scholarly journals Influence of thermomechanical processing on the grain size, texture and mechanical properties of Mg-Al alloys

2012 ◽  
Vol 50 (01) ◽  
pp. 1-23
Author(s):  
B. SRINIVASARAO ◽  
J. A. DEL ◽  
O. A. RUANO ◽  
M. T. PÉREZ-PRADO
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Thermomechanical Processing ◽  
Al Alloys

Effect of Thermomechanical Processing on Grain Size, Texture and Mechanical Properties of Pure Magnesium

2020 ◽  
Vol 985 ◽  
pp. 97-108
Author(s):  
Mouhamadou Moustapha Sarr ◽  
Motohiro Yuasa ◽  
Hiroyuki Miyamoto
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Yield Stress ◽  
Thermomechanical Processing ◽  
Pure Magnesium ◽  
Grain Structure ◽  
Misorientation Distribution ◽  
Processed Material ◽  
Texture Characterization

This study aims to investigate the effect of processing routes (A and Bc) and temperature on microstructure, texture and mechanical properties of pure magnesium was studied in this research. An extruded pure magnesium (~99,9 %) was subjected to severe plastic deformation (SPD) by ECAP. Deformation was conducted at 523K and 473K and two different processing routes (A and Bc) were used to control the texture. The microstructure and texture characterization of the pressed materials were carried out. It was found that the microstructure displayed a bimodal grain structure after two passes and then became homogeneous after four passes following both routes A and Bc. The misorientation distribution was examined and the results revealed that the fraction of high angle grain boundaries (HAGB) was higher at temperature 473K. The texture was randomized following route Bc whereas it became strengthened in route A after four passes. According to the Hall-Petch (HP) relationship, the yield stress of polycrystalline metals increases with a decrease in grain size. In this study, a positive slope k was achieved in the strengthened texture while a negative one was obtained in the softened texture. The ductility of ECAP processed material was considerably improved (from 23% to 38%) without sacrificing the yield stress by route Bc at 423K.

Novel Grain Refiner for Hypo- and Hyper-Eutectic Al-Si Alloys

2011 ◽  
Vol 690 ◽  
pp. 49-52 ◽  
Author(s):  
Magdalena Nowak ◽  
Nadendla Hari Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Al Alloys ◽  
Grain Structure ◽  
Grain Refiner ◽  
Silicon Alloys ◽  
Fine Grain ◽  
Cooling Conditions ◽  
Wide Range ◽  
Master Alloys

A novel effective grain refiner for hypo and hyper-eutectic Aluminium-Silicon alloys has been developed. The composition of the grain refiner has been optimized to produce a fine grain structure and finer eutectic. Effectiveness of grain size under various cooling conditions has also been investigated to simulate various practical casting conditions. For comparative purposes, a wide range of Al alloys have been produced with the addition of commercially available Al-5Ti-B master alloys. The results show that the addition of novel grain refiner reduces the grain size significantly. As a result of fine grains, the porosity in the solidified alloys is remarkably lower. A notable improvement in mechanical properties has also been observed.

Effects of Mg Content on Electric and Mechanical Properties of Al–Zn–Cu Based Alloys

2021 ◽  
Vol 21 (3) ◽  
pp. 2015-2018
Author(s):  
Yong-Ho Kim ◽  
Hyo-Sang Yoo ◽  
Kyu-Seok Lee ◽  
Sung-Ho Lee ◽  
Hyeon-Taek Son
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Al Alloys ◽  
Lattice Constants ◽  
Cu Alloy ◽  
Average Grain Size ◽  
Mg Content

