scholarly journals Physical Modelling of Metal Forming of Bars Made of Magnesium Alloys (AZ61) / Fizyczne Modelowanie Warunków Przeróbki Plastycznej Prętów Ze Stopów Magnezu (AZ61)

2015 ◽  
Vol 60 (4) ◽  
pp. 3007-3010
Author(s):  
T. Bajor ◽  
H. Dyja ◽  
K. Laber
Keyword(s):  
Magnesium Alloy ◽  
Strain Rate ◽  
Yield Stress ◽  
Magnesium Alloys ◽  
Research Methodology ◽  
Metal Forming ◽  
Physical Modelling ◽  
Testing System ◽  
Different Temperatures ◽  
Metallurgical Processes

This study presents the results of physical modelling of the processes of metal forming of bars made of magnesium alloy (AZ61) obtained using two research methodologies. The study employed the Gleeble 3800 testing system for simulation of metallurgical processes and a torsion plastometer. Depending on the research methodology used, the examinations were carried out in the temperature range of 200 ÷ 400°C and strain rate of (0.1 - 10 s-1). The results obtained in the study were used to determine the value of yield stress for AZ61 alloy for different strain procedures and different temperatures and strain ratios.

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.

Morphology of Edge Cracks of Rolled Magnesium Alloy Sheet

2014 ◽  
Vol 922 ◽  
pp. 469-474 ◽  
Author(s):  
Sho Manabe ◽  
Hiroshi Utsunomiya ◽  
Tetsuo Sakai ◽  
Ryo Matsumoto
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
High Speed ◽  
Heating Temperature ◽  
Thin Sheet ◽  
Contact Length ◽  
Alloy Sheet ◽  
Different Temperatures ◽  
Edge Cracks ◽  
Critical Reduction

Magnesium alloys show low deformability at low temperature because of hcp structure and inactiveness of basal slip. Manufacturing of thin sheet is difficult in industries. Some approaches, such as small-draft multi-pass rolling, intermediate annealing, isothermal rolling and high-speed rolling were proposed to overcome the deformability. However, small edge cracks are still formed on the sheet. In this study, rolling speed of 1000m/min was employed to warm-roll AZ31B magnesium alloy in a single pass at different temperatures. The edge cracks formed after the rolling were classified into three main groups: minor, regular and zigzag edge cracks. ‘Crack contact length’ are introduced to explain the morphology of edge cracks. The results show that the critical reduction for crack initiation depends on the pre-heating temperature. The spacing between edge cracks increases linearly with the crack contact length regardless of roll diameter, speed and reduction. It is suggested that this approach is useful to understand the formation mechanism of edge cracks and to evaluate the rollability of magnesium alloys.

scholarly journals Plastometric tests for plasticine as physical modelling material

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Łukasz Wójcik ◽  
Konrad Lis ◽  
Zbigniew Pater
Keyword(s):  
Strain Rate ◽  
Temperature Change ◽  
Compression Test ◽  
Constitutive Equations ◽  
Metal Forming ◽  
Material Flow ◽  
Physical Modelling ◽  
Flow Curves ◽  
Black And White ◽  
White Colour

Abstract This paper presents results of plastometric tests for plasticine, used as material for physical modelling of metal forming processes. The test was conducted by means of compressing by flat dies of cylindrical billets at various temperatures. The aim of the conducted research was comparison of yield stresses and course of material flow curves. Tests were made for plasticine in black and white colour. On the basis of the obtained experimental results, the influence of forming parameters change on flow curves course was determined. Sensitivity of yield stresses change in function of material deformation, caused by forging temperature change within the scope of 0&C ÷ 20&C and differentiation of strain rate for ˙ɛ = 0.563; ˙ɛ = 0.0563; ˙ɛ = 0.0056s−1,was evaluated. Experimental curves obtained in compression test were described by constitutive equations. On the basis of the obtained results the function which most favourably describes flow curves was chosen.

