Characteristics of Plasticity and Microstructure of Hot Forming Magnesium Alloys Mg-Al-Zn Type / Charakterystyki Plastycznosci I Mikrostruktura Odkształcanych Na Goraco Stopów Magnezu Typu Mg-Al-Zn

2013 ◽  
Vol 58 (1) ◽  
pp. 151-156 ◽  
Author(s):  
D. Kuc ◽  
E. Hadasik ◽  
I. Schindler ◽  
P. Kawulok ◽  
R. Sliwa
Keyword(s):  
Activation Energy ◽  
Plastic Deformation ◽  
Magnesium Alloys ◽  
Hot Forming ◽  
Aluminium Content ◽  
Test Results ◽  
Compression Tests ◽  
Hot Plastic Deformation ◽  
Twin Formation ◽  
Reduction Of Area

The paper presents analysis of plasticity characteristics and microstructure of magnesium alloys for hot plastic treatment with different aluminium content (3÷8%). Tests were conducted for assessment of susceptibility of tested alloys to hot plastic deformation. A tensile test was run in temperature from 250 to 450°C. Based on the results, ultimate tensile strength (UTS) and reduction of area (Z) were determined for samples. Conducted compression tests allowed to specify the flow stress and microstructure changes after deformation. The activation energy in hot forming was determined for investigated alloys. The parameters of the process where flow is significantly influenced by twin formation in microstructure were determined. A varied plasticity of tested alloys was found depending on aluminium content. Test results will be useful in development of forging technology of selected construction elements which serve as light substitutes for currently used materials.

Evaluation of Friction Properties of Magnesium Alloy during Hot Forging by Ring Compression Test

2017 ◽  
Vol 889 ◽  
pp. 119-126
Author(s):  
Sueji Hirawatari ◽  
Hisaki Watari ◽  
Shinichi Nishida ◽  
Yuki Sato ◽  
Mayumi Suzuki
Keyword(s):  
Magnesium Alloys ◽  
Compression Test ◽  
Hot Forging ◽  
Hot Forming ◽  
Compression Tests ◽  
Ring Compression Test ◽  
Stress Strain ◽  
Friction Coefficients ◽  
Ring Compression ◽  
Velocity Motion

This paper deals with friction properties and deformation resistance during hot forming of Mg-Al-Ca-Mn series magnesium alloys. Friction coefficients between dies and magnesium alloys were obtained by ring compression tests that used graphite, PTFE, and an oil lubricant in a hot-forging process. Hot forging was performed under various conditions to clarify the effects of types of lubricants and slide motion of the press machines on friction properties. Two types of slide motion, a constant velocity motion and a pulse motion were selected in the ring-compression test. It was found that graphite with an oil lubricant effectively eliminated die sticking in hot forming of magnesium alloys. The isothermal deformation resistances were derived using friction coefficients obtained by ring-compression tests as well as finite-element simulations. The predicted stress strain curves with temperature were examined with the stress-strain relationship obtained in experiments using a servo press and demonstrated the effectiveness of the proposed method.

Effect of hot forming on anisotropy of mechanical properties of high-temperature 901 alloy

2021 ◽  
pp. 459-463
Author(s):  
A.V. Pchel'nikov ◽  
V.A. Filyakova ◽  
A.A. Sidorov
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
High Temperature ◽  
Hot Forming ◽  
Test Results ◽  
Initial Blank ◽  
Anisotropy Of Mechanical Properties

The effect of the macrostructure drawing after forming of blank made of high-temperature 901 alloy on the anisotropy of mechanical properties is studied. The effect of drawing on anisotropy is considered taking into account the unevenness of plastic deformation during upsetting and taking into account the deformation accumulated during the forging of the rod for the initial blank. The results of upsetting simulation and the test results of the samples mechanical properties cut in different directions of the blank fiber are presented.

