Recrystallization Behaviour of Plane Strain Deformed Al-Mn-Mg-Sc-Zr Alloy

2015 ◽  
Vol 231 ◽  
pp. 1-10
Author(s):  
Magdalena M. Miszczyk ◽  
Henryk Paul
Keyword(s):  
Plane Strain ◽  
Second Phase ◽  
Electron Backscattered Diffraction ◽  
Thermally Activated ◽  
Resolution Electron ◽  
Second Phase Particles ◽  
Continuous Recrystallization ◽  
Misorientation Angles ◽  
Scanning Electron ◽  
Zr Alloy

Early stages of recrystallization were observed for the Al-Mn-Mg-Zr(Sc) aluminium alloy containing a fine second phase particles. The samples were plane strain compressed to 40%, 60% and 83% and then annealed. The processes of the recovery and the nucleation of new grains were analysed with the use of scanning electron microscopy equipped with a high resolution electron backscattered diffraction facility. The deformed alloy contained a structure of flat grains situated parallel to the compression plane. After annealing, the structure coarsened. However, the growth of the new grains was strongly hindered by the presence of particles, and the elongated shape of the deformed grains was conserved up to the later stages of recrystallization. In the case ofthe samples deformed up to 40%, the structure was transformed by the mechanism of continuous recrystallization, whereas, in the case of the samples deformed up to 60% or 83%, both mechanisms- of continuous and discontinuous recrystallization - were valid. A particular role in the rise of thenuclei and the structure spheroidization is attributed to the thermally activated migration of the low-angle grain boundaries and the movement of the dislocations stored inside the cells. This leads to an increase of the misorientation angles across the pre-existing low-angle boundaries.

Effect of Calcium and Magnesium Addition on the Inclusions Distribution in the Cast Microstructure of HSLA Steel

2014 ◽  
Vol 685 ◽  
pp. 27-30
Author(s):  
Yan Liu ◽  
Kai Wang ◽  
Yang Liu ◽  
Jian Ming Wang
Keyword(s):  
Hsla Steel ◽  
New Technology ◽  
High Heat ◽  
Second Phase ◽  
Second Phase Particles ◽  
High Heat Input ◽  
Calcium And Magnesium ◽  
Cast Microstructure ◽  
Zr Alloy ◽  
Magnesium Addition

A new technology to obtain a fine-structured and high-toughness HAZ of HSLA steel for high heat input welding is developed using metallurgical thermodynamics, physical chemistry of metallurgy and material processing methods synthetically in this study. A kind of HSLA steel is designed in this experiment. The thermal stability second phase particles which would not be dissolved or aggregated at high temperature will be expected by means of adding calcium and magnesium into the steel in the form of Si-Ca alloy and Mg-Zr alloy, respectively. The effect of calcium and magnesium addition on the morphology and distribution of the inclusions in the cast microstructure of HSLA steel was analysed. The results show that the distribution of the inclusions is more dense and uniform with respect to the raw steel, and the size of the inclusions is smaller than the ones in the raw steel after adding Ca and Mg elements. Ca and Mg elements can accelerate the nucleation of the inclusions. The nucleation rate of the Mg element is relatively higher. The number of the inclusions in the adding Mg steel decrease more slowly relative to the adding Ca steel with the extension of the steelmaking time.

Transmission electron microscopy observation of second-phase particles in β–Si3N4 grains

1999 ◽  
Vol 14 (7) ◽  
pp. 2959-2965 ◽  
Author(s):  
Naoto Hirosaki ◽  
Tomohiro Saito ◽  
Fumio Munakata ◽  
Yoshio Akimune ◽  
Yuichi Ikuhara
Keyword(s):  
Electron Microscopy ◽  
Silicon Nitride ◽  
Heat Treating ◽  
High Resolution Electron Microscopy ◽  
Second Phase ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Second Phase Particles ◽  
Coarse Grains ◽  
Sintered Silicon

Silicon nitride was fabricated by adding Y2O3 and Nd2O3 as sintering additives, sintering for 8 h at 1900 °C, and heat treating for 4 h at 2200 °C to enhance grain growth. The microstructure was investigated by scanning electron microscopy, high-resolution electron microscopy, energy dispersive x-ray spectroscopy (EDS), and electron microdiffraction. This material had a duplex microstructure composed of many fine grains and a few coarse grains. In β–Si3N4 grains, second-phase particles with the composition of liquid phase, Y–Nd–Si–O or Y–Nd–Si–O–N, in the size of 10–30 nm were observed. EDS spectra and microdiffraction patterns revealed that those were amorphous or crystalline particles of Y–Nd–apatite, (Y,Nd)10Si6O24N2. These particles were presumably formed during cooling by the precipitation of Y–Nd–Si–O–N, which was trapped in the β–Si3N4 grains as solid solution or trapped liquid. The results suggest that attention should be paid to the trace amounts of trapped elements in β–Si3N4 grains in trying to improve the thermal conductivity of sintered silicon nitride.