Microstructure and properties of Al–2 wt.%Zn–1 wt.%Cu–xMg (x = 0.1, 0.3, 0.5, 0.7 wt.%) alloy extrusion materials were investigated. The lattice constants for the (311) plane increased to 4.046858, 4.048483, 4.050114 and 4.051149 Å with the addition of 0.1, 0.3, 0.5, and 0.7 wt.% of elemental Mg. The average grain size of the as-extruded Al alloys was found to be 328.7, 297.7, 187.0 and 159.3 μm for the alloys with 0.1, 0.3, 0.5, and 0.7 wt.% Mg content, respectively. The changes in the electrical conductivity by the addition of elemental Mg in Al–2 wt.%Zn–1 wt.%Cu alloy was determined, and it was found that for the addition of 0.1, 0.3, 0.5, and 0.7 wt.% Mg, the conductivity decreased to 51.62, 49.74, 48.26 and 46.80 %IACS. The ultimate tensile strength of Al–2 wt.%Zn–1 wt.%Cu–0.7 wt.%Mg alloy extrusion was increased to 203.55 MPa. Thus, this study demonstrated the correlation between the electrical conductivity and strength for the Al–2 wt.%Zn–1 wt.%Cu–xMg alloys.

First-principles calculations for understanding the microstructures and mechanical properties of co-sputtered Al alloys

Nanoscale ◽  
2021 ◽  
Author(s):  
Mingyu Gong ◽  
Wenqian Wu ◽  
Dongyue Xie ◽  
Nicholas A Richter ◽  
Qiang Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
First Principles ◽  
Experimental Studies ◽  
Al Alloys ◽  
First Principles Calculations ◽  
Planar Defects ◽  
Microstructures And Mechanical Properties ◽  
Columnar Grain ◽  
The Stability

Recent experimental studies show that co-sputtering solutes with Al together can refine columnar grain size around few tens nanometers and promote formation and enhance the stability of planar defects such...

Effect of Thermomechanical Processing on Structure and Corrosion-Mechanical Properties of AISI 321 Steel

2010 ◽  
Vol 89-91 ◽  
pp. 769-772
Author(s):  
G.E. Kodzhaspirov ◽  
A.I. Rudskoy ◽  
V.V. Rybin
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Fine Structure ◽  
Dislocation Density ◽  
Mechanical Strength ◽  
Thermomechanical Processing ◽  
Test Procedure ◽  
Nacl Solution ◽  
Aisi 321 ◽  
Carbide Transformations

The effect of Thermomechanical Processing (TMP) on the fine structure (dislocation density and fragments evolution), recrystallization, carbide transformations and tendency toward intercrystalline corrosion (ICC) and corrosion-mechanical strength of AISI 321 type steels is described. It’s shown that the grain size and overall amount of carbide phase has almost no effect on ICC. With an increase in dislocation density a tendency is observed toward a reduction in corrosion rate, but increases with an increase in proportion of recrystallized material. This connection is explained by an increasing of the level of local microstresses, which may be arranged structurally in the form of partial disclinations and aggravate ICC. A new test procedure was developed for estimating the corrosion-mechanical strength of steel. It follows from the obtained data that the hot working with the following accelerate cooling under industrial conditions does not develop a tendency toward corrosion cracking in 3% agueous NaCl solution.

Effect of Severe Plastic Deformation on the Mechanical Behavior of Ti-6Al-4V

2003 ◽  
Author(s):  
Ibrahim Karaman ◽  
G. Guven Yapici
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Strain Hardening ◽  
Room Temperature ◽  
Equal Channel Angular Extrusion ◽  
Thermomechanical Processing ◽  
Processing Route ◽  
Plate Size ◽  
Different Temperatures ◽  
Tension And Compression

The present work focuses on the microstructural evolution and resulting room temperature mechanical properties of P/M Ti-6Al-4V severely deformed at different temperatures (550°C to 800°C) using Equal Channel Angular Extrusion (ECAE). The bulk materials are extruded through two channels of equal cross section intersecting an angle of 90 degree. Microstructure and mechanical properties of extruded billets are reported through electron microsopy observations and tension, compression and hardness experiments. Results are compared for different extrusion conditions including variations in temperature and processing route. Higher hardness values are obtained after ECAE compared to as-received values. These improvements are correlated with the grain refinement, phase refinement and texture produced during ECAE. The most favorable microstructure in terms of refined grains was two passes at 600°C. The ultimate goal is to develop ECAE thermomechanical-processing maps for the selection of processing schedules to obtain desired end microstructures and improved fatigue life in Ti-Al-V based materials. The investigations revealed that: 1. ECAE shear deformation leads to refinement in β plates and elimination of piror β boundaries. Decreasing extrusion temperature and increasing number of passes decreases α plate size and grain size. Refined α grain size leads to a significant increase in tensile and compressive flow stresses at room temperature. 2. The second extrusion pass at 800°C increased both the yield strength and ductility. This was attributed to the observed α plate refinement. 3. Cavitation at the interface between β strips and α plates at 550°C was thought to be the reason for low ductility and relatively low strain hardening at room temperature. 4. Texture has a pronounced effect on mechanical properties. Tension/compression asymmetry in flow strengths and strain hardening coefficients may be described by the activation of differing slip systems under tension and compression loading because of texture.