An Experimental Study on Lubrication Behavior of Glass Lubricants during Hot Plastic Deformation of Ni-Based Alloys

2012 ◽  
Vol 591-593 ◽  
pp. 960-964
Author(s):  
Rui Li ◽  
Chao Yang Sun ◽  
Qing Dong Zhang
Keyword(s):  
Plastic Deformation ◽  
Strain Rate ◽  
Friction Factor ◽  
Flow Behavior ◽  
Compression Tests ◽  
Hot Plastic Deformation ◽  
Ring Compression ◽  
Specimen Material ◽  
Inconel 690 ◽  
Lubrication Performance

Friction factor and flow behavior of melt glass lubricants A5 and up68/2886 during hot plastic deformation of Ni-based alloys Incoloy800H and Inconel 690 were studied by using ring compression tests. The results indicated that glass up68/2886 had higher mobility than glass A5. Friction factor between interfaces went up with temperature in sufficient lubrication, but the opposite in inadequate lubrication, and the friction factor went down with strain rate under both conditions. Besides, yield strength of specimen material also slightly influenced lubrication performance of glass lubricants in inadequate lubrication. Low friction factor about 0.1 was still obtained in inadequate lubrication by using glass up68/2866, therefore excellent performance could be expected when glass up68/2886 was used properly such as at higher strain rate.

Microstructure and Plastic Deformation Behavior of Modified AA7075-T6 Aluminum Alloy

2014 ◽  
Vol 893 ◽  
pp. 424-429 ◽  
Author(s):  
Kyu Sik Kim ◽  
Gwan Yeung Kim ◽  
Si Young Sung ◽  
Bum Suck Han ◽  
Yong Nam Kwon ◽  
...  
Keyword(s):  
Activation Energy ◽  
Plastic Deformation ◽  
Deformation Behavior ◽  
Processing Map ◽  
Strain Rates ◽  
Compression Tests ◽  
Deformation Region ◽  
Plastic Deformation Behavior ◽  
Second Phases ◽  
Similar Area

This study investigated the plastic deformation behavior and microstructure evolution of the modified AA7075 alloy (using Eco-Mg in lieu of Mg element). Before the compression tests, the microstructure was observed and phase analysis was performed. As the conditions for the compression tests, temperature range was from 523K to 723K and strain rates were controlled from 10-2 s-1 to 10 s-1 using Gleeble equipment. The flow stress of the modified AA7075 alloy with their small grain size and second phases were slightly higher than that of conventional AA7075 alloy. The activation energy for the plastic deformation of this alloy was about 135.9kJ/mol, a relatively lower value compared with the conventional AA7075 alloy (more than 140kJ/mol). The processing map of the modified AA7075-T6 alloy was plotted and compared with that of conventional alloys. This alloy showed similar formability with the conventional AA7075 alloy, i.e., similar area of stable deformation region. We also attempted to discuss plastic deformation behavior related to its microstructure.

scholarly journals Confinement effects for rubberised concrete in tubular steel cross-sections under combined loading

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
A. Mujdeci ◽  
D. V. Bompa ◽  
A. Y. Elghazouli
Keyword(s):  
Axial Compression ◽  
Cross Section ◽  
Cross Sections ◽  
Image Correlation ◽  
Combined Loading ◽  
Test Results ◽  
Compression Tests ◽  
Confinement Effects ◽  
Rubber Content ◽  
Dependent Modification

AbstractThis paper describes an experimental investigation into confinement effects provided by circular tubular sections to rubberised concrete materials under combined loading. The tests include specimens with 0%, 30% and 60% rubber replacement of mineral aggregates by volume. After describing the experimental arrangements and specimen details, the results of bending and eccentric compression tests are presented, together with complementary axial compression tests on stub-column samples. Tests on hollow steel specimens are also included for comparison purposes. Particular focus is given to assessing the confinement effects in the infill concrete as well as their influence on the axial–bending cross-section strength interaction. The results show that whilst the capacity is reduced with the increase in the rubber replacement ratio, an enhanced confinement action is obtained for high rubber content concrete compared with conventional materials. Test measurements by means of digital image correlation techniques show that the confinement in axial compression and the neutral axis position under combined loading depend on the rubber content. Analytical procedures for determining the capacity of rubberised concrete infilled cross-sections are also considered based on the test results as well as those from a collated database and then compared with available recommendations. Rubber content-dependent modification factors are proposed to provide more realistic representations of the axial and flexural cross-section capacities. The test results and observations are used, in conjunction with a number of analytical assessments, to highlight the main parameters influencing the behaviour and to propose simplified expressions for determining the cross-section strength under combined compression and bending.