Continuous and Discontinuous Recrystallization of 6013 Aluminum Alloy

2013 ◽  
Vol 753 ◽  
pp. 221-224 ◽  
Author(s):  
Krzysztof Sztwiertnia ◽  
Magdalena Bieda ◽  
Anna Korneva
Keyword(s):  
Aluminum Alloy ◽  
Grain Boundaries ◽  
Second Phase ◽  
Sheet Plane ◽  
Temperature Range ◽  
Orientation Mapping ◽  
Second Phase Particles ◽  
The Matrix ◽  
Continuous Recrystallization

In situ orientation mapping using TEM and calorimetric measurements were carried out to investigate the annealing behavior of cold-rolled 6013 aluminum alloy. The recrystallization of the material can be considered to be a number of processes that correspond to two separate stored energy release peaks. In the temperature range of the peak 1, the deformation zones around the large second-phase particles acted as sites for particle-stimulated nucleation. In the matrix, at the same time, some elongation of grains occurred. The elongated matrix grains appeared because of the reduction of the dislocation density and the annihilation of some low-angle grain boundaries between chains of subgrains lying in layers parallel to the sheet plane. The matrix processes in this temperatures range can be considered forms of continuous recrystallization. The matrix high-angle grain boundaries started to migrate at the temperature range of the peak 2. They moved mostly in the direction normal to the sheet plane. Heating of the sample for an appropriate time at those temperatures resulted in the complete discontinuous recrystallization of the material. The recrystallized microstructure was dominated now by elongated grains, which were a few times thicker than those obtained by annealing at the temperatures of the peak 1.

scholarly journals Dissolution of the second phase particles in the course of the equal channel angular pressing of diluted Cu‑Cr‑Zr alloy

2018 ◽  
Vol 8 (1) ◽  
pp. 110-114 ◽  
Author(s):  
I. A. Faizov ◽  
R. R. Mulyukov ◽  
D. A. Aksenov ◽  
S. N. Faizova ◽  
N. V. Zemlyakova ◽  
...  
Keyword(s):  
Equal Channel Angular Pressing ◽  
Second Phase ◽  
Angular Pressing ◽  
Second Phase Particles ◽  
Zr Alloy

Mismatch and misorientation at the precipitate/matrix interface in an Al-Zralloy

1983 ◽  
Vol 41 ◽  
pp. 242-243
Author(s):  
Angus Porter ◽  
Louise Makin ◽  
Brian Ralph
Keyword(s):  
High Strength ◽  
Second Phase ◽  
Exact Nature ◽  
Matrix Interface ◽  
Single Image ◽  
Second Phase Particles ◽  
The Matrix ◽  
Lattice Planes ◽  
Zr Alloy ◽  
Zr Alloys

Much of the hardening of high strength aluminium alloys containing zirconium results from the precipitation of the metastable γ' (Al3Zr) phase (Ll2 structure, cube/cube related to the matrix). There exists some controversy in the literature as to the magnitude of the matrix (γ)-γ' misfit in Al-Zr alloys; the values reported range from 1% down to rather less than half this figure. In the present paper, the use of moire fringe imaging to study mismatch and misorientation between the γ and γ' lattice in a binary Al-Zr alloy will be considered. The advantages of this technique for the study of small second-phase particles are three-fold. The information obtained is specific to a single particle; the exact nature of the particle/matrix interface is unimportant, as long as the two lattices exhibit nearly coincident diffraction maxima; and mismatch and misorientation of particular sets of lattice planes can be determined from a single image.

Effect of Zn, Mg, Cu, Zr on Microstructure and Properties of Laser Welding Aluminium Alloy

2016 ◽  
Vol 877 ◽  
pp. 593-600 ◽  
Author(s):  
Zhi Hao Zhao ◽  
Wen Qiang Liu ◽  
Kai Tao ◽  
Qi Chao Chen ◽  
Gao Song Wang
Keyword(s):  
Laser Welding ◽  
Aluminium Alloy ◽  
Extrusion Direction ◽  
Optical Microscope ◽  
Second Phase ◽  
Ingot Metallurgy ◽  
Extrusion Processing ◽  
Second Phase Particles ◽  
Metallurgical Structure ◽  
Scanning Electron

A series of Al-6.3Zn-2.3Mg-2.3Cu-0.15Zr alloys with different reduce of Zn, Mg, Cu and Zr were prepared by ingot-metallurgy processing. The metallurgical structure and mechanical properties were investigated by optical microscope, scanning electron microscopy and other equipment. The results indicated that the ingot’s microstructures of the four alloys contain the phrases of η (MgZn2) and θ (Al2Cu), which mostly distribute at the grain boundaries in a shape of continuous network. After extrusion processing, the grain of laser welding aluminium alloy was elongated along the extrusion direction, therefore forming fibrous structures, and meanwhile the second phase particles with different degrees of fragmentation were arranged along the extrusion direction since the microstructure of extruded bars was inherited by the as-cast structure. Zr could significantly inhibit recrystallization of alloy; the recrystallization of the alloy with lower Zr was more obvious. As the content of Zr reduced, the tensile strength of alloy decreased, but the electrical conductivity and hardness increased. When the content of Cu was lower, the hardness were decreased.

Deformation and Annealing Textures of Extruded and Cold Rolled Pure Ni Single Crystals of Cube Orientation

2007 ◽  
Vol 353-358 ◽  
pp. 707-710
Author(s):  
Kun Li ◽  
Andrew Godfrey ◽  
Wei Liu ◽  
Qing Liu
Keyword(s):  
Electron Microscope ◽  
Large Change ◽  
Normal Direction ◽  
Sample Thickness ◽  
Electron Backscattered Diffraction ◽  
Cube Orientation ◽  
Cumulative Change ◽  
Cold Rolled ◽  
Misorientation Angles ◽  
Scanning Electron

A pure Ni single crystal of Cube orientation (001)/[100] have been deformed by reversible cold rolling to a reduction of 98% following an initial extrusion treatment. The microstructure in the as-deformed samples and in partly recrystallized specimens have been characterized in the scanning electron microscope using electron backscattered diffraction (EBSD). Line scans along the normal direction across the sample thickness show some evidence for a macroscopic pattern of subdivision. The EBSD measurements show that the deformed sample is characterized by large jumps in orientation between alternating S and Br orientations, related by misorientation angles of 50°~60°. In part of the sample a background cumulative change in orientation is seen, though local large change in orientation are also still seen. In annealed samples it is found that the orientations of the new grains

Sign in / Sign up

Export Citation Format

Share Document