Effect of Primary α Phase Content on Creep Property of High Temperature Titanium Alloy

2020 ◽  
Vol 993 ◽  
pp. 217-222
Author(s):  
Cong Cong Wang ◽  
Bo Long Li ◽  
Xu Qiao ◽  
Tong Bo Wang ◽  
Peng Qi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
High Temperature ◽  
Creep Test ◽  
Creep Resistance ◽  
Volume Fraction ◽  
Creep Property ◽  
Solution Temperature ◽  
Dislocation Configuration ◽  
Α Phase

The effect of the primary α content and precipitate on the creep resistance of a high-temperature titanium alloy with a small amount of Hf addition were studied. The microstructures with different primary α contents were prepared by the heat treatment of 920~1010 °C /1 h+700 °C/5 h, and the creep test (600 °C/150 MPa/100 h) was carried out. The interaction between the precipitation phase and the dislocation configuration was analyzed. The results showed that with the increase of solution temperature, the volume fraction of primary α phase decreased from 44.9% at 920 °C to 0% at 1010 °C, and the steady state creep rate of the alloy decreased from 60.60×10-4%/h to 3.72×10-4%/h, indicating that the creep property was significantly improved with the decrease of solution temperature. The basket structure with optimal creep resistance was obtained under the heat treatment of 1010 °C/1 h+700 °C/5 h. It is believed that during the high temperature creep test, the precipitated α2 phase and the hafnium-containing silicide hinder the dislocation motion in α crystal and the phase boundary, thereby improving the creep resistance of the alloy.

Multi-Scale Microstructure Regulation Technology of Near-α High Temperature Titanium Alloy

2019 ◽  
Vol 944 ◽  
pp. 92-98
Author(s):  
Xu Qiao ◽  
Bo Long Li ◽  
Tong Bo Wang ◽  
Zuo Ren Nie
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
High Temperature ◽  
Process Analysis ◽  
Solution Treatment ◽  
Solution Temperature ◽  
Microstructure And Properties ◽  
Equiaxed Structure ◽  
Α Phase ◽  
Α2 Phase

The served harsh environment of advanced aircraft engine puts forward higher requirements for high temperature titanium alloy performance. The optimized heat treatment technology provides effective theoretical basis for improving the microstructure and properties of high temperature titanium alloys. In this paper, we study the influence of different heat treatment systems on microstructure and mechanical properties of high temperature alloy with equiaxed structure, in order to obtain the corresponding relationship between the process and the microstructure performance of the alloy and the optimal heat treatment process. Analysis the effect of solution treatment on the primary α phase quantitatively by optical microscope and Image-Pro-Plus 6.0 software based on the forged high temperature titanium alloy in α+β phase region. Observe the precipitation of α2 phase and silicide by TEM, optimize the aging process according to hardness test. The results show that the content of primary a phase decrease from 63.3% at 920°C to 15.3% at 990°C with the increase of solution temperature. When the temperature rises to 980~990°C, the structure changes from equiaxed structure to α+β duplex microstructure. And change into lamellar structure when the solution temperature raise to 1010°C. The secondary α phase precipitates more fully when the aging temperature increases. And with increasing aging time, the trend of α2 phase growth become more significantly. The optimum heat treatment system obtained in this experimental is 990°C/1h/AC+700°C/5h/AC, and the α phase is about 15.3%. Hence, the excellent microstructure and properties match has been obtained.

scholarly journals The Effect of Heat Treatment on the Microstructure and Mechanical Properties of the Novel Low-Cost Ti-3Al-5Mo-4Cr-2Zr-1Fe Alloy

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3798
Author(s):  
Meng Sun ◽  
Dong Li ◽  
Yanhua Guo ◽  
Ying Wang ◽  
Yuecheng Dong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aging Time ◽  
Volume Fraction ◽  
Low Cost ◽  
Solution Treatment ◽  
Solution Temperature ◽  
The Novel ◽  
Α Phase ◽  
The Cost

In order to reduce the cost of titanium alloys, a novel low-cost Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) titanium alloy was developed. The influence of heat treatment on the microstructure characteristics and mechanical properties of the new alloy was investigated. The results showed that the microstructure of Ti-35421 alloy consists of a lamina primary α phase and a β phase after the solution treatment at the α + β region. After aging treatment, the secondary α phase precipitates in the β matrix. The precipitation of the secondary α phase is closely related to heat treatment parameters—the volume fraction and size of the secondary α phase increase when increasing the solution temperature or aging time. At the same solution temperature and aging time, the secondary α phase became coarser, and the fraction decreased with increasing aging temperature. When Ti-35421 alloy was solution-treated at the α + β region for 1 h with aging surpassing 8 h, the tensile strength, yield strength, elongation and reduction of the area were achieved in a range of 1172.7–1459.0 MPa, 1135.1–1355.5 MPa, 5.2–11.8%, and 7.5–32.5%, respectively. The novel low-cost Ti-35421 alloy maintains mechanical properties and reduces the cost of materials compared with Ti-3Al-5Mo-5V-4Cr-2Zr (Ti-B19) alloy.

