Evolution of Hot Rolling and Phase Transformation Textures in an α″ (Orthorhombic) Phase in Ti-Nb Alloys

2011 ◽  
Vol 702-703 ◽  
pp. 872-875
Author(s):  
S. Banumathy ◽  
Rajiv Kumar Mandal ◽  
A.K. Singh
Keyword(s):  
Hot Rolling ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Orthorhombic Phase ◽  
Moderate Intensity ◽  
Large Volume Fraction ◽  
Β Phase ◽  
Rolled Condition ◽  
Textural Changes ◽  
Hot Rolled

This work describes the development of texture during hot rolling of two alloys namely, Ti-12Nb and Ti-16Nb. The alloys have been unidirectionally hot rolled to 80 % reductions at 800°C and air cooled. Both the alloys show the presence of a² (orthorhombic) and small volume fraction of b (bcc) phases in hot rolled condition. The alloy Ti-12Nb exhibit moderate intensity texture while the alloy Ti-16Nb displays quite strong texture. The high overall intensity of texture in alloy Ti-16Nb in 80 % HR specimen can be attributed to the presence of large volume fraction of b phase in comparison to that of the alloy Ti-12Nb. This has been extended to study the textural changes after b solution treatment. This heat treatment consists of two types of phase transformations that are a² ® b ® a² and a² ® b ® a after water quenching and furnace cooling from β phase field.

scholarly journals Effect of Thermomechanical Treatments on the Phases, Microstructure, Microhardness and Young’s Modulus of Ti-25Ta-Zr Alloys

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3210 ◽  
Author(s):  
Pedro Akira Bazaglia Kuroda ◽  
Fernanda de Freitas Quadros ◽  
Raul Oliveira de Araújo ◽  
Conrado Ramos Moreira Afonso ◽  
Carlos Roberto Grandini
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Hot Rolling ◽  
Young's Modulus ◽  
Solution Treatment ◽  
Alloy System ◽  
Slow Cooling ◽  
Β Phase ◽  
Transmission Electron ◽  
Hot Rolled

Titanium and its alloys currently are used as implants, possessing excellent mechanical properties (more suited than stainless steel and Co-Cr alloys), good corrosion resistance and good biocompatibility. The titanium alloy used for most biomedical applications is Ti-6Al-4V, however, studies showed that vanadium and aluminum cause allergic reactions in human tissues and neurological disorders. New titanium alloys without the presence of these elements are being studied. The objective of this study was to analyze the influence of thermomechanical treatments, such as hot-rolling, annealing and solution treatment in the structure, microstructure and mechanical properties of the Ti-25Ta-Zr ternary alloy system. The structural and microstructural analyses were performed using X-ray diffraction, as well as optical, scanning and transmission electron microscopy. The mechanical properties were analyzed using microhardness and Young’s modulus measurements. The results showed that the structure of the materials and the mechanical properties are influenced by the different thermal treatments: rapid cooling treatments (hot-rolling and solubilization) induced the formation of α” and β phases, while the treatments with slow cooling (annealing) induced the formation of martensite phases. Alloys in the hot-rolled and solubilized conditions have better mechanical properties results, such as low elastic modulus, due to retention of the β phase in these alloys.

scholarly journals Strain Hardening and Stretch Formability Behavior of Triple Phase (TP) Steel Strips

2021 ◽  
Vol 27 (3) ◽  
pp. 152-156
Author(s):  
Maha ElMeligy ◽  
Taher El-Bitar
Keyword(s):  
Strain Hardening ◽  
Volume Fraction ◽  
Salt Bath ◽  
Holding Time ◽  
Forming Limit ◽  
Stretch Forming ◽  
Steel Strips ◽  
Stretch Formability ◽  
Rolled Condition ◽  
Hot Rolled

