scholarly journals The Influence of Heat Treatment Temperature on Microstructures and Mechanical Properties of Titanium Alloy Fabricated by Laser Melting Deposition

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4087 ◽  
Author(s):  
Wei Wang ◽  
Xiaowen Xu ◽  
Ruixin Ma ◽  
Guojian Xu ◽  
Weijun Liu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
Testing Machine ◽  
Optical Microscope ◽  
Treatment Temperature ◽  
Air Cooling ◽  
Laser Melting ◽  
Tc4 Titanium Alloy ◽  
Β Phase ◽  
Laser Melting Deposition

Ti-6Al-4V (TC4) titanium alloy parts were successfully fabricated by laser melting deposition (LMD) technology in this study. Proper normalizing temperatures were presented in detailed for bulk LMD specimens. Optical microscope, scanning electron microscopy, X-ray diffraction, and electronic universal testing machine were used to characterize the microstructures, phase compositions, the tensile properties and hardness of the TC4 alloy parts treated using different normalizing temperature. The experimental results showed that the as-fabricated LMD specimens’ microstructures mainly consisted of α-Ti phase with a small amount of β-Ti phase. After normalizing treatment, in the area of α-Ti phase, the recrystallized length and width of α-Ti phase both increased. When normalizing in the (α + β) phase field, the elongated primary α-Ti phase in the as-deposited state was truncated due to the precipitation of β-Ti phase and became a short rod-like primary α-Ti phase. In as-fabricated microstructure, the β-Ti phase was precipitated between different short rod-shaped α-Ti phases distributed as basketweave. After normalizing treatment at 990 for two hours with subsequent air cooling, the TC4 titanium alloy had significant different microstructures from original sample produced by LMD. The normalizing treatment methods and temperature can be qualified as a prospective heat treatment of titanium alloy fabricating by laser melting deposition.

scholarly journals The Influence of Heat Treatment Temperature on Microstructures and Mechanical Properties of Titanium Alloy Fabricated by Laser Melting Deposition

2020 ◽  
Author(s):  
Wei Wang ◽  
Xiaowen Xu ◽  
Ruixin Ma ◽  
Guojian Xu ◽  
Weijun Liu
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
Testing Machine ◽  
Beta Phase ◽  
Optical Microscope ◽  
Treatment Temperature ◽  
Air Cooling ◽  
Laser Melting ◽  
Tc4 Titanium Alloy ◽  
Laser Melting Deposition

Ti-6Al-4V (TC4) titanium alloy parts were successfully fabricated by laser melting deposition (LMD)technology in this study. Proper normalizing temperatures were presented in detailed for bulk LMD specimens. Optical microscope, scanning electron microscopy, X-ray diffraction and electronic universal testing machine were used to characterize the microstructures, phase compositions, the tensile properties and hardness of the TC4 alloy parts treated using different normalizing temperature. The experimental results showed that the as-fabricated LMD speceimens microstructures mainly consisted of α-Ti phase with a small amount of β-Ti phase. After normalizing treatment, in the area of α-Ti phase, the recrystallized length and width of α-Ti phase both increased. When normalizing in the (α+β) phase field, the elongated primary α-Ti phase in the as-deposited state was truncated due to the precipitation of β-Ti phase and became a short rod-like primary α-Ti phase. In as-fabricated microstructure, the β-Ti phase was precipitated between different short rod-shaped α-Ti phases distributed as basketweave. After normalizing treatment at 990 for two hours with subsequent air cooling, the TC4 titanium alloy had significant different microstructures from original sample produced by LMD. Moreover, the mismatch of tensile and hardness property was mitigated in this heat treatment. So the normalizing treatment methods and temperature can be qualified as a prospective heat treatment of titanium alloy fabricating by laser melting deposition.

scholarly journals The Heat Treatment Influence on the Microstructure and Hardness of TC4 Titanium Alloy Manufactured via Selective Laser Melting

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1318 ◽  
Author(s):  
Zhan-Yong Zhao ◽  
Liang Li ◽  
Pei-Kang Bai ◽  
Yang Jin ◽  
Li-Yun Wu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
Critical Temperature ◽  
Selective Laser Melting ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Laser Melting ◽  
Β Phase ◽  
Α Phase ◽  
Increasing Temperature

In this research, the effect of several heat treatments on the microstructure and microhardness of TC4 (Ti6Al4V) titanium alloy processed by selective laser melting (SLM) is studied. The results showed that the original acicular martensite α′-phase in the TC4 alloy formed by SLM is converted into a lamellar mixture of α + β for heat treatment temperatures below the critical temperature (T0 at approximately 893 °C). With the increase of heat treatment temperature, the size of the lamellar mixture structure inside of the TC4 part gradually grows. When the heat treatment temperature is above T0, because the cooling rate is relatively steep, the β-phase recrystallization transforms into a compact secondary α-phase, and a basketweave structure can be found because the primary α-phase develop and connect or cross each other with different orientations. The residence time for TC4 SLM parts when the treatment temperature is below the critical temperature has little influence: both the α-phase and the β-phase will tend to coarsen but hinder each other, thereby limiting grain growth. The microhardness gradually decreases with increasing temperature when the TC4 SLM part is treated below the critical temperature. Conversely, the microhardness increases significantly with increasing temperature when the TC4 SLM part is treated above the critical temperature.

