Flow Softening, Twinning and Dynamic Evolution of Second Phase Particles During Shear-Punch Deformation of a Rolled Mg-Y-Nd-Zr Alloy

2021 ◽  
Author(s):  
Mahmood Fatemi ◽  
Y. Moradipour ◽  
R. Chulist ◽  
Henryk Paul
Keyword(s):  
Flow Softening ◽  
Dynamic Evolution ◽  
Second Phase ◽  
Second Phase Particles ◽  
Shear Punch ◽  
Zr Alloy

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.

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.

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.

Effects of Trace ZrC on the Microstructure and Properties of Molybdenum Alloy

2013 ◽  
Vol 785-786 ◽  
pp. 76-80
Author(s):  
Hui Chao Cheng ◽  
Jing Lian Fan ◽  
Zhao Qian ◽  
Jia Min Tian
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Room Temperature ◽  
Tensile Fracture ◽  
Second Phase ◽  
Powder Metallurgy Method ◽  
Microstructure And Properties ◽  
Dimple Fracture ◽  
Second Phase Particles ◽  
Zr Alloy

The present study describes the effect of trace ZrC additive on the microstructure and properties of Mo-Ti-Zr alloy fabricated by powder metallurgy method. The results indicate that, ZrC addition effectively enhanced the tensile strength of the alloy both at room-temperature and high-temperature, the alloy with 0.4wt% ZrC has the highest tensile strength, which is 611MPa and 513MPa at 25°C and 800°C, respectively. The tensile fracture mainly consists of intergranular rupture at room temperature, while dimple fracture occurred at high temperature, which indicating higher elongation. Through observation from the micrograph and EDS analysis, ZrxOyCz second-phase particles were observed,which is derived from part of ZrC particles reacted with the oxygen and can suppress the oxygen segregation on grain boundary.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

Analytical Electron Microscopy Study of Second-Phase Particles in 7075 and 7475 Aluminum Alloys

1985 ◽  
Vol 43 ◽  
pp. 348-349
Author(s):  
M. Raghavan ◽  
J. Y. Koo ◽  
J. W. Steeds ◽  
B. K. Park
Keyword(s):  
Aluminum Alloys ◽  
Silicon Oxide ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Partial Substitution ◽  
Second Phase ◽  
X Ray ◽  
Second Phase Particles ◽  
Almost All

X-ray microanalysis and Convergent Beam Electron Diffraction (CBD) studies were conducted to characterize the second phase particles in two commercial aluminum alloys -- 7075 and 7475. The second phase particles studied were large (approximately 2-5μm) constituent phases and relatively fine ( ∼ 0.05-1μn) dispersoid particles, Figures 1A and B. Based on the crystal structure and chemical composition analyses, the constituent phases found in these alloys were identified to be Al7Cu2Fe, (Al,Cu)6(Fe,Cu), α-Al12Fe3Si, Mg2Si, amorphous silicon oxide and the modified 6Fe compounds, in decreasing order of abundance. The results of quantitative X-ray microanalysis of all the constituent phases are listed in Table I. The data show that, in almost all the phases, partial substitution of alloying elements occurred resulting in small deviations from the published stoichiometric compositions of the binary and ternary compounds.

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