The current work explores the strain hardening and stretches formability behaviour of the developed Triple Phase (TP) steel. Double quenched TP steel strips posse three distinguished stages of strain hardening on tensile forming. 1st stage represents the highest n-value reflecting resistance to homogeneous deformation, where steel can be safely stretched. 2nd and 3rd stage reveals lower n-values, where localized thinning exist. On Erichsen testing, the relationship between punch forming force and punch stroke exhibits two forming regions. The 1st region is delineated by a straight line showing an ultra-high strain-hardening rate, which represents a reversible elastic stretch forming.  The 2nd forming region continues to a higher Erichsen punch stroke than that of the 1st region and presents the permanent plastic stretch forming behaviour.  It is found that bainite and martensite clusters created, by double quenching, in TP-steel exaggerated the elastic stretch forming limit 10 times higher than the as-hot rolled condition. 7 min. holding time of strips in the salt bath is considered the most effective for the creation of a useful volume fraction of the bainite phase. However, 21 min. holding time in salt bath grows martensite laths through the bainite aggregates, affecting negatively on stretch formability.

HREM of Rapidly Solidified Al-Li-Zr Based Alloys

1990 ◽  
Vol 48 (1) ◽  
pp. 54-55
Author(s):  
V. Radmilovic ◽  
G. Thomas ◽  
R. Kilaas ◽  
N. J. Kim
Keyword(s):  
Volume Fraction ◽  
Solution Treatment ◽  
Aging Treatment ◽  
High Resolution Electron Microscopy ◽  
Image Simulation ◽  
Large Volume Fraction ◽  
Heat Treated ◽  
Resolution Electron ◽  
Rapidly Solidified

During aging of Al-Li-Zr based alloys δ'(Al3Li) precipitates heterogeneously around β'(Al3Zr), forming so-called composite precipitate[l-4], that has important effects on the mechanical behavior of these alloys. As has been observed in several investigations, the addition of small amount of Zr results in a fairly large volume fraction of β' in the microstructure, and this suggests that there may be a partitioning of Li in the β'. In the present investigation, high resolution electron microscopy (HREM) and image simulation have been used to perform detailed characterization of the chemistry and structure of β' precipitate.The alloy Al-3Li-1Cu-0.5Mg-0.5Zr (wt.%) has been heat treated as follows: a) solution treatment at 550°C for 2 hours and water quenching, b) aging treatment at 150°C for 4 hours or at 200°C for 8 hours and c) 10% cold working followed by aging at 175°C for 64 hours. HREM images were taken on a JEOL ARM electron microscope operating at 400 and 800kV. Simulated HREM images of the composite δ'/β' precipitate were calculated using CEMPAS multislice program described by Kilaas[5].

Microstructural evolution and mechanical properties response of the ZT40 alloy with hot rolling

2015 ◽  
Vol 12 (5) ◽  
pp. 431-436 ◽  
Author(s):  
Xu Qiao ◽  
Shunxing Liang ◽  
Lixia Yin ◽  
Dandan Li
Keyword(s):  
Mechanical Properties ◽  
Microstructural Evolution ◽  
Hot Rolling ◽  
Volume Fraction ◽  
Zirconium Alloys ◽  
Preferred Orientation ◽  
Rolling Reduction ◽  
Practical Applications ◽  
Rolled Specimen ◽  
Hot Rolled

The Zr-40Ti-4.5Al-4.2V (ZT40) alloy is one of new developed Zirconium alloys with high mechanical properties and great potential for application. The investigation about effects of plastic deformation on microstructure and mechanical properties can promote practical applications of the new high performance ZrTi based alloys. The microstructural evolution and mechanical properties of the ZT40 alloy suffered hot rolling with thickness reduction from 30% to 60% at 775 °C are investigated in this work. Results show that the phase constitution changes from (α + β) to (β + fcc) while the original specimen underwent hot rolling and subsequent water quenching. The β phase in hot rolled specimen adopts preferred orientation form (200) and (211) planes to only (200) plane while the rolling reduction increases from 30% to 60%. Furthermore, no obvious preferred orientation can be detected in specimen with reductions of 60%. Micrographs analysis shows that the dynamic recrystallization occurs in hot rolled specimens. Volume fraction of the DRX grains is approximately 8% in 30% reduction specimen and increases with the increasing of rolling reduction. Nearly full recrystallization is observed in the specimen with reductions of 60%. Hardness test shows that the HV of hot rolled specimen decreases from 384 HV to 329 HV as the increasing of reduction from 30% to 60%. The mechanisms of microstructural evolution and variation of hardness are also discussed. The finding should contribute to understand microstructural evolution, to adjust mechanical properties and to promote practical applications of Zirconium alloys.

