scholarly journals Thermomechanical response of Mg AZ31 at different levels of temperatures and strain rates

2019 ◽  
Vol 304 ◽  
pp. 01025
Author(s):  
Farid Abed ◽  
Wael Abuzaid ◽  
Yomna Morad
Keyword(s):  
True Strain ◽  
Weight Ratio ◽  
High Strength ◽  
Tensile Tests ◽  
Industrial Applications ◽  
Gauge Length ◽  
Image Correlation ◽  
Strain Rates ◽  
Localized Deformation ◽  
The Difference

Magnesium alloys’ mechanical behavior has received increasing attention because of its high strength to weight ratio making them ideal for various industrial applications, such as vehicle components, transportation and aerospace. The objective of this work is to closely investigate the thermo-mechanical properties of magnesium alloy AZ31 at different strain rates and temperatures. Tensile tests are conducted on a 30 mm gauge length MgAZ31 specimens at two quasi-static strain rates (1.11x10−3 s−1 and 0.28 s−1) at a range of temperatures between 25 ºC and 250 ºC. Digital Image Correlation (DIC) system was used to calculate the true strain and provide quantitative assessment of the localized deformation response at high levels of deformation. The stress-strain responses of MgAZ31 show that the yield stress as well as the ultimate stress decreases as temperature increases and strain rate decreases. Moreover, the difference between the yield and ultimate stresses at both strain rates increases rapidly as temperature increases. The material shows a significant increase in ductility as temperature increases while the modulus of elasticity remains independent of change in strain rates.

Hot deformation behavior of low carbon advanced high strength steel (AHSS) microalloyed with boron

2009 ◽  
Vol 1243 ◽  
Author(s):  
I. Mejía ◽  
S. González-Sala ◽  
J.M. Cabrera
Keyword(s):  
High Temperature ◽  
Deformation Behavior ◽  
True Strain ◽  
High Strength ◽  
Tensile Tests ◽  
Strain Rates ◽  
Low Carbon ◽  
Compression Tests ◽  
Advanced High Strength Steel ◽  
Different Temperatures

ABSTRACTThis research work deals the influence of boron content on the high temperature deformation behavior of a low carbon advanced high strength steel (AHSS). For this purpose high temperature tensile and compression tests are carried out at different temperatures and constant true strain rates by using an Instron testing machine equipped with a radiant cylindrical furnace. Tensile tests are carried out at different temperatures (650, 750, 800, 900 and 1000°C) at a constant true strain rate of 0.001 s-1. Uniaxial hot compression tests are also performed over a wide range of temperatures (950, 1000, 1050 and 1100°C) and constant true strain rates (10-3, 10-2 and 10-1 s-1). In general, experimental results of hot tensile tests show an improvement of the hot ductility of the AHSS microalloyed with boron, although poor ductility at low temperatures (650 and 750°C). The fracture surfaces of the AHSS tested at temperatures showing the higher ductility (800, 900 and 1000°C) indicate that the fracture mode is a result of ductile failure, whereas in the region of poor ductility the fracture mode is of the ductile-brittle type failure. On the other hand, experimental results of hot compression tests show that both peak stress and peak strain tend to decrease in the AHSS microalloyed with boron, which indicates that boron generates a sort of solid solution softening effect in similar a way to other interstitial alloying elements in steel. Likewise, hot flow curves of the AHSS microalloyed with boron show an acceleration of the onset of dynamic recrystallization (DRX) and a delay of the recrystallization kinetics. Results are discussed in terms of boron segregation towards austenitic grain boundaries and second phase particles precipitation during plastic deformation and cooling.

scholarly journals Sequential Laser–Mechanical Drilling of Thick Carbon Fibre Reinforced Polymer Composites (CFRP) for Industrial Applications

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2136
Author(s):  
Sharizal Ahmad Sobri ◽  
Robert Heinemann ◽  
David Whitehead
Keyword(s):  
Carbon Fibre ◽  
Polymer Composites ◽  
Weight Ratio ◽  
High Strength ◽  
Industrial Applications ◽  
Fibre Laser ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Thrust And Torque

