Hot Deformation Microstructure and Mechanism of Ti53311S Titanium Alloy

The hot deformation behaviors of a new Ti-6Al-2Nb-2Zr-0.4B titanium alloy in the strain rate range 0.01–10.0 s−1 and temperature range 850–1060 °C were evaluated using hot compressing testing on a Gleeble-3800 simulator at 60% of deformation degree. The flow stress characteristics of the alloy were analyzed according to the true stress–strain curve. The constitutive equation was established to describe the change of deformation temperature and flow stress with strain rate. The thermal deformation activation energy Q was equal to 551.7 kJ/mol. The constitutive equation was ε ˙=e54.41[sinh (0.01σ)]2.35exp(−551.7/RT). On the basis of the dynamic material model and the instability criterion, the processing maps were established at the strain of 0.5. The experimental results revealed that in the (α + β) region deformation, the power dissipation rate reached 53% in the range of 0.01–0.05 s−1 and temperature range of 920–980 °C, and the deformation mechanism was dynamic recovery. In the β region deformation, the power dissipation rate reached 48% in the range of 0.01–0.1 s−1 and temperature range of 1010–1040 °C, and the deformation mechanism involved dynamic recovery and dynamic recrystallization.

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Analysis of Hot Deformation Dynamics of TC18 Titanium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.747-748.878 ◽

2013 ◽

Vol 747-748 ◽

pp. 878-884 ◽

Cited By ~ 1

Author(s):

Qing Rui Wang ◽

Ai Xue Sha ◽

Xing Wu Li ◽

Li Jun Huang

Keyword(s):

Titanium Alloy ◽

Phase Transformation ◽

Flow Stress ◽

Strain Rate ◽

Hot Deformation ◽

Deformation Temperature ◽

Relationship Model ◽

Deformation Dynamics ◽

Deformation Mechanics ◽

Versus Strain

The effect of strain rate and deformation temperature on flow stress of TC18 titanium alloy was studied through heat simulating tests in 760~960 with temperature interval and the strain rate interval in 0.01~10s-1. Relationship model of flow stress versus strain was established and hot deformation mechanics of TC18 titanium alloy was analyzed. The results show that the flow stress reduces obviously as the deformation temperature increases or the strain rate decreases. Dynamic recovery occurs at high strain rate above phase transformation point, while dynamic recrystallization occurs at low strain rate as well as at the temperature below phase transformation point.

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Unified modelling of the flow behaviour and softening mechanism of a TC6 titanium alloy during hot deformation

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2018.03.120 ◽

2018 ◽

Vol 748 ◽

pp. 1031-1043 ◽

Cited By ~ 15

Author(s):

Junling Li ◽

Baoyu Wang ◽

He Huang ◽

Shuang Fang ◽

Ping Chen ◽

...

Keyword(s):

Titanium Alloy ◽

Hot Deformation ◽

Flow Behaviour ◽

Softening Mechanism

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Hot working of SP-700 titanium alloy with lamellar α + β starting structure using a processing map

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-1110405 ◽

2020 ◽

Vol 111 (4) ◽

pp. 297-306

Author(s):

Amir Hosein Sheikhali ◽

Maryam Morakkabati

Keyword(s):

Titanium Alloy ◽

Strain Rate ◽

Hot Deformation ◽

Processing Map ◽

Microstructural Analysis ◽

Shear Bands ◽

Alpha Phase ◽

Strain Rates ◽

Compression Tests ◽

Temperature Range

Abstract In this study, hot deformation behavior of SP-700 titanium alloy was investigated by hot compression tests in the temperature range of 700-9508C and at strain rates of 0.001, 0.1, and 1 s-1. Final mechanical properties of the alloy (hot compressed at different strain rates and temperatures) were investigated using a shear punch testing method at room temperature. The flow curves of the alloy indicated that the yield point phenomenon occurs in the temperature range of 800- 9508C and strain rates of 0.1 and 1 s-1. The microstructural analysis showed that dynamic globularization of the lamellar α phase starts at 7008C and completes at 8008C. The alpha phase was completely eliminated from b matrix due to deformation- induced transformation at 8508C. The microstructure of specimens compressed at 8508C and strain rates of 0.001 and 0.1 s-1showed the serration of beta grain boundaries, whereas partial dynamic recrystallization caused a necklace structure by increasing strain rate up to 1 s-1. The specimen deformed at 7008C and strain rate of 1 s-1was located in the instability region and localized shear bands formed due to the low thermal conductivity of the alloy. The processing map of the alloy exhibited a peak efficiency domain of 54% in the temperature range of 780-8108C and strain rates of 0.001- 0.008 s-1. The hot deformation activation energy of the alloy in the α/β region (305.5 kJ mol-1) was higher than that in the single-phase β region (165.2 kJ mol-1) due to the dynamic globularization of the lamellar a phase.