Ultimate Strength and Plasticity of Magnesium Alloy under Different Temperatures and Strain Rates

2011 ◽  
Vol 686 ◽  
pp. 225-229
Author(s):  
Bin Chen ◽  
Da Gang Yin ◽  
Quan Yuan ◽  
Ji Luo ◽  
Ding Fei Zhang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Ultimate Strength ◽  
Fracture Stress ◽  
Tensile Tests ◽  
Material Testing ◽  
Testing System ◽  
Strain Rates ◽  
Az61 Magnesium Alloy ◽  
Different Temperatures ◽  
Strength And Plasticity

A series of tensile tests of AZ61 magnesium alloy were conducted using Gleeble-1500 thermal-mechanical material testing system to learn the effect of the test temperatures and strain rates on the mechanical properties of the alloy. It is indicated that the higher the temperature, the lower the ultimate strength and fracture stress, and the larger the plasticity. It is also revealed that the larger the strain rate is, the higher the ultimate strength of the specimens will be, and the larger the plasticity of the specimens will be. The failure mechanism of the material under high temperature was also analyzed based on the fracture observation. It shows that the high temperatures will induce microvoids or microflaws in the material.

Superplastic Behaviour of AZ61-F Magnesium Composite Materials

2017 ◽  
Vol 36 (3) ◽  
pp. 279-283 ◽  
Author(s):  
Michal Besterci ◽  
Katarína Sülleiová ◽  
Oksana Velgosová ◽  
Beáta Balloková ◽  
S.-J. Huang
Keyword(s):  
Grain Size ◽  
Composite Materials ◽  
Strain Rate ◽  
Magnesium Alloys ◽  
Equal Channel Angular Pressing ◽  
Strain Rates ◽  
Maximum Strain ◽  
Plastic Deformations ◽  
Angular Pressing ◽  
Different Temperatures

AbstractDeformation of AZ61-F magnesium alloys with 1 wt % of Al2O3phase was tested at different temperatures and different strain rates. It was shown that at temperatures 473–523 K and the highest strain rate applied from 1×10–2s–1to 1×10–4s–1, a significant ductility growth was observed. The grain size of 0.6–0.8 μm was reached by severe plastic deformations by means of equal channel angular pressing (ECAP). Secondary Mg17Al12and Al2O3phases were identified. Maximum strain was gained at temperature of 473 K and strain rate of 1×10–4s–1.

Molecular Dynamics Study on Uniaxial Compression Transformation of Magnesium Alloy

NANO ◽  
2021 ◽  
pp. 2150118
Author(s):  
Qianhua Yang ◽  
Chun Xue ◽  
Zhibing Chu ◽  
Yugui Li ◽  
Lifeng Ma
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Phase Transformation ◽  
Magnesium Alloy ◽  
Strain Rate ◽  
Uniaxial Compression ◽  
Dynamics Simulation ◽  
Basic Knowledge ◽  
Transformation Mechanism ◽  
Different Temperatures

As a new method of calculating materials, molecular dynamics simulation can effectively reproduce the mechanical behavior of materials at the atomic level. In this paper, through the construction of the AZ31 magnesium alloy model, the uniaxial compression deformation of magnesium alloy at different temperatures and strain rate is simulated by molecular dynamics method, the mechanical properties and microstructure changes of magnesium alloy are analyzed, the phase transformation mechanism of magnesium alloy under uniaxial compression is revealed, and the effects of temperature and strain rate on the phase transformation of magnesium alloy are explored at the nanometer scale. It provides a theoretical basis and necessary basic knowledge for the design and development of Mg-based nanostructured alloys with excellent mechanical properties.

Effects of Strain Rate and Heat Treatment on the Tensile Property of 1Mn1Zn4Y Magnesium Alloy

2011 ◽  
Vol 311-313 ◽  
pp. 583-586
Author(s):  
Xiu Zhi Zhang ◽  
Ying Jie Li ◽  
Yi Shuai Zhang
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Grain Size ◽  
Magnesium Alloy ◽  
Strain Rate ◽  
Magnesium Alloys ◽  
Tensile Property ◽  
Tensile Tests ◽  
Second Phase ◽  
Dispersed Particles

In this paper, the effect of heat treatment and strain rate on the tensile property of extruding magnesium alloys 1Mn1Zn4Y is studied by using tensile tests. It can be concluded that because the grain size of the sample with solid solution (T4) is coarser than that of the sample without heat treatment，the elongation and the strength of the specimen treated with solid solution are lower. However, owing to many fine and dispersed particles of the second phase precipitated from the solid solution, the strength of sample treated with solid solution + aging (T6) is the highest.

scholarly journals Constitutive Equations of Yield Stress Sensitivity to Strain Rate of Metals: A Comparative Study

