scholarly journals The Effect of Initial Annealing Microstructures on the Forming Characteristics of Ti–4Al–2V Titanium Alloy

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 576 ◽  
Author(s):  
Bin Yan ◽  
Hongbo Li ◽  
Jie Zhang ◽  
Ning Kong
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Room Temperature ◽  
Constant Strain Rate ◽  
Annealing Treatment ◽  
Fracture Morphology ◽  
Sem Analysis ◽  
Α Phase ◽  
Plastic Forming ◽  
Forming Characteristics

In this study, the effect of initial annealing microstructure of Ti–4Al–2V (TA17) alloy on forming characteristic was studied, so as to provide a basis for quality control of plastic forming of titanium alloy parts. The titanium alloy always undergoes annealing treatment before forming, due to different microstructures present different mechanical properties. The TA17 with different microstructures are obtained by means of various annealing treatment temperatures. The tensile behavior of TA17 is investigated at room temperature and 900 °C under constant strain rate of 0.01 s−1. The experimental results show that the mechanical properties of TA17 are sensitive to the initial microstructure before deformation. The microstructure of TA17 at 850 °C (2 h) is the equiaxed primary α-phase after the annealing process. It exhibits good plasticity at room temperature. This phenomenon is also confirmed from fracture morphology from the scanning electron microscope (SEM) analysis. At 900 °C, which is a high tensile temperature, the alloy with equiaxed primary α-phase performs outstanding plasticity compared with other microstructures. This work establishes a good understanding on the relationship between the mechanical properties and microstructures of TA17 at a wide temperature range.

Influence of Isothermal Forging Temperature on Microstructure and Tensile Properties of Ti-5.8Al-4.0Sn-4.0Zr-0.7Nb-0.4Si-1.5Ta Near-α Titanium Alloy

2010 ◽  
Vol 97-101 ◽  
pp. 153-157
Author(s):  
Tao Wang ◽  
Hong Zhen Guo ◽  
Jian Hua Zhang ◽  
Ze Kun Yao
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Titanium Alloy ◽  
Tensile Properties ◽  
Room Temperature ◽  
Volume Fraction ◽  
Constant Strain Rate ◽  
Isothermal Forging ◽  
Α Phase ◽  
Transus Temperature

The microstructures and room temperature and 600°C tensile properties of Ti-5.8Al-4.0Sn-4.0Zr-0.7Nb -0.4Si-1.5Ta alloy after isothermal forging have been studied. The forging temperature range was from 850°C to 1075°C, and the constant strain rate of 8×10-3/S-1 was adopted. With the increase of forging temperature, the volume fraction of primary α phase decreased and the lamellar α phase became thicker when the temperatures were in range of 850°C -1040°C; The grain size became uneven and the α phase had different forms when the forging temperature was 1040°C and 1075°C respectively; The tensile strength was not sensitive to the temperature and the most difference was within 20MPa. Tensile strength and yield strength attained to the maximum when temperature was 1020°C; the ductility decreased with the increase of forging temperature, and this trend became more obvious if forging temperature was above the β-transus temperature.

Influences of Solution Temperatures on Microstructure and Mechanical Properties of near α Titanium Alloy

2021 ◽  
Vol 1035 ◽  
pp. 89-95
Author(s):  
Chao Tan ◽  
Zi Yong Chen ◽  
Zhi Lei Xiang ◽  
Xiao Zhao Ma ◽  
Zi An Yang
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
High Temperature ◽  
Room Temperature ◽  
Solution Temperature ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Β Phase ◽  
Α Phase ◽  
New Type