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Microstructure Evolution of near α Titanium Alloy during Multi-Step Thermomechanical Deformation Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1035.305 ◽

2021 ◽

Vol 1035 ◽

pp. 305-311

Author(s):

Qing Shan Liu ◽

Bo Long Li ◽

Tong Bo Wang ◽

Cong Cong Wang ◽

Peng Qi ◽

...

Keyword(s):

Titanium Alloy ◽

High Temperature ◽

Hot Deformation ◽

Deformation Temperature ◽

Strain Curve ◽

Optical Microscope ◽

Phase Content ◽

Β Phase ◽

Α Phase ◽

Gleeble 3500

A new type of near α high temperature titanium alloy of Ti-Al-Sn-Zr-Mo-Si-Er was studied. The samples with different primary α phase content were prepared by solid solution at 950 °C/1 h—1010 °C/1 h. The multi-step hot compression experiments were carried out by Gleeble-3500 in a sequence of upper region of α + β phase, then followed by lower region of α + β phase. The effects of primary α phase content and deformation temperature on the microstructure of the alloy were studied by means of true stress-strain curve and optical microscope. The results show that the content of primary α phase gradually decreases from 45.4% at 950°C to 0% at 1010°C. As the deformation temperature decreases from 940°C to 900°C, the content of α phase increases gradually from 65% to 94%, which is changed from dynamic recrystallization to deformed structure elongated along RD direction. It is found that the arrangement of α phase along RD direction is the longest at 920°C. With the increase of the deformation temperature in the multi-step high temperature region from 970°C to 990°C, the width of deformed α phase decreases from 3.64 μm at 970°C to 2.71 μm at 990°C. The optimized microstructure is composed of 20% primary α phase arranged along RD direction. This process has a certain potential in the process of hot deformation of the alloy. Key words: high temperature titanium alloy, primary α phase, multi-step hot deformation

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Microstructure and texture evolution of a near β titanium alloy Ti-7333 during continuous cooling hot deformation

Progress in Natural Science Materials International ◽

10.1016/j.pnsc.2019.01.003 ◽

2019 ◽

Vol 29 (1) ◽

pp. 50-56 ◽

Cited By ~ 3

Author(s):

Jiahao Chen ◽

Jinshan Li ◽

Bin Tang ◽

Yi Chen ◽

Hongchao Kou

Keyword(s):

Titanium Alloy ◽

Hot Deformation ◽

Texture Evolution ◽

Continuous Cooling

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High-Temperature Deformation Behavior and Microstructural Characterization of Ti-35421 Titanium Alloy

Materials ◽

10.3390/ma13163623 ◽

2020 ◽

Vol 13 (16) ◽

pp. 3623 ◽

Cited By ~ 2

Author(s):

Danying Zhou ◽

Hua Gao ◽

Yanhua Guo ◽

Ying Wang ◽

Yuecheng Dong ◽

...

Keyword(s):

Titanium Alloy ◽

Dynamic Recrystallization ◽

Strain Rate ◽

Hot Deformation ◽

Deformation Behavior ◽

Deformation Temperature ◽

Phase Region ◽

Temperature Deformation ◽

Β Phase ◽

Α Phase

A self-designed Ti-35421 (Ti-3Al-5Mo-4Cr-2Zr-1Fe wt%) titanium alloy is a new type of low-cost high strength titanium alloy. In order to understand the hot deformation behavior of Ti-35421 alloy, isothermal compression tests were carried out under a deformation temperature range of 750–930 °C with a strain rate range of 0.01–10 s−1 in this study. Electron backscatter diffraction (EBSD) was used to characterize the microstructure prior to and post hot deformation. The results show that the stress–strain curves have obvious yielding behavior at a high strain rate (>0.1 s−1). As the deformation temperature increases and the strain rate decreases, the α phase content gradually decreases in the α + β phase region. Meanwhile, spheroidization and precipitation of α phase are prone to occur in the α + β phase region. From the EBSD analysis, the volume fraction of recrystallized grains was very low, so dynamic recovery (DRV) is the dominant deformation mechanism of Ti-35421 alloy. In addition to DRV, Ti-35421 alloy is more likely to occur in continuous dynamic recrystallization (CDRX) than discontinuous dynamic recrystallization (DDRX).

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