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.

Effect of Heat Treatment on the Microstructure and Dynamic Behavior of Ti-10V-2Fe-3Al Alloy

2018 ◽  
Vol 910 ◽  
pp. 155-160 ◽  
Author(s):  
An Jin Liu ◽  
Lin Wang ◽  
Hua Xiang Dai
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Titanium Alloy ◽  
Yield Strength ◽  
Dynamic Compression ◽  
Aging Treatment ◽  
Solution Temperature ◽  
Β Phase ◽  
Solution Treated ◽  
Α Phase

Microstructure evolution and compression property of Ti-10V-2Fe-3Al titanium alloy were studied in this paper. Solution treatments were performed at temperature ranging from 710°C to 830°C and some followed by aging treatment. Ti-10V-2Fe-3Al alloys with α+β phase show higher mechanical properties compared with single β phase alloy. With the increase of solution temperature, the content of equiaxed α phase decrease. Consequently, the strength of the alloy increases while the plasticity drops down. The highest yield strength value of 1668 MPa was obtained in the sample treated by 770°C solution treated for 2 hours then water quenched and followed by 520°C aging for 8 hours then air cooled. The stress induced martensite α'' phase appeared after SHPB dynamic compression in the sample solution treated at 830°C.

Microstructures and Mechanical Properties of a New Type of High Temperature Titanium Alloy

2020 ◽  
Vol 993 ◽  
pp. 208-216
Author(s):  
Ya Peng Cui ◽  
Zi Yong Chen ◽  
Xiao Zhao Ma ◽  
Ying Ying Liu ◽  
Zhi Lei Xiang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
High Temperature ◽  
High Strength ◽  
Solution Temperature ◽  
Β Phase ◽  
Α Phase ◽  
Heat Treated ◽  
New Type ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of a new type near α high temperature titanium alloy Ti-6.5Al-2.5Sn-9Zr-0.5Mo-0.25Si-1Nb-1W-0.3Re (wt. %) (denoted as TA6.5) were investigated. It was observed that the microstructure of forged TA6.5 mainly consisted of deformed lamellar α phase, small amount of equiaxed α phase, and residual β phase, exhibiting high strength and comparatively low elongation. Three different heat treatments processes were performed on forged TA6.5. The results showed that all heat treated alloys displayed high tensile strengths, and the values of strength parameters were almost unchanged with the increasing solution temperature, ascribing to the combination effects of decreasing primary α phase and increasing contents and widths of secondary α phase and lamellas. The tensile elongations of heat treated alloys tested at 650 °C decreased slightly with the increasing solution temperature, which is due to the increased width of secondary α lamellas and the generation of coarse grain boundary α phase. TA6.5 treated in the process of 990 °C/1 h/AC+700 °C/4 h/AC exhibited excellent comprehensive mechanical properties, i.e. the ultimate tensile strength of 829 MPa, yield strength of 707 MPa and elongation of 18.73% respectively.

Effect of Heat Treatment Process on Microstructure of a New Metastable β Titanium Alloy

2020 ◽  
Vol 993 ◽  
pp. 223-229
Author(s):  
Xin Nan Wang ◽  
Yun Peng Xin ◽  
Ming Bing Li ◽  
Zhi Shou Zhu ◽  
Guo Qun Zhao
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Titanium Alloy ◽  
Aging Temperature ◽  
Treatment Process ◽  
Solution Temperature ◽  
Heat Treatment Process ◽  
Α Phase ◽  
Average Grain Size ◽  
Staggered Arrangement

The effects of solution temperature and aging temperature on microstructure of a new metastable β titanium alloy were studied. With the decrease of solution temperature, β grain size gradually decreased. When the solution temperature dropped to 780°C, the average grain size was about 10 μm. As the aging temperature increased from 500 °C to 560 °C, the secondary α phase increased. The nucleation of the secondary α phase within the grain was uniform, and its relationship with the β matrix was satisfied with Burgers. With the extension of aging time, the amount of the secondary α phases increased obviously, and they had a staggered arrangement with each other, presenting the phenomenon of the tensile strength increasing continuously. The strength level reached to 1500 MPa after aging at 500 °C for 8 h.

