The main objective of the present study was to investigate the effect of Mg/Si precipitates on the hot-compression response of Al-Mg-Si alloy and further inspect the influence of compression temperatures and Mg/Si precipitates on microstructural changes. The processing maps were drawn using the dynamic materials model approach. To validate the processing maps, metallurgical factors of different regions of processing map were investigated using differential scanning calorimetry (DSC) and electron back-scattered diffraction. The influence of strain rate on the flow stresses of Al-Mg-Si alloy is not consistent with the traditional results after compression from 100 to 250 °C, due to the strain ageing produced by the Mg/Si precipitates. The DSC study reveals that no Mg/Si precipitate evolved during the compression test after compressing beyond 250 °C. The processing maps (drawn at 0.1 true strain to 0.6 true strain) and metallurgical factors (high-angle grain boundaries or dynamic recrystallized grains) indicated that hot-compression efficiency of Al-Mg-Si alloy is significantly improved after compression beyond 250 °C, because no Mg/Si precipitates evolved. © 2019, ASM International.

Rengaswamy Jayaganthan

Department of Engineering Design

Aluminum alloys

Compression testing

Differential scanning calorimetry

Grain boundaries

Metallurgy

microstructure

Precipitates

Silicon alloys

Strain rate

AL-MG-SI ALLOYS

COMPRESSION EFFICIENCY

COMPRESSION TEMPERATURE

DYNAMIC MATERIALS MODEL

Electron back-scattered diffraction

High angle grain boundaries

Microstructural changes

Recrystallized grains

Magnesium alloys

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Materials Engineering and Performance

In the present work, ultrafine grained Al 6082 alloy was produced by cryorolling (CR), room temperature rolling (RTR), CR + annealing (CR + AN) at 200 °C and RTR + annealing (RTN + AN) at 200 °C processes to study the effects of metallurgical factors (ultrafine grain structure, precipitates and secondary phase particles) on its low cycle fatigue behavior. Various characterization techniques such as the transmission electron microscopy, electron back scattered diffraction, scanning electron microscopy and differential scanning calorimetry were used to investigate the low cycle fatigue (LCF) behavior of the 6082 Al alloy. It was observed that the sample produced via CR + AN exhibits the highest LCF life when compared to the other samples investigated. The improvement in the LCF life of the 6082 Al alloy after CR + AN is attributed to the presence of small sized Si-rich precipitates, secondary phase particles, sub grains formation (200–400 nm) and high stored energy (32.16 × 10−4 J/mol). © 2018 Elsevier Ltd

International Journal of Fatigue

The influence of metallurgical factors on low cycle fatigue behavior of ultra-fine grained 6082 Al alloy

The influence of cryorolling (CR), room temperature rolling (RTR) and post annealing on precipitation, microstructural evolution (recovery, recrystallisation and grain growth), mechanical and corrosion behavior, was investigated in the present work. The precipitation kinetics and microstructural morphology of CR, RTR, and post annealed samples were investigated by differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and electron back scattered diffraction (EBSD) to elucidate the observed mechanical properties. After annealing at 200 °C, UTS and hardness of CR samples (345 MPa and HV 127) were improved as compared to RTR samples (320 MPa and HV 115). The increase in hardness and UTS of CR samples after annealing at 200 °C was due to precipitation of β″ from Al matrix, which imparted higher Zener drag effect as compared to RTR samples. The improvement in corrosion and pitting potentials was observed for CR samples (−1.321 V and −700 mV) as compared to RTR samples (−1.335 V and −710 mV). In CR samples, heavy dislocation density and dissolution of Mg4Al3Si4-precipitates in the Al matrix have improved corrosion resistance of the alloy through formation of protective passive layer and suppression of galvanic cell, respectively. © 2017 The Nonferrous Metals Society of China

Transactions of Nonferrous Metals Society of China (English Edition)

Effect of deformation temperature on precipitation, microstructural evolution, mechanical and corrosion behavior of 6082 Al alloy

