The Role of Martensitic Transformation in Thermomechanical Development of Microstructure and Plasticity of Two-Phase Ti-6Al-4V Titanium Alloy

2016 ◽  
Vol 687 ◽  
pp. 3-10 ◽  
Author(s):  
Maciej Motyka ◽  
Jan Sieniawski ◽  
Waldemar Ziaja
Keyword(s):  
Plastic Deformation ◽  
Titanium Alloy ◽  
Martensitic Transformation ◽  
Titanium Alloys ◽  
Thermomechanical Processing ◽  
Solution Treatment ◽  
Phase Morphology ◽  
Two Phase ◽  
Α Phase ◽  
Hot Plasticity

Phase constituent morphology in microstructure of two-phase α+β titanium alloys is determined by conditions of thermomechanical processing consisting of sequential heat treatment and plastic deformation operations. Results of previous research indicate that particularly solution treatment preceding plastic deformation significantly changes α-phase morphology and determines hot plasticity of titanium alloys. In the paper thermomechanical processing composed of β solution treatment and following hot forging of Ti-6Al-4V titanium alloy was analysed. Development of martensite plates during heating up and hot deformation was evaluated. Microscopic examinations revealed that elongated and deformed α-phase grains were fragmented and transformed into globular ones. Significant influence of martensitic transformation on elongation coefficient of α-phase grains after plastic deformation was confirmed. Based on results of elevated temperature tensile tests it was established that α-phase morphology in examined two-phase α+β titanium alloy, developed in the thermomechanical processing, can enhance their hot plasticity – especially in the range of low strain rates.

The Effect of α-Phase Grains Morphology in Initial Microstructure on Superplasticity of Two-Phase Titanium Alloys

2016 ◽  
Vol 838-839 ◽  
pp. 143-149 ◽  
Author(s):  
Maciej Motyka ◽  
Jan Sieniawski
Keyword(s):  
Plastic Deformation ◽  
Titanium Alloys ◽  
Superplastic Deformation ◽  
Thermomechanical Processing ◽  
Ti6al4v Alloy ◽  
Two Phase ◽  
Fine Grained ◽  
Β Phase ◽  
Α Phase ◽  
Heating Up

It is generally accepted that fine-grained and equiaxed microstructure enables superplastic deformation of two-phase titanium alloys. Appropriate microstructure is usually developed in the thermomechanical processing with careful selection of the parameters of plastic deformation and heat treatment. Based on results of own research in this area increased superplasticity was found in Ti6Al4V alloy having microstructure containing highly deformed and elongated α-grains – considerably different from equiaxed ones. It was found that during heating up and first stage of superplastic deformation fragmentation of elongated α-phase grains occurred, followed by formation and growth of globular grains of that phase. Particular role of quenching of the Ti6Al4V alloy from the stable β-phase temperature range in thermomechanical processing was identified. It leads to increase of elongation coefficient of α-phase grains after plastic deformation but also restrains nucleation of the precipitates of secondary α-phase in further stages of thermomechanical processing. It was established that developed phase morphology of the alloy determined its hot plasticity – especially in the range of low strain rates typical for superplastic deformation.

scholarly journals The effect of plastic deformation on martensite decomposition process in Ti-6Al-4V alloy

2020 ◽  
Vol 321 ◽  
pp. 12034
Author(s):  
Maciej Motyka ◽  
Waldemar Ziaja ◽  
Anna Baran-Sadleja ◽  
Karol Slemp
Keyword(s):  
Plastic Deformation ◽  
Titanium Alloys ◽  
Scientific Literature ◽  
Thermal Analyses ◽  
Compressive Load ◽  
Two Phase ◽  
Temperature Range ◽  
Α Phase ◽  
Heat Treated ◽  
Kinetics Of

