scholarly journals Counterions, smectite, and palygorskite increase microstructural stability of saline-sodic soils

2022 ◽  
Vol 216 ◽  
pp. 105258
Author(s):  
F. Javaheri ◽  
I. Esfandiarpour-Boroujeni ◽  
M.H. Farpoor ◽  
D. Holthusen ◽  
R.D. Stewart
Keyword(s):  
Microstructural Stability ◽  
Sodic Soils

scholarly journals Counterions, smectite, and palygorskite increase microstructural stability of saline-sodic soils

2021 ◽  
Vol 211 ◽  
pp. 104994
Author(s):  
F. Javaheri ◽  
I. Esfandiarpour-Boroujeni ◽  
M.H. Farpoor ◽  
Dörthe Holthusen ◽  
R.D. Stewart
Keyword(s):  
Microstructural Stability ◽  
Sodic Soils

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

High-Temperature Instability of A Cr2Nb-Nb(Cr) Microlaminate Composite

1996 ◽  
Vol 54 ◽  
pp. 374-375
Author(s):  
M. Larsen ◽  
R.G. Rowe ◽  
D.W. Skelly
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Aircraft Engine ◽  
Lattice Parameter ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Cross Sectional ◽  
Bcc Structure

Microlaminate composites consisting of alternating layers of a high temperature intermetallic compound for elevated temperature strength and a ductile refractory metal for toughening may have uses in aircraft engine turbines. Microstructural stability at elevated temperatures is a crucial requirement for these composites. A microlaminate composite consisting of alternating layers of Cr2Nb and Nb(Cr) was produced by vapor phase deposition. The stability of the layers at elevated temperatures was investigated by cross-sectional TEM.The as-deposited composite consists of layers of a Nb(Cr) solid solution with a composition in atomic percent of 91% Nb and 9% Cr. It has a bcc structure with highly elongated grains. Alternating with this Nb(Cr) layer is the Cr2Nb layer. However, this layer has deposited as a fine grain Cr(Nb) solid solution with a metastable bcc structure and a lattice parameter about half way between that of pure Nb and pure Cr. The atomic composition of this layer is 60% Cr and 40% Nb. The interface between the layers in the as-deposited condition appears very flat (figure 1). After a two hour, 1200 °C heat treatment, the metastable Cr(Nb) layer transforms to the Cr2Nb phase with the C15 cubic structure. Grain coarsening occurs in the Nb(Cr) layer and the interface between the layers roughen. The roughening of the interface is a prelude to an instability of the interface at higher heat treatment temperatures with perturbations of the Cr2Nb grains penetrating into the Nb(Cr) layer.

EFFECT OF FLY ASH ON CROP YIELD AND PHYSICO-CHEMICAL, MICROBIAL AND ENZYME ACTIVITIES OF SODIC SOILS

2016 ◽  
Vol 15 (11) ◽  
pp. 2433-2440 ◽  
Author(s):  
Kripal Singh ◽  
Vimal Chandra Pandey ◽  
Bajrang Singh ◽  
Dharani D. Patra ◽  
Rana P. Singh
Keyword(s):  
Fly Ash ◽  
Crop Yield ◽  
Enzyme Activities ◽  
Sodic Soils ◽  
Physico Chemical

scholarly journals Texture Selection Mechanisms during Recrystallization and Grain Growth of a Magnesium-Erbium-Zinc Alloy

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 171
Author(s):  
Fatim-Zahra Mouhib ◽  
Fengyang Sheng ◽  
Ramandeep Mandia ◽  
Risheng Pei ◽  
Sandra Korte-Kerzel ◽  
...  
Keyword(s):  
Grain Growth ◽  
Ternary Alloy ◽  
Solute Drag ◽  
Tensile Tests ◽  
Electron Back Scatter Diffraction ◽  
Zinc Alloy ◽  
Uniaxial Tensile ◽  
Microstructural Stability ◽  
Solid Solution Strengthening ◽  
Zener Drag