Carbon fibre reinforced polymer composites (CFRPs) can be costly to manufacture, but they are typically used anywhere a high strength-to-weight ratio and a high steadiness (rigidity) are needed in many industrial applications, particularly in aerospace. Drilling composites with a laser tends to be a feasible method since one of the composite phases is often in the form of a polymer, and polymers in general have a very high absorption coefficient for infrared radiation. The feasibility of sequential laser–mechanical drilling for a thick CFRP is discussed in this article. A 1 kW fibre laser was chosen as a pre-drilling instrument (or initial stage), and mechanical drilling was the final step. The sequential drilling method dropped the overall thrust and torque by an average of 61%, which greatly increased the productivity and reduced the mechanical stress on the cutting tool while also increasing the lifespan of the bit. The sequential drilling (i.e., laser 8 mm and mechanical 8 mm) for both drill bits (i.e., 2- and 3-flute uncoated tungsten carbide) and the laser pre-drilling techniques has demonstrated the highest delamination factor (SFDSR) ratios. A new laser–mechanical sequence drilling technique is thus established, assessed, and tested when thick CFRP composites are drilled.

SYNTHESIS AND CHARACTERISATION OF WOVENROVING GLASS MAT FOR EPOXYCOMPOSITES

2020 ◽  
Vol 15 (4) ◽  
Author(s):  
Mahesh Mallampati ◽  
Sreekanth Mandalapu ◽  
Govidarajulu C
Keyword(s):  
Tensile Strength ◽  
Glass Fiber ◽  
Low Cost ◽  
Weight Ratio ◽  
High Strength ◽  
Hardness Test ◽  
Industrial Applications ◽  
Sem Analysis ◽  
Low Thermal Expansion ◽  
Manufacturing Techniques

The composite materials are replacing the traditional materials because oftheir superior properties such as high tensile strength, low thermal expansion, high strength to weight ratio, low cost, lightweight, high specific modulus, renewability and biodegradability which are the most basic & common attractive features of composites that make them useful for industrial applications. The developments of new materials are on the anvil and are growing day by day. The efforts to produce economically attractive composite components have resulted in several innovative manufacturing techniques currently being used in the composites industry. Generally, composites consist of mainly two phases i.e., matrix and fiber. In this study, woven roving mats (E-glass fiber orientation (-45°/45°,0°/90°, - 45°/45°),UD450GSM)were cut in measured dimensions and a mixture of Epoxy Resin (EPOFINE-556, Density-1.15gm/cm3), Hardener (FINE HARDTM 951, Density- 0.94 gm/cm3) and Acetone [(CH3)2CO, M= 38.08 g/mol] was used to manufacture the glass fiber reinforced epoxy composite by hand lay-up method. Mechanical properties such as tensile strength, SEM analysis, hardness test, density tests are evaluated.

A Mathematical Description for the Stress-Strain Behavior of Annealed 2 1/4 Cr-1 Mo Steel

1976 ◽  
Vol 98 (2) ◽  
pp. 118-125 ◽  
Author(s):  
R. L. Klueh ◽  
T. L. Hebble
Keyword(s):  
Mathematical Description ◽  
Flow Behavior ◽  
True Strain ◽  
Empirical Relationship ◽  
Tensile Tests ◽  
Strain Rates ◽  
Strain Behavior ◽  
Test Conditions ◽  
Wide Range ◽  
Strain Data

We have conducted a detailed series of tensile tests on one heat of annealed 2 1/4 Cr-1 Mo steel over the range 25 to 593°C (75 to 1100°F) and at nominal strain rates of 0.4, 0.04, 0.004, and 0.0004/min. To determine an empirical relationship to represent the flow behavior, we fitted the true-stress true-strain data from these tests to several proposed models. The models fit were those proposed by Hollomon, Ludwik, Ludwigson, and Voce. From a comparison of the standard error of estimate, the Voce equation was concluded to be the best mathematical description of the data under most test conditions and the best single representation over the wide range of test conditions.

