alloy is widely used in aerospace and medical industries. Specimens for tensile tests from TiAl6V4 with porosity less than 0.5% was fabricated by selective laser melting (SLM). Specimens were treated using two heat treatment procedures, third batch of specimens was tested in as-fabricated statement after machining. Tensile tests were carried out at room temperature. Microstructure and mechanical properties of SLM fabricated TiAl6V4 after different heat treatments were investigated.


2010 ◽  
Vol 638-642 ◽  
pp. 3479-3484 ◽  
Author(s):  
Roberta O. Rocha ◽  
Tulio M.F. Melo ◽  
Dagoberto Brandao Santos

The influence of continuous annealing variables on the microstructure and mechanical properties of a C-Mn Dual Phase (DP) steel was studied. The annealing cycles were simulated using a Gleeble machine. Some specimens were quenched at different stages of the annealing cycle in order to evaluate the microstructural evolution during the annealing process. Tensile tests and microstrutural analysis were carried out. The results showed that high heating rates increased the final recrystallization temperature and as a consequence the microstructure obtained was refined. Austenite grain nucleation and growth were also influenced by the heating rates. Soaking temperature was the most influent variable on the mechanical properties, i. e., the yield strength increased and the tensile strength decreased with an increase in the soaking temperature. Microstructural analysis showed that not only martensite, but also bainite and martensite-retained autenite constituent (MA) were formed. Undissolved carbides were also detected by transmission electron microscopy.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 603
Author(s):  
Natalia Rońda ◽  
Krzysztof Grzelak ◽  
Marek Polański ◽  
Julita Dworecka-Wójcik

This work investigates the effect of layer thickness on the microstructure and mechanical properties of M300 maraging steel produced by Laser Engineered Net Shaping (LENS®) technique. The microstructure was characterized using light microscopy (LM) and scanning electron microscopy (SEM). The mechanical properties were characterized by tensile tests and microhardness measurements. The porosity and mechanical properties were found to be highly dependent on the layer thickness. Increasing the layer thickness increased the porosity of the manufactured parts while degrading their mechanical properties. Moreover, etched samples revealed a fine cellular dendritic microstructure; decreasing the layer thickness caused the microstructure to become fine-grained. Tests showed that for samples manufactured with the chosen laser power, a layer thickness of more than 0.75 mm is too high to maintain the structural integrity of the deposited material.


2019 ◽  
Vol 46 (8) ◽  
pp. 0802003
Author(s):  
周显新 Xianxin Zhou ◽  
辛博 Bo Xin ◽  
巩亚东 Yadong Gong ◽  
张伟健 Weijian Zhang ◽  
张海权 Haiquan Zhang

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3102
Author(s):  
Tianshuo Zhao ◽  
Yaobo Hu ◽  
Fusheng Pan ◽  
Bing He ◽  
Maosheng Guan ◽  
...  

High performance Mg–6Al–3Sn–0.25Mn–xZn alloys (x = 0, 0.5, 1.0, 1.5, and 2.0 wt %) without rare earth were designed. The effects of different Zn contents on the microstructure and mechanical properties were systematically investigated. The addition of Zn obviously refines the as-cast alloys dendritic structure because of the increase in the number in the second phase. For the as-extruded alloys, an appropriate amount of Zn promotes complete recrystallization, thus increasing the grain size. As the Zn content increases, the texture gradually evolves into a typical strong basal texture, which means that the basal slip is difficult to initiate. Meanwhile, the addition of Zn promotes the precipitation of small-sized second phases, which can hinder the dislocation movement. The combination of texture strengthening and precipitation strengthening is the main reason for the improvement of alloys’ strength.


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