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 ◽  
...  

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.

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 625
Author(s):  
Yoko Yamabe-Mitarai ◽  
Syuji Kuroda ◽  
Norie Motohashi ◽  
Takanobu Hiroto ◽  
Akira Ishida ◽  
...  

The Ti compressor disks of aviation jet engines are produced by forging. Their microstructure, which depends on the forging conditions, strongly affects their mechanical properties. In this study, changes in the microstructure of Ti-17 alloy as a result of different solution-treatment (ST) temperatures and the related tensile yield strengths were investigated to elucidate the correlation between the ST temperature, microstructure, and yield strength. Ti-17 alloys ingots were isothermally forged at 800 °C and solution-treated at 750, 800, and 850 °C. The microstructure and yield strength were investigated for samples subjected to different ST temperatures. The primary α phase formed during the ST, and the secondary α phase formed during the aging treatment at 620 °C. The yield strength increased with increasing volume fraction of the primary α phase and increased further upon formation of the secondary α phase during the tensile test at room temperature. The correlation of the primary and secondary α phases with yield strength was clarified for tensile properties at room temperature, 450, and 600 °C. An equation to predict the yield strength was constructed using the volume fraction of the primary and secondary α phases.


2014 ◽  
Vol 1002 ◽  
pp. 73-76 ◽  
Author(s):  
Xia Ding ◽  
Xiao Li Wang ◽  
Cong Hui Si ◽  
Li Na Zhao ◽  
Kai Hong Ding ◽  
...  

In order to increase the intrinsic coercivity of the Nd-Fe-B magnets, the aging process optimization had been carried out. The results showed that more than 17 kOe intrinsic coercivity could be obtained by the aging process optimization. The microstructures and the fractures of the Nd-Fe-B magnets treated by the optimized aging process were also investigated by optical microscope, thermal field emission scanning electron microscopy and energy disperse spectroscopy. It was showed that the thin, continuous and smooth Nd-rich layer along the boundaries of the main crystal phase Nd2Fe14B could be formed by the optimized aging treatment and it resulted in the increase of the intrinsic coercivity of the Nd-Fe-B magnets.


2020 ◽  
Vol 321 ◽  
pp. 11048
Author(s):  
Ren Yong ◽  
Yang Nan ◽  
Lei Jinwen ◽  
Li Shaoqiang ◽  
Du Yuxuan

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.


2011 ◽  
Vol 217-218 ◽  
pp. 1277-1282
Author(s):  
Rong Tan Huang ◽  
Wen Han Chen ◽  
Lv Wen Tsay

Ti-15V-3Cr-3Al-3Sn, β-phase titanium alloy, is subjected to study the temperature effects on microstructure and mechanical behavior by using different aging temperature (426 ∼ 600 oC) and high temperature (450oC) notched tensile test. It follows that the highest hardness of Ti-15V-3Cr-3Al-3Sn would be got up to 420 Hv after 426 oC aging. Afterward, the hardness is decreasing with increasing aging temperature. By means of microstructure analyses, it reveals that the narrow and intragranular α-phase precipitates with lamella-shape in the grains at 426 oC aging treatment caused the age hardening of the titanium alloy. Subsequently, the α-phase precipitates were coarsening with increasing the aging temperature and showed the thick morphologies distributed along grain boundaries, which results in overaging. In the notched tensile test at 450oC, the highest notched tensile strength (1160 MPa) is also obtained after 426oC aging treatment, and then decreasing with increasing aging temperature. Its mechanical behavior is different from the room temperature notched tensile test, which demonstrates the lowest notched tensile strength (813 MPa) after 426 oC aging treatment due to the notched embrittlement effect. According to microstructure study, it suggests that the environment temperature effect enhanced the toughness of the alloy and terminated the notched embrittlement effect resulted from the 426oC aging treatment.


2014 ◽  
Vol 783-786 ◽  
pp. 2423-2428 ◽  
Author(s):  
Hideki Hosoda ◽  
Kenta Kasuya ◽  
Masaki Tahara ◽  
Tomonari Inamura ◽  
Shuichi Miyazaki

In order to develop new β (bcc) Ti alloys, the Ti-Fe-Sn system was focused and phase constitution, microstructure, mechanical properties of Ti-5mol%Fe-6mol%Sn and Ti-6mol%Fe-3mol%Sn were clarified in addition to aging effect. It was estimated by differential scanning calorimetry (DSC) that α phase is formed at temperature from 773-779K and that β transus temperature is 1019K in both the alloys. X-ray diffraction analysis revealed that, in both alloys, β single phase is formed after the solution treatment (ST) at 1273K followed by water quenching, while α phase is formed after the aging at 773K and 873K for 3.6ks. The formation of α phase is also confirmed by optical microscopy. The volume fraction of α phase reaches to 90% in Ti-5Fe-6Sn and 80% in Ti-6Fe-3Sn after the aging at 873K for 3.6ks. The 0.2% proof stress was increased by aging at 873K from 550MPa to 650MPa in Ti-5Fe-6Sn and 500MPa to 690MPa in Ti-6Fe-3Sn. Besides, apparent Young’s modulus measured by dynamic mechanical analysis was raised by the aging treatment. These changes in the mechanical properties were discussed in connection with α phase precipitation.