Microstructure and mechanical properties of heat treated martensitic two-phase α+β titanium alloys are in major perspective determined by results of martensite decomposition during tempering. The process of martensitic α’(α”) phase decomposition in titanium alloys, although utilized in industry for years, has not been sufficiently characterized in the scientific literature. Especially aspects of plastically deformed martensite decomposition is poorly described. Preliminary research results of water quenched Ti-6Al-4V alloy, subsequently cold deformed in compression and tempered at the temperature range of 600-900ºC for 1 and 2 h indicated that α’(α”) martensite undergoes strain hardening and deformed martensite laths exhibit tendency towards fragmentation and spheroidization during tempering at 900ºC. In the present paper, also α’(α”) martensite decomposition under compressive load applied at the temperature range of 600-900ºC is considered too. Based on light and scanning electron microscopy observations, thermal analyses and XRD measurements, the effect of plastic deformation on kinetics of martensite decomposition and morphology of α phase formed in the process is analysed.

Effect of Heat Treatment on the Microstructure Evolution of Ti-6Al-3Sn-3Zr-3Mo-3Nb-1W-0.2Si Titanium Alloy

2016 ◽  
Vol 879 ◽  
pp. 1828-1833 ◽  
Author(s):  
Xiao Yun Song ◽  
Wen Jing Zhang ◽  
Teng Ma ◽  
Wen Jun Ye ◽  
Song Xiao Hui
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
Microstructure Evolution ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
Water Quenching ◽  
Air Cooling ◽  
Two Phase ◽  
Β Phase ◽  
Α Phase

Ti-6Al-3Sn-3Zr-3Mo-3Nb-1W-0.2Si (BTi-6431S) alloy is a novel two-phase high temperature titanium alloy for short-term using in aerospace industry up to 700°C. The effects of heat treatment on the microstructure evolution of BTi-6431S alloy bar were investigated through optical microscopy (OM), X-ray diffraction (XRD), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). The results show that solution treatment in β region at 1010°C followed by water quenching results in the formation of orthorhombic martensite α′′ phase, while air cooling leads to the formation of hexagonal martensite α′ phase. When solution-treated in α+β phase field at temperatures from 900°C to 980°C following by water quenching, the content of primary α phase decreases with the increase of heat treatment temperature. For the alloy subjected to identical heat treatment, the content of Al in α phase is much higher than that in β phase, while the contents of Nb, Mo and W elements in α phase are much less than those in β phase.

scholarly journals Microstructural Characterization Of Quenched And Plastically Deformed Two-Phase α+β Titanium Alloys

2015 ◽  
Vol 60 (3) ◽  
pp. 2033-2038 ◽  
Author(s):  
M. Motyka ◽  
J. Sieniawski ◽  
W. Ziaja ◽  
G. Mrówka-Nowotnik
Keyword(s):  
Heat Treatment ◽  
Plastic Deformation ◽  
Titanium Alloys ◽  
Thermomechanical Processing ◽  
Microstructural Characterization ◽  
Two Phase ◽  
Deformation Degree ◽  
Plastic Deformation Process ◽  
Deformation Processes

Abstract Development of microstructure in two-phase α+β titanium alloys is realized by thermomechanical processing – sequence of heat treatment and plastic working operations. Analysis of achieved results indicates that hot plastic deformation – depending on deformation degree – causes significant elongation of α phase grains. Following heat treatment and plastic deformation processes lead to their fragmentation and spheroidization. Characterization of microstructure morphology changes during thermomechanical processing of quenched Ti-6Al-4V and Ti-6Al-2Mo-2Cr alloys is presented in the paper. The effect of martensitic phase α’(α”) on microstructure development in plastic deformation process was confirmed.

