Variation of Hardness with Microstructure Evolutions in Metastable β Titanium Alloy TIMETAL®LCB

2007 ◽  
Vol 561-565 ◽  
pp. 2067-2070 ◽  
Author(s):  
Tatsuaki Sakamoto ◽  
Kiyomichi Nakai ◽  
Munehiro Maeda ◽  
Sengo Kobayashi
Keyword(s):  
Titanium Alloy ◽  
Orientation Relationship ◽  
Aging Time ◽  
Aging Temperature ◽  
Solution Treatment ◽  
Alpha Phase ◽  
Number Density ◽  
Hardness Variation ◽  
Ω Phase ◽  
Α Phase

Microstructure evolutions and hardness variation during aging in metastable β titanium alloy TIMETAL®LCB have been examined. In as-quenched specimen after solution treatment, athermal ω phase formed. Isothermal ω phase formed during aging at 623 K, and α phase formed after precipitation of isothermal ω phase during aging at 673 and 773 K. Alpha phase nucleated at isothermal ω phase, and had the orientation relationship with β and ω, (111)β//(0001)ω//(1120 )α and [10 1 ]β//[1120 ]ω//[0001]α . During aging at 873 K, α phase formed without isothermal ω phase. Hardness increased with increasing aging time and decreasing aging temperature, partly because number density of isothermal ω or α precipitates increased with increasing aging time and decreasing aging temperature.

scholarly journals Evolution of Secondary α Phase during Aging Treatment in Novel near β Ti-6Mo-5V-3Al-2Fe Alloy

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2283 ◽  
Author(s):  
Haoyu Zhang ◽  
Chuan Wang ◽  
Siqian Zhang ◽  
Ge Zhou ◽  
Lijia Chen
Keyword(s):  
Mechanical Properties ◽  
Aging Temperature ◽  
Aging Process ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Subsequent Aging ◽  
Particle Spacing ◽  
Ω Phase ◽  
Α Phase ◽  
High Ultimate Tensile Strength

Evolution of secondary α phase during aging treatment of a novel near β titanium alloy Ti-6Mo-5V-3Al-2Fe(wt.%) was studied by OM, SEM, and TEM. Results indicated that size and distribution of secondary α phase were strongly affected by aging temperature and time. Athermal ω phase formed after super-transus solution treatment followed by water quenching, and promoted nucleation of needle-like intragranular α in subsequent aging process. When aged at 480 °C, fine scaled intragranular α with small inter-particle spacing precipitated within β grains and high ultimate tensile strength above 1500 MPa was achieved. When the aging temperature increased, the size and inter-particle spacing of intragranular α increased and made the strength reduce, but the ductility got improved. When aging temperature reached as high as 600 °C, ω phase disappeared and intragranular α coarsened obviously, resulting in serious decrease of strength. While mutually parallel Widmanstätten α laths formed at the vicinity of β grain boundaries and grew into the internal area of β grains, and significant improvement of ductility was achieved. As the aging time increased from 4 h to 16 h at 600 °C, the intragranular α grew slightly and brought about minor change of mechanical properties.

Microstructure and Property of a New Metastable β Titanium Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 932-936 ◽  
Author(s):  
Xin Nan Wang ◽  
Yue Fei ◽  
Xiao Hu Zhou ◽  
Zhi Shou Zhu ◽  
Jun Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Titanium Alloy ◽  
Aging Temperature ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Optical Microscope ◽  
Solution Treated ◽  
Α Phase ◽  
Scanning Electron

The evolution regularities of microstructure and property of a new metastable β titanium alloy with different solution treatment and aging treatment were studied using optical microscope (OM), scanning electron microscopy (SEM) and tensile test. The results show that, the volume fraction of primary α phase decreases and globularization of α phase occurs with the increasing aging temperature from 540 to 580 and solution treated temperature from 800 to 820. When the solution treated temperature is 820, the acicular secondary α phase precipitates along β grain boundary. The strength of the investigated alloy increases and the ductility decreases with the solution treated temperature increasing. While the strength of the investigated alloy increases and the ductility decreases with the aging temperature decreasing.