A new type of Ti-Al-Sn-Zr-Mo-Si series high temperature titanium alloy was prepared by a water-cooled copper crucible vacuum induction melting method, and its phase transition point was determined by differential thermal analysis to be Tβ = 1017 °C. The influences of solution temperature on the microstructures and mechanical properties of the as-forged high temperature titanium alloy were studied. XRD results illustrated that the phase composition of the alloy after different heat treatments was mainly α phase and β phase. The microstructures showed that with the increase of the solution temperature, the content of the primary α phase gradually reduced, the β transformation structure increased by degrees, then, the number and size of secondary α phase increased obviously. The tensile results at room temperature (RT) illustrated that as the solution temperature increased, the strength of the alloy gradually increased, and the plasticity decreased slightly. The results of tensile test at 650 °C illustrated that the strength of the alloy enhanced with the increase of solution temperature, the plasticity decreased first and then increased, when the solution temperature increased to 1000 °C, the alloy had the best comprehensive mechanical properties, the tensile strength reached 714.01 MPa and the elongation was 8.48 %. Based on the room temperature and high temperature properties of the alloy, the best heat treatment process is finally determined as: 1000 °C/1 h/AC+650 °C/6 h/AC.

Microstructure and Mechanical Properties of a Novel Ti-6.5Al-2Sn-4Zr-1.5Mo-2Nb-0.25Fe-0.2Si High-Temperature Titanium Alloy

2020 ◽  
Vol 993 ◽  
pp. 351-357
Author(s):  
Ming Yu Zhao ◽  
Xiao Yun Song ◽  
Wen Jing Zhang ◽  
Yu Wei Diao ◽  
Wen Jun Ye ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Room Temperature ◽  
Annealing Treatment ◽  
Tensile Tests ◽  
Electron Backscattered Diffraction ◽  
Two Phase ◽  
Bimodal Structure ◽  
Α Phase ◽  
Microstructure And Mechanical Properties

The Ti-6.5Al-2Sn-4Zr-1.5Mo-2Nb-0.25Fe-0.2Si (wt%) alloy is a novel two-phase high temperature alloy for short-term application. The effects of different heat treatments on the microstructure and mechanical properties were investigated through electron probe microanalysis (EPMA), optical microcopy (OM), scanning electron microscope (SEM), electron backscattered diffraction (EBSD) and tensile tests at room temperature and 650°C. Subjected to the annealing treatment at α+β region (1010 °C/2 h, FC to 990 °C+990 °C/2 h, AC), the microstructure was composed of bimodal structure, which consists of equiaxed primary α (αp) phase and lamellar transformed β (βt) structure. As a strong β stabilizer, the content of Fe in α phase is much less than that in β phase. Annealing at β region (1040 °C/2 h, AC) resulted in the formation of widmannstatten structure, consisting of coarse raw β grain and secondary α phase precipitated on the β grain. With respect to the tensile property, different heat-treated alloys obtained similar strength. However, widmannstatten structure was characterized by lower plasticity, with the elongation only half that of bimodal structure. The fracture characteristics at room temperature for the alloy with bimodal structure and widmannstatten structure are dominated by ductile fracture and cleavage fracture, respectively.

scholarly journals Nanoindentation and Microstructure in the Shear Band in a Near Beta Titanium Alloy Ti-5Al-5Mo-5V-1Cr-1Fe

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4065
Author(s):  
Bingfeng Wang ◽  
Xu Ding ◽  
Ying Mao ◽  
Lanyi Liu ◽  
Xiaoyong Zhang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Titanium Alloy ◽  
Phase Transformation ◽  
Shear Band ◽  
Cryogenic Temperature ◽  
Room Temperature ◽  
Beta Titanium Alloy ◽  
Α Phase ◽  
Beta Titanium

Shear localization is the main deformation mode for the near beta titanium alloy Ti-5Al-5Mo-5V-1Cr-1Fe loaded at high strain rates at either room temperature or cryogenic temperature. Nanoindentation, transmission electron microscopy, and high-resolution electron microscopy technique are applied to character the microstructure features and mechanical properties in the shear band of near beta titanium alloy. A white and straight band is observed in the shear region. Both microhardness and nanoindentaion hardness in the shear region are inferior to those in matrix. The different microstructure in the edge and the center in the shear band contribute to different mechanical properties. The plasticity of the entire shear band is almost homogenous when specimens are deformed at the cryogenic temperature. Rotational dynamic recrystallization is responsible for the formation of the ultrafine grains in the shear band. The edge of the shear band is composed of elongated grains, while there are ultrafine equiaxed grains in the center of the shear band. Deformation temperature has significant influence on the process of the grain refinement and the phase transformation in the shear band (SB). The grain sizes of the shear band in the specimen deformed at room temperature are larger than those in the specimens deformed at cryogenic temperature. The shear band consists of α phase grains in the specimen deformed at room temperature, and the shear band consists of α phase and lath-like α′ phase grains in the specimen deformed at cryogenic temperature. Finally, the mechanisms for phase transformation in the shear band are illustrated.