Binary and ternary Mg-1%Er/Mg-1%Er-1%Zn alloys were rolled and subsequently subjected to various heat treatments to study texture selection during recrystallization and following grain growth. The results revealed favorable texture alterations in both alloys and the formation of a unique ±40° transvers direction (TD) recrystallization texture in the ternary alloy. While the binary alloy underwent a continuous alteration of its texture and grain size throughout recrystallization and grain growth, the ternary alloy showed a rapid rolling (RD) to transvers direction (TD) texture transition occurring during early stages of recrystallization. Targeted electron back scatter diffraction (EBSD) analysis of the recrystallized fraction unraveled a selective growth behavior of recrystallization nuclei with TD tilted orientations that is likely attributed to solute drag effect on the mobility of specific grain boundaries. Mg-1%Er-1%Zn additionally exhibited a stunning microstructural stability during grain growth annealing. This was attributed to a fine dispersion of dense nanosized particles in the matrix that impeded grain growth by Zener drag. The mechanical properties of both alloys were determined by uniaxial tensile tests combined with EBSD assisted slip trace analysis at 5% tensile strain to investigate non-basal slip behavior. Owing to synergic alloying effects on solid solution strengthening and slip activation, as well as precipitation hardening, the ternary Mg-1%Er-1%Zn alloy demonstrated a remarkable enhancement in the yield strength, strain hardening capability, and failure ductility, compared with the Mg-1%Er alloy.

Growth, Oil Yield, and Ion Partitioning in Basil Grown on Sodic Soils

2008 ◽  
Vol 39 (5-6) ◽  
pp. 833-844 ◽  
Author(s):  
A. K. Nayak ◽  
R. K. Gautam ◽  
D. K. Sharma ◽  
V. K. Mishra ◽  
C. S. Singh ◽  
...  
Keyword(s):  
Oil Yield ◽  
Sodic Soils ◽  
Ion Partitioning

Microstructural stability of rapidly-solidified CuB alloys

1988 ◽  
Vol 98 ◽  
pp. 161-164 ◽  
Author(s):  
E. Batawi ◽  
M.A. Morris ◽  
D.G. Morris
Keyword(s):  
Microstructural Stability ◽  
Rapidly Solidified

Microstructural stability of γ′ strengthened Co–Cr–Ti alloys

Metal Science ◽  
1983 ◽  
Vol 17 (4) ◽  
pp. 159-166 ◽  
Author(s):  
N.-G. Ingesten ◽  
R. Warren ◽  
M. Dahlén
Keyword(s):  
Microstructural Stability ◽  
Ti Alloys

scholarly journals Achieving high strength and ductility in ODS-W alloy by employing oxide@W core-shell nanopowder as precursor

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhi Dong ◽  
Zongqing Ma ◽  
Liming Yu ◽  
Yongchang Liu
Keyword(s):  
High Temperature ◽  
Metal Matrix ◽  
High Performance ◽  
High Energy ◽  
Core Shell ◽  
Microstructural Stability ◽  
Oxide Particles ◽  
Ods Alloy ◽  
Prepared Alloy ◽  
Strength And Ductility

AbstractWith excellent creep resistance, good high-temperature microstructural stability and good irradiation resistance, oxide dispersion strengthened (ODS) alloys are a class of important alloys that are promising for high-temperature applications. However, plagued by a nerve-wracking fact that the oxide particles tend to aggregate at grain boundary of metal matrix, their improvement effect on the mechanical properties of metal matrix tends to be limited. In this work, we employ a unique in-house synthesized oxide@W core-shell nanopowder as precursor to prepare W-based ODS alloy. After low-temperature sintering and high-energy-rate forging, high-density oxide nanoparticles are dispersed homogeneously within W grains in the prepared alloy, accompanying with the intergranular oxide particles completely disappearing. As a result, our prepared alloy achieves a great enhancement of strength and ductility at room temperature. Our strategy using core-shell powder as precursor to prepare high-performance ODS alloy has potential to be applied to other dispersion-strengthened alloy systems.

Sign in / Sign up

Export Citation Format

Share Document