Surface Modification and its Influence on the Microstructure and Creep Resistance of Nickel Based Superalloy René 77 / Modyfikacja Powierzchniowa Oraz Jej Wpływ Na Mikrostrukture I Wytrzymałosc Na Pełzanie Odlewów Z Nadstopu Niklu Ren´E 77

2013 ◽  
Vol 58 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Zielinska ◽  
J. Sieniawski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Surface Modification ◽  
Turbine Blades ◽  
Processing Parameters ◽  
Grain Structure ◽  
Creep Tests ◽  
Cobalt Aluminate ◽  
Nickel Based Superalloy ◽  
Average Grain Size

Superalloy René 77 is very wide used for turbine blades, turbine disks of aircraft engines which work up to 1050°C. These elements are generally produced by the investment casting method. Turbine blades produced by conventional precision casting methods have coarse and inhomogeneous grain structure. Such a material often does not fulfil basic requirements, which concern mechanical properties for the stuff used in aeronautical engineering. The incorporation of controlled grain size improved mechanical properties. This control of grain size in the casting operation was accomplished by the control of processing parameters such as casting temperature, mould preheating temperature, and the use of grain nucleates in the face of the mould. For nickel and cobalt based superalloys, it was found that cobalt aluminate (CoAl2O4) has the best nucleating effect. The objective of this work was to determine the influence of the inoculant’s content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties at high temperature of nickel based superalloy René 77. For this purpose, the ceramic moulds were made with different concentration of cobalt aluminate in the primary slurry was from 0 to 10% mass. in zirconium flour. Stepped and cylindrical samples were casted for microstructure and mechanical examinations. The average grain size of the matrix ( phase), was determined on the stepped samples. The influence of surface modification on the grain size of up to section thickness was considered. The microstructure investigations with the use of light microscopy and scanning electron microscopy (SEM) enable to examine the influence of the surface modification on the morphology of ’ phase and carbides precipitations. Verification of the influence of CoAl2O4 on the mechanical properties of castings were investigated on the basis of results obtained form creep tests.

Structural features and strength behavior of TRIP/TWIP steels

2020 ◽  
pp. 5-18
Author(s):  
D. V. Prosvirnin ◽  
◽  
M. S. Larionov ◽  
S. V. Pivovarchik ◽  
A. G. Kolmakov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Thermomechanical Processing ◽  
Maximum Load ◽  
Structural Features ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Structural And Functional Properties ◽  
Twip Steels ◽  
The Creation

A review of the literature data on the structural features of TRIP / TWIP steels, their relationship with mechanical properties and the relationship of strength parameters under static and cyclic loading was carried out. It is shown that the level of mechanical properties of such steels is determined by the chemical composition and processing technology (thermal and thermomechanical processing, hot and cold pressure treatment), aimed at achieving a favorable phase composition. At the atomic level, the most important factor is stacking fault energy, the level of which will be decisive in the formation of austenite twins and / or the formation of strain martensite. By selecting the chemical composition, it is possible to set the stacking fault energy corresponding to the necessary mechanical characteristics. In the case of cyclic loads, an important role is played by the strain rate and the maximum load during testing. So at high loading rates and a load approaching the yield strength under tension, the intensity of the twinning processes and the formation of martensite increases. It is shown that one of the relevant ways to further increase of the structural and functional properties of TRIP and TWIP steels is the creation of composite materials on their basis. At present, surface modification and coating, especially by ion-vacuum methods, can be considered the most promising direction for the creation of such composites.

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