Influence of Duplex Annealing on the Microstructure and Mechanical Properties of Ti62421S Titanium Alloy Plate

2015 ◽  
Vol 816 ◽  
pp. 804-809 ◽  
Author(s):  
Xiao Yun Song ◽  
Yong Ling Wang ◽  
Wen Jing Zhang ◽  
Song Xiao Hui ◽  
Wen Jun Ye
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Volume Fraction ◽  
Annealing Treatment ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Alloy Plate ◽  
Β Phase ◽  
Α Phase ◽  
Microstructure And Mechanical Properties

The effects of different duplex annealing treatments on the microstructure and mechanical properties of Ti62421S alloy plate were studied by optical microscope (OM), scanning electron microscope (SEM), electron probe microanalysis (EPMA) and tensile tests, The experimental results indicated that the original microstructure of Ti62421S was composed of primary α phase (αp) and intergranular β phase. With the increase of first-stage annealing temperature, the volume fraction of equiaxed αp phase decreased. In contrast, the content of transformed β structure (βt) increased, and the width of lamellar secondary α phase (αs) in βt increased. Consequently, the yield strength (σ0.2) and ultimate tensile strength (σb) at room temperature and 600°C increased, while the elongation (δ5) declined. After 1000°C/2h/AC+ 600°C/2h/AC duplex annealing treatment, Ti62421S alloy plate showed superior tensile properties. The values of σb and δ5 at room temperature reached 1133MPa and 6%, as well as the value of σb at 600°C exceeded 710MPa.

scholarly journals Aging of the β21S Titanium Alloy

2016 ◽  
Vol 258 ◽  
pp. 550-553
Author(s):  
Héloise Vigié ◽  
Aurélie Soula ◽  
Bernard Viguier
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Elevated Temperature ◽  
Thermal Treatment ◽  
Room Temperature ◽  
Tensile Tests ◽  
Low Density ◽  
Phase Precipitation ◽  
Α Phase ◽  
Resistance To Oxidation

Ti-β21S is a β-metastable titanium alloy, currently used in industries such as aeronautics, because of its cold formability, good mechanical properties at elevated temperature, low density and its strong resistance to oxidation. This alloy is hardened by an α-phase precipitation in the β-matrix. The purpose of the present research is to establish the effect of aging on the microstructure and mechanical properties of Ti-β21S. Different thermal aging tests have been carried out at 600°C and at 650°C for 500 hours in laboratory air. The evolution of the microstructure has been reported after each thermal treatment and associated with room temperature tensile tests results.

Effect of Hot Processing on Mircrostructure and Properties of Flat Billets of TA15 Titanium Alloy

2021 ◽  
Vol 1016 ◽  
pp. 906-910
Author(s):  
Xin Hua Min ◽  
Cheng Jin
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Titanium Alloy ◽  
High Temperature ◽  
Room Temperature ◽  
High Strength ◽  
Slow Cooling ◽  
Microstructure And Mechanical Properties ◽  
Ta15 Titanium Alloy ◽  
The Ideal