Author(s):  
Hosam Alegaly Alaraby ◽  
Magdi Mohamad A Lswalhia ◽  
Tajammul Ahmed

<p class="abstract"><strong>Background:</strong> Titanium and its alloys are being extensively researched and are applied relatively in different fields of dentistry since 1970s. Its inherent advantages like high strength, ductility, low modulus of elasticity, ease of formation of oxidized surface layer, ability to retain mechanical integrity after autoclave and relatively low toxicity has led to extensive application of titanium and its alloys in implant dentistry.</p><p class="abstract"><strong>Methods:</strong> The Titanium alloy Ti-6Al-4V dental implant material used for the present study was procured from Mishra Dhatu Nigam (Midhani, Hyderabad). The mechanically polished samples were etched using Kroll’s reagent (5% hydrofluoric acid+10% nitric acid+85% water). The etched specimens were examined under optical microscope.  </p><p class="abstract"><strong>Results:</strong> The primary α phase being the low temperature phase, is stable and shows single phase microstructure. The size and volume fraction of the primary α and transformed β phases depend on the solution treatment temperatures and the subsequent rate of cooling.</p><p><strong>Conclusions:</strong> The success of the treatment modality relies on the knowledge of the properties required to employ them at the right situation. </p>


2020 ◽  
Vol 12 (9) ◽  
pp. 1399-1402
Author(s):  
Ji-Hyun Kim ◽  
Min-Su Kim ◽  
Tae-Hyun Nam

Ti–xNi–12Cu (at%) (x = 39, 40) alloys were prepared and then their transformation behavior and microstructures were investigated after solution treatment at various temperatures by means of scanning electron microscopy, energy dispersive X-ray spectroscopy, and differential scanning calorimetry. Matrix (B2), Ti2 (Ni, Cu) and Ti(Ni, Cu)2 phases were observed in all specimens except the TiNi39Cu12 alloy solution treated at 1373 K in which matrix (B2) and Ti2 (Ni, Cu) were observed. Volume fraction of Ti(Ni, Cu)2 phase decreased with increasing solution treatment temperature. All specimens showed the B2–B19 martensitic transformation behavior. Transformation temperatures and hysteresis decreased with increasing solution treatment temperature, which was ascribed to the decrease in the volume fraction of Ti(Ni, Cu)2 phase resulting in the increase in Ni content of matrix.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2776
Author(s):  
Xiqin Mao ◽  
Meigui Ou ◽  
Desong Chen ◽  
Ming Yang ◽  
Wei Long

Two-phase TC21 titanium alloy samples were solution-treated at 990 °C (β phase zone) and cooled by furnace cooling (FC), air cooling (AC), and water quenching (WQ), respectively. The second solution stage treatment was carried out at 900 °C (α + β phase zone), then aging treatment was performed at 590 °C. The influence of the size and quantity of the α phase on the properties of the sample were studied. The experimental results showed as the cooling rate increased after the first solution stage treatment, wherein the thickness of primary layer α gradually decreased, and the tensile strength and yield strength gradually increased. After the second solution stage treatment, the tensile properties of samples increased due to the quantity of layers α increased. The aging treatment promoted the precipitation of the dispersed α phase and further improved the tensile strength. After the third solution stage treatments, the FC samples with more β-phase had the best comprehensive mechanical properties.


2017 ◽  
Vol 898 ◽  
pp. 766-771 ◽  
Author(s):  
Yi Fan Feng ◽  
Ren Bo Song ◽  
Shi Guang Peng ◽  
Chang Hong Cai ◽  
Zhi Dong Tan

The effect of aging temperature on microstructure and mechanical properties of Fe-16Mn-1.3C-0.3V steel was investigated. After a series of heat treatment experimental processes, including solution treatment at 1080 oC for 1 h then aging treatment at 350 oC, 400 oC, 450 oC, 500 oC and 550 oC for 1 h respectively, the microstructure of V alloyed high manganese austenitic steels were studied using optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The experimental steel had the best comprehensive performance after aging treated at 450 oC for 1 h. It presented hardness of 249HB, impact toughness of 215 J·cm-2, tensile strength of 707 MPa, yield strength of 421 MPa and elongation of 30.8%. With the aging temperature increased, the amount of precipitates increased and precipitates gradually transformed from globularity to needle. EDS analysis showed the most striking difference between two types carbides. That the globular carbide had a lot of vanadium element, which could cause the hardness of globular carbide higher than needle-like carbide. TEM showed the size of these globular carbide particles were 10~100 nm. SADP demonstrated that the fine globular precipitate was vanadium carbide (VC).


2011 ◽  
Vol 287-290 ◽  
pp. 868-874 ◽  
Author(s):  
Si Guo Mu ◽  
Jiao Yan Dai ◽  
Yong Ru Wang ◽  
Guo Hui Chao ◽  
Xi Ping Hong ◽  
...  

The microstructure of Cu-37%Zn-2%Mn-1.6%Al-0.7%Fe-0.7%Si (mass fraction)alloy was studied by scan electron microscopy, X-ray and optical microscopy. The α phase ratio and micro-hardness of this alloy after aging treatment were investigated. The results show that three kinds of phases, such as α phase, β phase and hexagonal club-shape Mn5Si3 phase were observed. The needle α phase ratio increases with aging temperature under 420°C and reach peak value 25 percent after aging at 420°C×1h. The α phase ratio begin decreases when the aging temperature over 420°C. The micro-hardness varying with aging temperature is the opposite.


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