Thermal Stability and Mechanical Properties of Ti-15-3 Titanium Alloy

2016 ◽  
Vol 849 ◽  
pp. 232-237 ◽  
Author(s):  
Qing Rui Wang ◽  
Xing Wu Li ◽  
Ai Xue Sha ◽  
Xin Qing Zhao ◽  
Yong Qi Zhu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Titanium Alloy ◽  
Aging Time ◽  
Β Phase ◽  
Ω Phase ◽  
Microstructure Stability ◽  
Α Phase ◽  
Strength And Ductility

The microstructure stability and tensile properties of Ti-15-3 titanium alloy were investigated by aging the alloy at different conditions. The results showed that when the temperature was below 250°C, ω phase precipitates and the tensile strength increased with increasing aging time. Although there were a little of ω phase after aging at 200C for 1000h, Ti-15-3 alloy still presented good strength and ductility. When the aging temperature was 250°C~400°C, ω precipitation or β’ phase separation occurred from β matrix, and finally transformed to α precipitates. The tensile strength increased firstly and then decreased with increasing aging time. When aged at above 400°C, α phase precipitated fast from the alloy, and the strength increased gradually.

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.

Influence of Rate of Heating to Aging Temperature on Precipitation Hardening in a Metastable β Titanium Alloy

2014 ◽  
Vol 1025-1026 ◽  
pp. 445-450 ◽  
Author(s):  
Ashwary Pande ◽  
Salil Sainis ◽  
Santhosh Rajaraman ◽  
Geetha Manivasagam ◽  
M. Nageswara Rao
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Heating Rate ◽  
Aging Temperature ◽  
Alpha Phase ◽  
Slow Heating ◽  
Precipitation Reaction ◽  
Heating Rates ◽  
Rate Of Heating ◽  
Reduction In Area

A comparison between slow heating to aging temperature and direct charging at aging temperature on the microstructure and mechanical properties obtained after the aging was established for the metastable beta (β) titanium alloy Ti-15V-3Cr-3Al-3Sn. The alloy was subjected to two single aging (SA) and two duplex aging (DA) conditions, with two heating rates to aging temperature: (i) low heating rate of 5 oC/min (ii) direct charging into a furnace heated to aging temperature. The microstructure analysis was carried out using Field Emission Scanning Electron Microscopy. Mechanical Testing was carried to evaluate Ultimate Tensile Strength (UTS), 0.2% Yield Strength (YS), % Elongation (%El.), % Reduction in area (%RA) and hardness. In the case of SA samples aged at 500 °C for 8 h and 500 °C for 10 h, heating rate of 5 °C/min to aging temperature resulted in a finer microstructure but did not help in achieving better strength-ductility combination compared to direct charging. Lower rate of heating allows enough dwell time in the temperature range 250-300 oC for pre-precipitation reaction to occur which aids in fine scale precipitation of alpha phase during aging. In the case of DA samples aged at 250 oC for 24 h followed by 500 oC for 8 h and 300 oC for 10 h followed by 500 oC for 10 h, no tangible difference between lower rate of heating and direct charging was observed in mechanical properties or microstructure. This is believed to be due to the pre-aging steps 250 oC/24 h or 300 oC/10h in the two DA treatments, which create finely distributed precursors thereby leaving no scope for the heating rate to play a role.

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.

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.

Orientation relationship between α-phase and high-pressure ω-phase of pure group IV transition metals

2015 ◽  
Vol 98 ◽  
pp. 1-4 ◽  
Author(s):  
Nozomu Adachi ◽  
Yoshikazu Todaka ◽  
Hiroshi Suzuki ◽  
Minoru Umemoto
Keyword(s):  
High Pressure ◽  
Transition Metals ◽  
Orientation Relationship ◽  
Group Iv ◽  
Ω Phase ◽  
Α Phase

scholarly journals Influence of Microstructures on Tensile Properties at 400℃ of TC4 Titanium Alloy

2020 ◽  
Vol 321 ◽  
pp. 11048
Author(s):  
Ren Yong ◽  
Yang Nan ◽  
Lei Jinwen ◽  
Li Shaoqiang ◽  
Du Yuxuan
Keyword(s):  
Titanium Alloy ◽  
Yield Strength ◽  
Tensile Properties ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Air Cooling ◽  
Phase Volume Fraction ◽  
Tc4 Titanium Alloy ◽  
Α Phase ◽  
Cooling Speed

The effects of primary α phase volume fraction on the tensile properties at 400℃ of TC4 titanium alloy was studied by different solution temperature(Tβ-(10~80)℃). The effects of the thick of secondary α phase on the tensile properties at 400℃ of TC4 titanium alloy was studied by different cooling speed after solution treatment (water quench, air cooling, furnace cooling). The results show that with the decrease of primary α phase, the tensile and yield strength increase up, but the ductility has a little change. The thick of secondary α phase increases with the deceases of cooling speed after solution treatment, highest tensile and yield strength by water quench, the tensile strength of air cooling and furnace cooling were basically the same, but the yield strength of furnace cooling was 40MPa lower than air cooling. Therefore, the influence of the primary α phase volume fraction on the tensile strength at 400℃ was particularly obvious, we can control solution treatment and cooling way in combination with different requirements.

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