In this paper,effect of the different forging processes on the microstructure and mechanical properties of the flat flat billets of TA15 titanium alloy was investigated.The flat billiets of 80 mm×150 mm×L sizes of TA15 titanium alloy are produced by four different forging processes.Then the different microstrure and properties of the flat billiets were obtained by heat treatment of 800 °C~850 °C×1 h~4h.The results show that, adopting the first forging temperature at T1 °C、slow cooling and the second forging temperature at T2°C 、quick cooling, the primary αphases content is just 10%, and there are lots of thin aciculate phases on the base. This microstructure has both high strength at room temperature and high temperature, while the properties between the cross and lengthwise directions are just the same. So the hot processing of the first forging temperature at T1 °C、slow cooling and the second forging temperature at T2°C 、quick cooling is choosed as the ideal processing for production of aircraft frame parts.

scholarly journals Feasibility study of a novel hot stamping process for Ti6Al4V alloy

2018 ◽  
Vol 190 ◽  
pp. 08001
Author(s):  
Mateusz Kopec ◽  
Kehuan Wang ◽  
Yaoqi Wang ◽  
Liliang Wang ◽  
Jianguo Lin
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Phase Transformation ◽  
New Technology ◽  
Hot Stamping ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Ti6al4v Titanium Alloy ◽  
Stamping Process ◽  
Forming Tools

To investigate the feasibility of a novel hot stamping process for the Ti6Al4V titanium alloy using low temperature forming tools, mechanical properties of the material were studied using hot tensile tests at a temperature range of 600 - 900°C with a constant strain rate of 1s-1. Hot stamping tests were carried out to verify the feasibility of this technology and identify the forming window for the material. Results show that when the deformation temperature was lower than 700°C, the amount of elongation was less than 20%, and it also had little change with the temperature. However, when the temperature was higher than 700°C, a good ductility of the material can be achieved. During the forming tests, parts failed at lower temperatures (600°C) due to the limited formability and also failed at higher temperatures (950°C) due to the phase transformation. The post-form hardness firstly decreased with the temperature increasing due to recovery and then increased due to the phase transformation. Qualified parts were formed successfully between temperatures of 750 - 850°C, which indicates that this new technology has a great potential in forming titanium alloys sheet components.

Beta-titanium biomedical alloy: effect of thermal processing on mechanical properties

2012 ◽  
Vol 57 (3) ◽  
pp. 753-757 ◽  
Author(s):  
K.V. Sudhakar ◽  
K. Konen ◽  
K. Floreen
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Testing Machine ◽  
Solution Treatment ◽  
High Strength ◽  
Fracture Morphology ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Digital Microscope ◽  
Aging Conditions

A new β-titanium alloy (Ti-3Al-5V-6Cr-3Mo-3Zr) was investigated as a function of heat treatment to evaluate its mechanical properties. The cold drawn beta-titanium alloy was subjected to β-annealing as well as solution treatment and aging treatments. The mechanical properties were evaluated using MTS Landmark-servo hydraulic Universal Testing Machine. The beta-titanium alloy demonstrated an excellent combination of strength and ductility for both β-annealing and solution treatment and aging conditions. The influence of thermal treatments on microstructure was studied with HiRox digital microscope. The fracture morphology investigated revealed predominantly cup and cone/dimpled fracture surface features demonstrating excellent toughness in addition to high strength and low stiffness that are suitable for biomedical applications.

Effect of Aging Process on Microstructure and Room Temperature Ductility of TB6 Titanium Alloy

2014 ◽  
Vol 1061-1062 ◽  
pp. 567-570
Author(s):  
Cui Ye ◽  
Fei Zhao ◽  
Fang Zhou ◽  
Ni Li ◽  
Jun Shuai Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Titanium Alloy ◽  
Aging Time ◽  
Aging Temperature ◽  
Aging Process ◽  
Room Temperature ◽  
Room Temperature Ductility ◽  
Tb6 Titanium Alloy

Microstructure and room temperature ductility of the TB6 titanium alloy was investigated by varying the aging temperature and the aging time.The results show that, the alloy’s contraction of area increases while the tensile strength firstly increases and then decreases by raising their aging temperature. In general, the ductility of the samples increases and the strength decreases with the increasing aging time. The optimum mechanical properties are obtained by aging at 650 °C for 2 h.

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