Impact of the Harsh Environment on E-Glass Epoxy Composite

2019 ◽  
Author(s):  
Amir Hussain Idrisi ◽  
Abdel-Hamid Ismail Mourad ◽  
Beckry Abdel-Magid ◽  
Mohammad Mozumder ◽  
Yaser Afifi
Keyword(s):  
High Temperature ◽  
Composite Materials ◽  
Oil And Gas ◽  
Epoxy Composite ◽  
Uv Light ◽  
Weight Ratio ◽  
High Strength ◽  
Industrial Applications ◽  
Harsh Environment ◽  
Sustained Loads

Abstract Composite materials are being used in many industrial applications such as automobile, aerospace, marine, oil and gas industries due to their high strength to weight ratio. The long-term effect of sustained loads and environmental factors that include exposure to UV light, temperature, and moisture have been under investigation by many researchers. The major objective of this study is to evaluate the effects of harsh environment (e.g. seawater and high temperature) on the structural properties of E-glass epoxy composite materials. These effects were studied in terms of seawater absorption, permeation of salt and contaminants, chemical and physical bonds at the interface and degradation in mechanical properties. Samples were immersed in seawater at room temperature (23°C), 65°C and 90°C for the duration of 6 months. Results show that seawater absorption increased with immersion time at 23°C and 65°C, whereas the weight of the specimens decreased at 90°C. The moisture causes swelling at 23°C and 65°C and breakdown of chemical bonds between fiber and matrix at 90°C. It is observed that high temperature accelerates the degradation of the E-glass epoxy composite. At 90°C, the tensile strength of E-glass epoxy sharply decreased by 72.92% but no significant change was observed in modulus of elasticity of the composite.

Analysis of Additive Alignment in a 90∘ Elbow Channel

2020 ◽  
Vol 28 (04) ◽  
pp. 2050032
Author(s):  
Hoang Minh Khoa Nguyen ◽  
Dong-Wook Oh
Keyword(s):  
Flow Visualization ◽  
Fiber Type ◽  
Weight Ratio ◽  
High Strength ◽  
Short Fiber ◽  
Industrial Applications ◽  
Injection Molding Process ◽  
Molding Process ◽  
Corner Region ◽  
Liquid Polymer

Short-fiber reinforced polymer composites have been widely used in industrial applications due to high strength-to-weight ratio, versatile manufacturing process, and etc. The alignment of fiber type additives plays an important role in the mechanical properties of a composite material. In this paper, an injection molding process was imitated with a liquid polymer composite flow inside a [Formula: see text] elbow channel. We performed a flow visualization experiment and analyzed the additive alignment of carbon fiber flowing in the polydimethylsiloxane (PDMS) medium. By analyzing the flow visualization images, the angle changes at the corner region of the elbow channel were calculated. At the corner region, the change of passage direction leads to the change of fiber orientation. It was observed that near to the convex region, fibers have angle change values larger than the fibers traveling near to the concave region.

scholarly journals Development of Strain Localization in a Beta-Titanium Alloy Gum Metal Analyzed by Infrared Camera and Digital Image Correlation for Various Strain Rates

Proceedings ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 51
Author(s):  
Elżbieta Pieczyska ◽  
Karol Golasiński ◽  
Michał Maj ◽  
Tadahiko Furuta ◽  
Shigeru Kuramoto
Keyword(s):  
Strain Localization ◽  
Nonlinear Deformation ◽  
Infrared Camera ◽  
High Strength ◽  
Image Correlation ◽  
Strain Rates ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Gum Metal ◽  
Beta Ti Alloy

Effects of thermomechanical couplings were studied in a new beta Ti alloy by IR and DIC techniques. The obtained stress-strain curves confirmed low Young’s modulus and high strength of the alloy. The determined values of yield strength increases and values of elongation till rupture decreases with increasing strain rate. It was found, by using fast and sensitive infrared camera, that the large limit of the Gum Metal reversible nonlinear deformation originates from mechanisms of dissipative nature, probably exothermic stress-induced transition of ” nanodomains.