Investigation on Microstructures of Heat Treated Mg-Zr and Mg-Mn Alloys

2005 ◽  
Vol 488-489 ◽  
pp. 189-192 ◽  
Author(s):  
Jian Ping Li ◽  
Gordon W. Lorimer ◽  
Joseph D. Robson ◽  
B. Davis
Keyword(s):  
Large Volume ◽  
Fine Particles ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Weight Percent ◽  
Large Volume Fraction ◽  
Heat Treated ◽  
Different Temperatures ◽  
Mn Content ◽  
Zr Alloys

The microstructure of three dilute Mg-Mn and two dilute Mg-Zr alloys which had been heat treated at different temperatures and times were studied using optical microscopy and various electron optical techniques, including FEGSEM and TEM. It was found that the Mg-Zr alloys homogenized at 500°C and annealed at 350°C contained a fine dispersion of Zr-containing particles at grain boundaries and within grains. In contrast, annealing Mg-Zr alloys at 300°C for up to 3 h led to little modification of the as-cast structures. When the Mn content was less than 0.9 weight percent, homogenization of the Mg-Mn alloys at 550 to 600°C resulted in the dissolution of small rod-like and needle-shape particles, which then grown up as fine particles when aged at 300°C. Mg- 0.6Mn and Mg-0.9Mn alloys annealed at 300 to 400°C without solution treatment contained a large volume fraction of nano-sized precipitates.

The Effect of Hot-Rolled Coiling Time on the Texture of a New Cold-Rolled Non-Oriented Electric Steel

2011 ◽  
Vol 194-196 ◽  
pp. 375-378
Author(s):  
Guan Qiao Hu ◽  
Yan Ping Zeng ◽  
Hai Lin Chen
Keyword(s):  
Hot Rolling ◽  
Electrical Steel ◽  
Volume Fraction ◽  
Test Results ◽  
Electric Steel ◽  
Coiling Temperature ◽  
Goss Texture ◽  
Cold Rolled ◽  
Hot Rolled

The effects of hot-rolling coiling time on texture of a new cold-rolled non-oriented electrical steel containing copper were investigated. The test results showed that the final product texture consists of γ-fibr textures, α-fibre textures and Goss. With adding coiling time ,the density of {111}<110> and {112}<110> decreased,the inverse Goss texture {001}<110> increased. The volume fraction of {100} raised with coiling time. As a certain coiling temperature, it can improve the intensity of textures {100},{110}at proper coiling time.

Precipitation Behavior and Microstructure Evolution of Mg-Zn-Zr-Er Alloy Processed by Secondary Deformation and Heat Treatment

2013 ◽  
Vol 747-748 ◽  
pp. 377-382
Author(s):  
Bao Xiang Zhang ◽  
Jing Zhang
Keyword(s):  
Microstructure Evolution ◽  
Hot Rolling ◽  
Volume Fraction ◽  
Rolling Direction ◽  
Hardness Test ◽  
Secondary Phase ◽  
Rolling Process ◽  
Second Phase ◽  
Precipitation Behavior ◽  
Hot Rolled

Preheated at 673K for 3h and 6h respectively, as-extruded Mg-9Zn-0.6Zr-2Er (wt.%) slabs with starting thickness of 8mm were hot-rolled at 673K to 2mm. The hot-rolled alloys were then solution treated at 673K for1.5h and aged at 473K for 10h. Microstructure evolution and second phase precipitation behavior during hot rolling and subsequent heat treatments were examined by optical microscopy (OM), scan electron microscopy (SEM) and micro hardness test. Mg-9Zn-0.6Zr-2Er alloy were fully recrystallized with fine equiaxed grains after preheating for 3 hours, prolonging heating time leads to a higher degree of dissolution of secondary phase into Mg matrix but a coarsening of the microstructure. During hot rolling process, the volume fraction of the DRX grains increased gradually with increasing reduction ratio, shearing bands became visble in the final pass. Thermal stable Mg-Zn-Er intermetallic compounds distributed along rolling direction at the first rolling passes and became more homogenous in the final pass. More nanosized MgZn2 precipitated during hot rolling in the alloy preheated for 6h than that for 3h, leading to an enhanced precipitation hardening effect in the former.