scholarly journals The Effect of α-Al(MnCr)Si Dispersoids on Activation Energy and Workability of Al-Mg-Si-Cu Alloys during Hot Deformation

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiaoguo Wang ◽  
Jian Qin ◽  
Hiromi Nagaumi ◽  
Ruirui Wu ◽  
Qiushu Li
Keyword(s):  
Activation Energy ◽  
Aluminum Alloys ◽  
Constitutive Equation ◽  
Hot Deformation ◽  
Flow Instability ◽  
Void Formation ◽  
Activation Energies ◽  
Compression Tests ◽  
Softening Mechanism ◽  
Dynamic Softening

The hot deformation behaviors of homogenized direct-chill (DC) casting 6061 aluminum alloys and Mn/Cr-containing aluminum alloys denoted as WQ1 were studied systematically by uniaxial compression tests at various deformation temperatures and strain rates. Hot deformation behavior of WQ1 alloy was remarkably changed compared to that of 6061 alloy with the presence of α-Al(MnCr)Si dispersoids. The hyperbolic-sine constitutive equation was employed to determine the materials constants and activation energies of both studied alloys. The evolution of the activation energies of two alloys was investigated on a revised Sellars’ constitutive equation. The processing maps and activation energy maps of both alloys were also constructed to reveal deformation stable domains and optimize deformation parameters, respectively. Under the influence of α dispersoids, WQ1 alloy presented a higher activation energy, around 40 kJ/mol greater than 6061 alloy’s at the same deformation conditions. Dynamic recrystallization (DRX) is main dynamic softening mechanism in safe processing domain of 6061 alloy, while dynamic recovery (DRV) was main dynamic softening mechanism in WQ1 alloy due to pinning effect of α-Al(MnCr)Si dispersoids. α dispersoids can not only resist DRX but also increase power required for deformation of WQ1 alloy. The microstructure analysis revealed that the flow instability was attributed to the void formation and intermetallic cracking during hot deformation of both alloys.

Formability of Explosive Welded Mg/Al Bimetallic Bar

2016 ◽  
Vol 716 ◽  
pp. 114-120 ◽  
Author(s):  
Sebastian Mróz ◽  
Piotr Szota ◽  
Teresa Bajor ◽  
Andrzej Stefanik
Keyword(s):  
Plastic Deformation ◽  
Strain Rate ◽  
Process Parameters ◽  
Metal Forming ◽  
Explosive Welding ◽  
Physical Modelling ◽  
Main Process ◽  
Compression Tests ◽  
Welding Method

The paper presents the results of physical modelling of the plastic deformation of the Mg/Al bimetallic specimens using the Gleeble 3800 simulator. The plastic deformation of Mg/Al bimetal specimens characterized by the diameter to thickness ratio equal to 1 was tested in compression tests. The aim of this work was determination of the range of parameters as temperature and strain rate that mainly influence on the plastic deformation of Mg/Al bars during metal forming processes. The tests were carried out for temperature range from 300 to 400°C for different strain rate values. The stock was round 22.5 mm-diameter with an Al layer share of 28% Mg/Al bars that had been produced using the explosive welding method. Based on the analysis of the obtained testing results it has been found that one of the main process parameters influencing the plastic deformation the bimetal components is the initial stock temperature and strain rate values.

Fracture of ledeburite steel during hot plastic deformation

1977 ◽  
Vol 19 (5) ◽  
pp. 398-400
Author(s):  
V. P. Nikitin ◽  
Yu. A. Borisov ◽  
S. I. Bulat ◽  
V. V. Zaitsev
Keyword(s):  
Plastic Deformation ◽  
Hot Plastic Deformation

scholarly journals Improvement of pinning in Bi2212-based materials by hot plastic deformation

2006 ◽  
Vol 43 ◽  
pp. 458-461
Author(s):  
R R Daminov ◽  
M Reissner ◽  
M F Imayev ◽  
W Steiner ◽  
M V Makarova ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Hot Plastic Deformation
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