Modeling the anisotropy of hot plastic deformation of two-phase titanium alloys with a colony microstructure

2018 ◽  
Vol 104 ◽  
pp. 173-195 ◽  
Author(s):  
X.G. Fan ◽  
X.Q. Jiang ◽  
X. Zeng ◽  
Y.G. Shi ◽  
P.F. Gao ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Titanium Alloys ◽  
Two Phase ◽  
Hot Plastic Deformation

Morphology transformation of primary strip α phase in hot working of two-phase titanium alloy

2017 ◽  
Vol 27 (6) ◽  
pp. 1294-1305 ◽  
Author(s):  
Xiao-guang FAN ◽  
He YANG ◽  
Peng-fei GAO ◽  
Rui ZUO ◽  
Peng-hui LEI ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Hot Working ◽  
Two Phase ◽  
Α Phase

Efficiency of Microstructure Refinement in Ti-Based Alloys

2021 ◽  
Vol 1016 ◽  
pp. 1753-1758
Author(s):  
Sergey Zherebtsov ◽  
Nikita Stepanov ◽  
Gennady Salishchev
Keyword(s):  
Plastic Deformation ◽  
Chemical Composition ◽  
Titanium Alloys ◽  
Microstructure Evolution ◽  
Large Plastic Deformation ◽  
Two Phase ◽  
Microstructure Refinement ◽  
Kinetics Of ◽  
Rate Type ◽  
Lamellar Type

The influence of various factors on the efficiency of microstructure refinement in two-phase titanium alloys with respect to a well-known Ti-6Al-4V alloy was discussed. The kinetics of microstructure evolution in titanium alloys with a lamellar type α/β microstructure during large plastic deformation depends mainly on temperature and strain rate, type of the initial microstructure, thickness of the α lamellae, path of deformation and chemical composition. Each parameter should be controlled to provide the most efficient microstructure refinement during conventional metalforming methods.

Processing, Structure, Texture and Microtexture in Titanium Alloys

2012 ◽  
Vol 710 ◽  
pp. 66-84 ◽  
Author(s):  
Dipankar Banerjee ◽  
Adam L. Pilchak ◽  
James C. Williams
Keyword(s):  
Titanium Alloys ◽  
Single Phase ◽  
Thermomechanical Processing ◽  
Strong Dependence ◽  
Two Phase ◽  
Β Phase ◽  
Phase Fields ◽  
Deformation And Heat Treatment ◽  
Two Phases ◽  
The Individual

We review the effect of processing on structure and texture in titanium alloys, focusing on the understanding of this relationship that has evolved over the last decade. Thermomechanical processing cycles for these alloys involve deformation and heat treatment in single phase β and two phase, α+β, phase fields, and involves a complex interplay between deformation and recrystallization textures of the individual phases, textures arising from the crystallographic relationship between the two phases, and the scale of microstructure evolution. We explore these interactions and trace the strong dependence of thermomechanical pathways on the final structure and texture.

The Role of the Deformation Conditions in the Evolution of the Microstructure of the Ti-6Al-2Sn-4Zr-6Mo Alloy

2015 ◽  
Vol 641 ◽  
pp. 116-119 ◽  
Author(s):  
Janusz Krawczyk ◽  
Aneta Łukaszek-Sołek ◽  
Robert Dąbrowski
Keyword(s):  
Plastic Deformation ◽  
True Strain ◽  
Processing Temperature ◽  
Strain Rates ◽  
Two Phase ◽  
Β Phase ◽  
Fine Grain ◽  
Α Phase ◽  
Temperature Time

This work discusses the influence of the processing temperature, time and processing strain on the microstructure of the Ti6Al2Sn4Zr6Mo alloy. The Ti6Al2Sn4Zr6Mo alloy belongs to the two-phase (α+β) type of titanium alloys. The samples were compressed with the use of the Gleeble thermo-mechanical simulator at the temperatures of: 800, 900, 950, 1000 and 1100°C and at the strain rates of: 0.01; 0.1; 1; 10 and 100 s-1 to a total true strain of 1. The occurrence of the primary α phase in the Ti6Al2Sn4Zr6Mo alloy was investigated. The diagram showing the influence of the processing temperature and the strain rate on the dynamic recrystallization of the β phase was presented.The occurrence of the primary α phase precipitates blocks the grain growth. Therefore, the plastic deformation of this alloy should be carried out at a temperature at which the separation of the primary α phase occurs to finally obtain a material with a fine grain.

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