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.

Effect of Heating Rates and Loading Rates on Mechanical Behaviors of Magnesium Alloy

2011 ◽  
Vol 686 ◽  
pp. 63-67
Author(s):  
Bin Chen ◽  
Ji Luo ◽  
Quan Yuan ◽  
Ding Fei Zhang ◽  
Guo Zheng Quan
Keyword(s):  
Magnesium Alloy ◽  
Heating Rate ◽  
Mechanical Response ◽  
Testing System ◽  
High Heating Rate ◽  
Mechanical Behaviors ◽  
Heating Rates ◽  
Loading Rates ◽  
High Heating ◽  
Strength And Plasticity

The mechanical response and failure of the specimens of magnesium alloy AZ61 with different heating rates (HR) and loading rates (LR) were investigated by a Gleeble-1500 thermal-mechanical material testing system. It was found that heating rate has markedly effect on the strength and plasticity of the specimens. The higher the heating rate is, the lower the strength and the smaller of the plasticity of the specimens will be. There is the relatively small effect of the loading rates on the strength and plasticity of the specimens. The metallographs of the failed specimens were also observed. It shows that there are many microvoids in the specimens near the fracture sections. These microvoids may come from the local thermal and stress inconsistency under high heating rate and loading rates and degrade the strength and plasticity of the specimens.

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.

Critical damage value of AZ31B magnesium alloy with different temperatures and strain rates

Rare Metals ◽  
2015 ◽  
Author(s):  
Jing-Ren Dong ◽  
Ding-Fei Zhang ◽  
Yu-Feng Dong ◽  
Fu-Sheng Pan ◽  
Sen-Sen Chai
Keyword(s):  
Magnesium Alloy ◽  
Strain Rates ◽  
Az31b Magnesium Alloy ◽  
Different Temperatures ◽  
Critical Damage

scholarly journals XPS and Electron Microscopy Study of Oxide-Scale Evolution on Ignition Resistant Mg-3Ca Alloy at Low and High Heating Rates

2020 ◽  
Vol 1 ◽  
Author(s):  
L. A. Villegas-Armenta ◽  
R. A. L. Drew ◽  
M. O. Pekguleryuz
Keyword(s):  
Oxide Scale ◽  
Heating Rate ◽  
Photoelectron Spectroscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
High Heating Rate ◽  
Heating Rates ◽  
Oxide Interface ◽  
Protective Oxide ◽  
High Heating

AbstractEarlier work by the authors suggested that the formation of molten eutectic regions in Mg-Ca binary alloys caused a discrepancy in ignition temperature when different heating rates are used. This effect was observed for alloys where Ca content is greater than 1 wt%. In this work, the effect of two heating rates (25 °C/min and 45 °C/min) on the ignition resistance of Mg-3Ca is evaluated in terms of oxide growth using X-ray Photoelectron Spectroscopy. It is found that the molten eutectic regions develop a thin oxide scale of ~100 nm rich in Ca at either heating rate. The results prove that under the high heating rate, solid intermetallics are oxidized forming CaO nodules at the metal/oxide interface that eventually contribute to the formation of a thick and non-protective oxide scale in the liquid state.

scholarly journals Effects of Heating Rate on Formation of Globular and Acicular Austenite during Reversion from Martensite

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 266 ◽  
Author(s):  
Xianguang Zhang ◽  
Goro Miyamoto ◽  
Yuki Toji ◽  
Tadashi Furuhara
Keyword(s):  
Heating Rate ◽  
High Temperatures ◽  
The Other ◽  
Growth Mode ◽  
High Heating Rate ◽  
Heating Rates ◽  
Other Hand ◽  
High Heating ◽  
Martensite Matrix

The effects of heating rate on the formation of acicular and globular austenite during reversion from martensite in Fe–2Mn–1.5Si–0.3C alloy have been investigated. It was found that a low heating rate enhanced the formation of acicular austenite, while a high heating rate favored the formation of globular austenite. The growth of acicular γ was accompanied by the partitioning of Mn and Si, while the growth of globular γ was partitionless. DICTRA simulation revealed that there was a transition in growth mode from partitioning to partitionless for the globular austenite with an increase in temperature at high heating rate. High heating rates promoted a reversion that occurred at high temperatures, which made the partitionless growth of globular austenite occur more easily. On the other hand, the severer Mn enrichment into austenite at low heating rate caused Mn depletion in the martensite matrix, which decelerated the reversion kinetics in the later stage and suppressed the formation of globular austenite.