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Ammar A. Al Salahi ◽  
Ramzi Othman
Keyword(s):  
Strain Rate ◽  
Yield Stress ◽  
Constitutive Equations ◽  
Optimization Problem ◽  
Rate Sensitivity ◽  
Stress Sensitivity ◽  
Metallic Materials ◽  
Steel Material ◽  
Different Temperatures ◽  
Eyring Equation

Several constitutive equations have proposed to model the strain rate sensitivity of metals to strain rate. This paper presents a comparative of six equations reported in the open literature. All equations are used to fit the yield stress of three copper materials and one steel material at two different temperatures. A specific cost function and an optimization problem are defined. The authors recommend the use of the Cowper-Symonds equation or a modified-Eyring equation as both of them fit well the experimental data while using only three material constants. A modified flow stress Johnson-Cook equation is then proposed for metallic materials.

scholarly journals Tensile Properties of Die-Cast Magnesium Alloy AZ91D at High Strain Rates in the Range between 300 s-1 and 1500 s-1

2010 ◽  
Vol 24-25 ◽  
pp. 325-330 ◽  
Author(s):  
Iram Raza Ahmad ◽  
Dong Wei Shu
Keyword(s):  
Tensile Strength ◽  
Magnesium Alloy ◽  
Strain Rate ◽  
Magnesium Alloys ◽  
Dynamic Behaviour ◽  
High Strain ◽  
Strain Rates ◽  
Alloy Az91d ◽  
Cast Magnesium Alloy ◽  
Cast Magnesium

Magnesium alloys have been increasingly used in the automobile, aerospace and communication industries due to their low density, high strength to weight ratio, good impact resistance and castability. Magnesium alloys, previously not used in load bearing components and structural parts are strongly being considered for use in such applications. Impact events in vehicles and airplanes as well as developments in weaponry and high speed metal working are all characterized by high rates of loading. Understanding of the dynamic behaviour of materials is critical for proper design and use in different applications. In the current study, a cast magnesium alloy AZ91D has been investigated at quasi-static and higher strain rates in the range between 300 s-1 and 1500 s-1. The INSTRON machine was used to perform the quasi-static tests. High strain rate tests have been performed using the Split Hopkinson Tensile Bar (SHTB), a very useful and widely used tool to study the dynamic behaviour of variety of engineering materials. The results of a tensile testing indicate that the tensile properties including yield strength (YS), ultimate tensile strength (UTS) and the elongation at fracture (Ef) are affected by the strain rate variation. Higher stresses are associated with higher strain rates. The alloy AZ91D displays approximately 45% higher tensile stresses at an average strain rate of approximately 1215/s than at quasi-static strain rate. The dependence of the yield stress and tensile strength on the strain rate in the range of high strain rate above 1000 s-1 is larger than that at lower strain rates. The alloy AZ91D is observed to be more strain rate sensitive for strain rate higher than 1000 s-1. A decrease in the strain rate sensitivity is also observed with the increasing strain in the specimen. It is observed that the hardening behaviour of the alloy is affected with increasing the strain rate. At high strain rates, the fracture of magnesium alloy AZ91D tends to transit from ductile to brittle.

Mechanical Behaviors of Magnesium Alloy AZ61 under Different Strain Rates and Heating Rates

2011 ◽  
Vol 686 ◽  
pp. 208-212
Author(s):  
Bin Chen ◽  
Quan Yuan ◽  
Ji Luo ◽  
Ding Fei Zhang ◽  
Guo Zheng Quan
Keyword(s):  
Magnesium Alloy ◽  
Heating Rate ◽  
Ultimate Strength ◽  
Testing System ◽  
Strain Rates ◽  
Mechanical Behaviors ◽  
Heating Rates ◽  
High Heating ◽  
Different Temperatures ◽  
Fracture Section

The effects of strain rate (SR) and heating rate (HR) on the mechanical behaviors of the tensile specimens of magnesium alloy AZ61 were experimentally investigated using a Gleeble-1500 thermal-mechanical material testing system. It showed that the higher the temperature is, the lower the ultimate strength of the specimens will be. The higher the heating rate is, the higher the ultimate strength of the specimens will be. The metallurgraphs of the fracture section of the specimens were also experimentally investigated for exploring their failure mechanism under different temperatures and heating rates. It showed that the high temperatures and high heating rates will induce microvoids in the specimens. The microvoids make the specimens failure under relative low loads.

Sign in / Sign up

Export Citation Format

Share Document