In the present work, the effect of grain boundary misorientation, deformation temperature and AlFeMnSi-phase on fatigue behavior of 6082 Al has been investigated. The 6082 Al alloy has been subjected to cryorolling followed by warm rolling at 100 °C–250 °C. The fatigue test of the processed alloy has been performed at stress ratio (R) of zero with different stress amplitude of 25, 50, 60, 70, 80, 90, and 110 MPa. The deformed alloy and fracture surface was characterized by using XRD, DSC, SEM and EDS to elucidate the role of AlFeMnSi-phase and Mg2Si-precipitates on fatigue life of the alloy. Cryorolling followed by Warm rolling (CR + WR) 6082 Al alloy rolled at 100 °C temperature showed higher dislocation density compared to other processed sample. The small size of AlFeMnSi-phase and Mg2Si-precipitates, high dislocation density and low angle grain boundaries had improved the fatigue life of 6082 Al alloy as observed in the present work. © 2017 Elsevier Inc.

Materials Characterization

Effect of grain boundary misorientaton, deformation temperature and AlFeMnSi-phase on fatigue life of 6082 Al alloy

The hot deformation behavior of alloy 617 has been studied by performing hot compression in a range of temperatures (1173-1473 K) and strain rates (0.001-10 s-1). The peak flow stress found to increase with Zener-Hollomon parameter (Z) following a hyperbolic-sine function relationship whereas peak strain followed power-law type relationship with Z. The average activation energy for the entire hot deformation domain was estimated to be 481 kJ mol-1. The experimental stress-strain data has been used to develop processing map employing dynamic material model. The material exhibits a wide stable domain below 0.1 s-1 spanning over 1250-1473 K, with a peak efficiency of ~45%. Based on the processing map and subsequent microstructural observation, the optimum hot deformation domain of alloy 617 is identified as 1323-1423 K and 0.001-0.1 s-1. Furthermore, microstructural observation alone has revealed that a significant DRX with grain refinement could also be obtained at high temperature (&gt;1373 K) and high strain rate (&gt;1 s-1) domain although processing map has marked this region as unstable domain. © 2016 Elsevier B.V.

Materials Science and Engineering A

Characterization of hot deformation behavior of alloy 617 through kinetic analysis, dynamic material modeling and microstructural studies

The mechanical and corrosion behavior of Al alloy 6082-T6 subjected to solution heat treating condition at temperatures varying from 400 to 600 °C and soaking times of 3–24 h have been investigated. Solution heat treating at 550 °C for 24 h led to the dissolution of the Mg2Si and AlSi6Mg3Fe precipitates into the matrix, and the Al12(FeMn)3Si2 phase transformed into Al85(Fe0.28Mn0.72)14Si phase. The solution-treated alloy showed equiaxed grain morphology with an average grain size of 85.7 µm. Increasing the solution heat treating temperature beyond 550 °C caused a reduction in corrosion resistance of the alloy. The pitting potential increased due to the presence of the anodic phase Mg2Si (dissolved at 550 °C) in Al matrix and it decreased with the formation of cathodic phases such as AlSi6Mg3Fe and Al12(FeMn)3Si2 (dissolved at 550 °C/24 h) in the alloy. General corrosion resistance of the alloy increased with decreasing Mg2Si concentration in the Al matrix. The optimum solution heat treating condition of 550 °C for 24 h resulted in an improvement in hardness (63 VHN), ultimate tensile strength (UTS—208 MPa), and pitting potential (−675 mV) and uniform corrosion potential (−1.255 mV) of 6082 Al alloy. © 2015, Springer Science+Business Media New York and ASM International.

Metallography, Microstructure, and Analysis

Effect of Solution Treatment on Mechanical and Corrosion Behaviors of 6082-T6 Al Alloy

Hot-Compression Response of Solution-Treated Al-Mg-Si Alloy

Journal	Data powered by TypesetJournal of Materials Engineering and Performance
Publisher	Data powered by TypesetSpringer
ISSN	10599495
Open Access	No