scholarly journals Effect of Heat Treatment Conditions on the Morphology of α Phase and Mechanical Properties In Ti-10V-2Fe-3Al Titanium Alloy/ Wpływ Warunków Obróbki Cieplnej Na Morfologie Fazy α I Własności Mechaniczne W Stopie Tytanu Ti-10V-2Fe-3Al

2014 ◽  
Vol 59 (4) ◽  
pp. 1269-1273 ◽  
Author(s):  
R. Bogucki ◽  
K. Mosór ◽  
M. Nykiel
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Titanium Alloy ◽  
Martensitic Transformation ◽  
Volume Fraction ◽  
Heating Time ◽  
Α Phase ◽  
Microstructure And Mechanical Properties ◽  
Treatment Conditions

Abstract The influence of heat treatment on the microstructure and mechanical properties was studied in the Ti-10V-2Fe-3Al titanium alloy for two heat treatment schemes (α + β) and β + (β + α), which resulted in different morphologies of the α phase. Scheme I resulted in the α-phase of globular morphology, whose volume fraction did not change much during annealing. Scheme II led to obtaining a needle-like α-phase, whose amount increased together with heating time. The phenomenon of stress-induced martensitic transformation was observed in the material with needle-like morphology annealed for 15 and 30 min. Longer times of annealing effected in the decay of that transformation, provided the volume fraction of α-phase exceeded 50%.

Ti-5Al-4FeCr

Alloy Digest ◽  
1969 ◽  
Vol 18 (6) ◽  
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Titanium Alloy ◽  
High Temperature ◽  
Heat Treating ◽  
Age Hardening ◽  
Temperature Performance ◽  
Alpha Beta ◽  
Hardening Heat Treatment

Abstract Ti-5A1-4FeCr is an alpha-beta type titanium alloy recommended for airframe components. It responds to an age-hardening heat treatment. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ti-58. Producer or source: Titanium alloy mills.

The Effect of Isothermal Forging Process Parameters on the Microstructure and the Properties of TA15 Near α Titanium Alloy

2007 ◽  
Vol 26-28 ◽  
pp. 367-371
Author(s):  
Hong Zhen Guo ◽  
Zhang Long Zhao ◽  
Bin Wang ◽  
Ze Kun Yao ◽  
Ying Ying Liu
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Tensile Properties ◽  
Process Parameters ◽  
Spherical Shape ◽  
Deformation Degree ◽  
Isothermal Forging ◽  
Forging Process ◽  
Α Phase ◽  
Strip Shape

In this paper the effect of isothermal forging process parameters on the microstructure and the mechanical properties of TA15 titanium alloy was researched. The results of the tests indicate that, in the range of temperature of 850 °C~980 °C and deformation degree of 20%~60%, with the increase of temperature or deformation, as the reinforcement of deformation recrystallization, the primary α-phase tends to the spherical shape and secondary α-phase transforms from the acicular shape to fine and spherical shape with disperse distribution, which enhance the tensile properties at room and high temperature. With the increment of forging times, the spheroidization of primary α-phase aggrandizes and secondary α-phase transforms from spherical and acicular shape to wide strip shape, which decrease the tensile properties at room and high temperature. The preferable isothermal forging process parameters are temperature of 980 °C, deformation degree of 60%, and few forging times.

Creep Behavior of a 4.5% Re Nickel-Base Single Crystal Superalloy at High Temperature

2015 ◽  
Vol 750 ◽  
pp. 139-144 ◽  
Author(s):  
De Long Shu ◽  
Su Gui Tian ◽  
Xin Ding ◽  
Jing Wu ◽  
Qiu Yang Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Single Crystal ◽  
Deformation Mechanism ◽  
Creep Property ◽  
Single Crystal Superalloy ◽  
Micro Cracks ◽  
Initiation And Propagation ◽  
Temperature Ranges ◽  
Nickel Base

By means of heat treatment and creep property measurement, an investigation has made into the creep behaviors of a containing 4.5% Re nickel-base single crystal superalloy at high temperature. Results show that the elements W, Mo and Re are enriched in the dendrite arm regions, the elements Al, Ta, Cr and Co are enriched in the inter-dendrite region, and the segregation extent of the elements may be obviously reduced by means of heat treatment at high temperature. In the temperature ranges of 1070--1100 °C, the 4.5% Re single crystal nickel-based superallloy displays a better creep resistance and longer creep life. The deformation mechanism of the alloy during steady state creep is dislocations slipping in the γ matrix and climbing over the rafted γ′ phase. In the later stage of creep, the deformation mechanism of alloy is dislocations slipping in the γ matrix, and shearing into the rafted γ′ phase, which may promote the initiation and propagation of the micro-cracks at the interfaces of γ/γ′ phases up to the occurrence of creep fracture.

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