Anisotropy Decrease in Sheets of 1424 Al-Mg-Li Alloy

2006 ◽  
Vol 519-521 ◽  
pp. 371-376 ◽  
Author(s):  
L.B. Khokhlatova ◽  
N.I. Kolobnev ◽  
I.N. Fridlyander ◽  
A.A. Alekseev ◽  
E.A. Lukina ◽  
...  
Keyword(s):  
Tensile Property ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Deformation Degree ◽  
Slow Cooling ◽  
Technological Plasticity ◽  
Fine Grained ◽  
Preliminary Annealing ◽  
Property Anisotropy ◽  
Hot Rolled

The fine-fibrous nonrecrystallized structure determines substantial tensile property anisotropy of hot rolled 1424 alloy sheets. In the present work the possibility of producing a fully recrystallized structure in cold rolled sheets was investigated. To improve a technological plasticity a cold rolling was performed after preliminary annealing of hot rolled sheets. The technological plasticity was studied by means of determination a critical deformation degree at plane strain compression at room temperature. The phase composition of hot rolled and annealed sheets was investigated using TEM and X-ray analysis. The uniform fine-grained and fully recrystallized structure in sheets was obtained after rolling with preliminary annealing at 350-380°C and final solid solution treatment. After the indicated above annealing the maximum volume fraction of the equilibrium S1-phase precipitates was observed in the alloy. After cooling in air from the annealing temperature it was found a very small quantity of δ′-phase and after slow cooling with the furnace this phase was practically absent. The fully recrystallized structure in sheets provides a substantial decrease of the tensile property anisotropy in three d irections.

scholarly journals Fabrication, Structure, and Mechanical and Ultrasonic Properties of Medical Ti6Al4V Alloys Part II: Relationship between Microstructure and Mechanical Properties and Ultrasonic Properties of Ultrasonic Scalpel

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 284
Author(s):  
Zheyu He ◽  
Hao He ◽  
Jia Lou ◽  
Yimin Li ◽  
Dongyang Li ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Sample Length ◽  
Average Amplitude ◽  
Ultrasonic Scalpel ◽  
Ultrasonic Properties ◽  
Β Phase ◽  
Ultrasonic Resonance

In this study, the ultrasonic resonance parameters of Ti6Al4V alloys under different heat treatments are measured by an impedance analyzer. The amplitude of the specimens is measured experimentally by means of optical microscope and image analysis software. These results show that the ultrasonic properties of Ti6Al4V alloys are closely related to β phase content and elastic modulus of the alloys. The highest volume fraction of the β phase appears in the specimen treated by solid solution treatment at 960 °C is 40.2%. These alloys present the lowest average elastic modulus (~99.69 GPa) and the minimum resonant frequency (55.06 kHz) and the highest average amplitude (21.48 µm) when the testing sample length is 41.25 mm. These findings can be used to guide the design of medical Ti6Al4V alloys for ultrasonic scalpels.

Microstructure and Texture Evolution during Hot Rolling of Mg-9Li-7Al-1Sn Alloy for Aerospace Application

2011 ◽  
Vol 702-703 ◽  
pp. 85-88
Author(s):  
Vinod Kumar ◽  
R. Balasubramaniam ◽  
Rajiv Shekhar ◽  
Kantesh Balani
Keyword(s):  
Hot Rolling ◽  
Texture Evolution ◽  
Rolling Process ◽  
Grain Structure ◽  
Aerospace Application ◽  
Β Phase ◽  
Hot Rolling Process ◽  
Α Phase ◽  
Hot Rolled ◽  
Increased Activity

In the present work, Mg - 9wt. % Li - 7% wt. Al – 1 wt. % Sn (LAT971) alloy was cast and hot rolled at ~573K. Phase analysis of LAT971 revealed the presence of dual phase structure namely Mg-rich α- and Li-rich β-phase. After hot rolling, it was observed that dynamic recrystallization led to refinement of the α-phase grain structure. Significant crystallographic texture evolution, characterized by electron backscatterd diffraction, revealed increased activity of the non-basal (101 ̅0) slip plane after conventional hot rolling process.

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