Deformation Behaviour of Martensite in a Low-Carbon Dual-Phase Steel

2006 ◽  
Vol 15-17 ◽  
pp. 774-779 ◽  
Author(s):  
M. Mazinani ◽  
Warren J. Poole
Keyword(s):  
Dual Phase Steel ◽  
Volume Fraction ◽  
Deformation Behaviour ◽  
Dual Phase ◽  
Low Carbon ◽  
Heating Rates ◽  
Dp Steel ◽  
Martensite Content ◽  
High Heating ◽  
Different Temperatures

The deformation behaviour of martensite and its effect on tensile properties of a lowcarbon dual-phase (DP) steel were investigated. DP steel samples with different martensite contents and morphologies were produced after intercritical annealing at different temperatures using low and high heating rates. Two distinct martensite morphologies were obtained for low and high heating rates. The investigated steel showed the unusual results that the true fracture stress and strain were found to increase with the martensite volume fraction. The plastic deformation of martensite was considered to be responsible for these results. Experimentally, it was observed that the martensite in DP steels with greater than 25-30% martensite can deform plastically during tensile straining. Finally, the effect of tempering on the martensite plasticity was also evaluated. It was found that the tempering process and an increase in the martensite content have a similar effect on promoting martensite plasticity.

scholarly journals Microstructure Evolution of Selective Laser Melted Inconel 718: Influence of High Heating Rates

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 587 ◽  
Author(s):  
Seyedmohammad Tabaie ◽  
Farhad Rézaï-Aria ◽  
Mohammad Jahazi
Keyword(s):  
Heating Rate ◽  
Inconel 718 ◽  
Microstructural Analysis ◽  
Secondary Phases ◽  
Heating Rates ◽  
Laser Melting ◽  
Microstructural Characteristics ◽  
High Heating ◽  
In718 Superalloy ◽  
Confocal And Electron Microscopy

Inconel 718 (IN718) superalloy samples fabricated by selective laser melting (SLM) were submitted to different heating cycles and their microstructural characteristics were investigated. The selected heating rates, ranging from 10 °C/min to 400 °C/s, represent different regions in the heat-affected zone (HAZ) of welded additively manufactured specimens. A combination of differential thermal analysis (DTA), high-resolution dilatometry, as well as laser confocal and electron microscopy were used to study the precipitation and dissolution of the secondary phases and microstructural features. For this purpose, the microstructure of the additively manufactured specimen was investigated from the bottom, in contact with the support, to the top surface. The results showed that the dissolution of γ″ and δ phases were delayed under high heating rates and shifted to higher temperatures. Microstructural analysis revealed that the Laves phase at the interdendritic regions was decomposed in specific zones near the surface of the samples. It was determined that the thickness and area fraction of these zones were inversely related to the applied heating rate. A possible mechanism based on the influence of heating rate on Nb diffusion in the interdendritic regions and core of the dendrites is proposed to interpret the observed changes in the microstructure.

The Effect of Heating Rate and Temperature on Mechanical and Microstructure Properties of β-TCP by Microwave Sintering

2017 ◽  
Vol 264 ◽  
pp. 91-94
Author(s):  
Chuthathip Mangkonsu ◽  
Ahmad Fauzi Mohd Noor ◽  
Banhan Lila ◽  
Kawashita Masakazu
Keyword(s):  
Heating Rate ◽  
Microwave Sintering ◽  
Sintered Sample ◽  
Mechanical Analysis ◽  
Heating Rates ◽  
Microwave Furnace ◽  
Different Temperatures

This aim of this work was to evaluate the influences of the heating rates and sintering temperatures for sintering β-TCP by microwave furnace. In the first part of work, the heating rates used for sintering β-TCP were including 10, 20, 30 and 40°C/min. Results from physical and mechanical analysis shown that the optimum properties were shown by samples produced at heating rate of 30°C/min. In the second part of the study, the heating rate of 30°C/min was continuing used to sintering samples by different temperatures (1200°C, 1250°C and 1300°C). The sintered sample at 1200°C presented the optimum properties in the physical and mechanical analysis. Finally, the sintered samples by the heating rate 30°C/min at 1200°C were in immersed in SBF to confirm the bioactivity property of β-TCP.

Experiments on Thermosyphon Loops for Low-Temperature Waste-Heat Recovery

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
Koji Matsubara ◽  
Suguru Tachikawa ◽  
Itaru Kourakata ◽  
Yusaku Matsudaira
Keyword(s):  
Thermal Resistance ◽  
Heating Rate ◽  
Waste Heat ◽  
Volume Ratio ◽  
Pressure Head ◽  
Working Fluid ◽  
Heating Rates ◽  
Different Temperatures ◽  
Flow Circulation ◽  
Flow Map

We tested a thermosyphon loop with water as the working fluid using heating rates between 100 W and 400 W. Four kinds of core blocks were installed in the evaporator and tested: a hollow block, and blocks with narrow holes: Φ 2.2 mm × 90; Φ 2.5 mm × 55; and Φ 4.0 mm × 30. The temperature distribution indicated stable flow circulation inside the thermosyphon at low volume ratios but was unstable when the volume ratio was increased higher than 30%. The characteristics of the flow pattern are summarized as a flow map showing the heating rate versus the volume ratio. The recovered heat and the thermal resistance of the thermosyphon loop were clearly improved by using the core blocks with narrow holes instead of hollow blocks for the treated volume ratios from 20% to 80%. The thermal resistance increased when the volume ratio reached high values, suggesting that the effects from the abnormality of the flow circulation affected thermal resistance. The velocity of the gas stream in the thermosyphon was estimated by assuming an isothermal state, and it is diagrammed showing the heating rate at different temperatures. The current experiment of the thermosyphon loop is plotted in this diagram, which indicates the need for a wide margin due to the limitations of the sonic velocity and the pressure head at the full height of the heat pipe.

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