Hot Deformation Behavior and Microstructure Evolution of Extruded 6069 Al Alloy under Tension

2014 ◽  
Vol 670-671 ◽  
pp. 33-36
Author(s):  
Horng Yu Wu ◽  
Ming Chieh Lin ◽  
Feng Jun Zhu ◽  
Cheng Tao Wu ◽  
Ching Hao Liao ◽  
...  
Keyword(s):  
Dynamic Recovery ◽  
Flow Behavior ◽  
True Strain ◽  
Peak Stress ◽  
Tensile Tests ◽  
Al Alloy ◽  
Strain Rates ◽  
Flow Curves ◽  
Softening Mechanism ◽  
Dynamic Softening

The flow behavior and associated microstructural changes of wrought 6069 Al alloy deformed in tension were analyzed in this work. Tensile tests were conducted on an extruded tube with a thickness of 1.6 mm in the temperature range of 300–500 oC, with initial strain rates from 0.001 to 0.1 s-1. The true stress–true strain curves exhibited a peak stress at a critical strain. The overall level of the flow curve increased when the strain rate was increased and/or the temperature was decreased. The flow curves exhibited a typical flow behavior with dynamic softening and showed that the softening degree after reaching the peak stress was dependent on the deformation conditions. This could be related to the softening mechanism. The main softening mechanism of the alloy was dynamic recovery (DRV) at low temperatures; dynamic recrystallization (DRX) occurred as deformed at high temperatures.

Development of a Pneumatic Bulge Test for High Temperatures and Controlled Strain Rates

2014 ◽  
Vol 1018 ◽  
pp. 245-252 ◽  
Author(s):  
Alexander Braun ◽  
Johannes Storz ◽  
Markus Bambach ◽  
Gerhard Hirt
Keyword(s):  
Finite Element ◽  
Hot Stamping ◽  
High Strength ◽  
Tensile Tests ◽  
Finite Element Simulations ◽  
Bulge Test ◽  
Strain Rates ◽  
Hot Gas ◽  
Pneumatic Bulge Test ◽  
Simulation Input

Due to new material concepts (e.g. boron-manganese steels), hot stamping of sheet metal parts has emerged in order to produce high strength components. Thereby, the design of hot stamping processes by means of finite element simulations requires information about the thermo-mechanical material behaviour up to high strain levels at various temperatures as simulation input. It is known that hot tensile tests are only evaluable until low strain levels. Therefore, a hot gas bulge test for temperatures in the range of 600 °C to 900 °C and strain rates up to 1/s is being developed. In order to design such a hot gas bulge test, the requirements (e.g. forming pressure) are estimated by finite element simulations. The result is a test bench, which already enables a pneumatic forming of specimens at room temperature and pressures up to 200 bar without any unexpected side effects.

scholarly journals Numerical Modelling and Analytical Comparison of Delamination during Cryogenic Drilling of CFRP

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3995
Author(s):  
Arunachalam S. S. Balan ◽  
Chidambaram Kannan ◽  
Kunj Jain ◽  
Sohini Chakraborty ◽  
Siddharth Joshi ◽  
...  
Keyword(s):  
Numerical Models ◽  
Weight Ratio ◽  
High Strength ◽  
Industrial Applications ◽  
Reinforced Polymers ◽  
Carbon Fibre Reinforced Polymers ◽  
Subsequent Effect ◽  
Drilling Conditions ◽  
Machining Operations ◽  
Innovative Techniques

Carbon-Fibre-Reinforced Polymers (CFRPs) have seen a steady rise in modern industrial applications due to their high strength-to-weight ratio and corrosion resistance. However, their potential is being hindered by delamination which is induced on them during machining operations. This has led to the adoption of new and innovative techniques like cryogenic-assisted machining which could potentially help reduce delamination. This study is aimed at investigating the effect of cryogenic conditions on achieving better hole quality with reduced delamination. In this paper, the numerical analysis of the drilling of CFRP composites is presented. Drilling tests were performed experimentally for validation purposes. The effects of cooling conditions and their subsequent effect on the thrust force and delamination were evaluated using ABAQUS/CAE. The numerical models and experimental results both demonstrated a significant reduction in the delamination factor in CFRP under cryogenic drilling conditions.

Sign in / Sign up

Export Citation Format

Share Document