Effect of Heat Treatment on the Microstructure Evolution of Ti-6Al-3Sn-3Zr-3Mo-3Nb-1W-0.2Si Titanium Alloy

2016 ◽  
Vol 879 ◽  
pp. 1828-1833 ◽  
Author(s):  
Xiao Yun Song ◽  
Wen Jing Zhang ◽  
Teng Ma ◽  
Wen Jun Ye ◽  
Song Xiao Hui
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
Microstructure Evolution ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
Water Quenching ◽  
Air Cooling ◽  
Two Phase ◽  
Β Phase ◽  
Α Phase

Ti-6Al-3Sn-3Zr-3Mo-3Nb-1W-0.2Si (BTi-6431S) alloy is a novel two-phase high temperature titanium alloy for short-term using in aerospace industry up to 700°C. The effects of heat treatment on the microstructure evolution of BTi-6431S alloy bar were investigated through optical microscopy (OM), X-ray diffraction (XRD), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). The results show that solution treatment in β region at 1010°C followed by water quenching results in the formation of orthorhombic martensite α′′ phase, while air cooling leads to the formation of hexagonal martensite α′ phase. When solution-treated in α+β phase field at temperatures from 900°C to 980°C following by water quenching, the content of primary α phase decreases with the increase of heat treatment temperature. For the alloy subjected to identical heat treatment, the content of Al in α phase is much higher than that in β phase, while the contents of Nb, Mo and W elements in α phase are much less than those in β phase.

Microstructure and Mechanical Properties of TC4 Titanium Alloy Formed by Selective Laser Melting After Heat Treatment

2017 ◽  
Vol 44 (9) ◽  
pp. 0902001
Author(s):  
肖振楠 Xiao Zhennan ◽  
刘婷婷 Liu Tingting ◽  
廖文和 Liao Wenhe ◽  
张长东 Zhang Changdong ◽  
杨涛 Yang Tao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Titanium Alloy ◽  
Selective Laser Melting ◽  
Laser Melting ◽  
Tc4 Titanium Alloy ◽  
Microstructure And Mechanical Properties

Assessment of Mechanical Properties and Transformation Behavior of Locally-Made Ni-Ti Alloys Used in Orthodontics

2008 ◽  
Vol 55-57 ◽  
pp. 245-248 ◽  
Author(s):  
Nattiree Chiranavanit ◽  
Anak Khantachawana ◽  
N. Anuwongnukroh ◽  
Surachai Dechkunakorn
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Testing Machine ◽  
Optical Microscope ◽  
Treatment Temperature ◽  
Bending Test ◽  
Hardness Tester ◽  
Ti Alloys ◽  
Heat Treated ◽  
Average Grain Size

Ni-Ti alloy wires have been widely used in clinical orthodontics because of their properties of superelasticity (SE) and shape memory effect (SME). The purpose of this study was to assess the mechanical properties and phase transformation of 50.7Ni-49.3 Ti (at%) alloy (NT) and 45.2Ni-49.8Ti-5.0Cu (at%) alloy (NTC), cold-rolled with various percent reductions. To investigate SE and SME, heat-treatment was performed at 400°C and 600°C for 1 h. The specimens were examined using an Energy-Dispersive X-ray Spectroscope (EDS), Differential Scanning Calorimeter (DSC), Universal Testing Machine (Instron), Vickers Hardness Tester and Optical Microscope (OM). On the three-point bending test, the superelastic load-deflection curve was seen in NTC heat-treated at 400°C. Furthermore, NT heat-treated at 400°C with 30% reduction produced a partial superelastic curve. For SME, no conditions revealed superelasticity at the oral temperature. Micro-hardness value increased with greater percentage reduction. The average grain size for all specimens was typically 55-80 µm. The results showed that locally-made Ni-Ti alloys have various transformation behaviors and mechanical properties depending on three principal factors: chemical composition, work-hardening (the percent reduction) and heat-treatment temperature.

Investigation of the Laser Melting Deposited TiAl Intermetallic Alloy on Titanium Alloy

2010 ◽  
Vol 146-147 ◽  
pp. 1638-1641
Author(s):  
Yuan Bin Zhang ◽  
Huai Xue Li ◽  
Kai Zhang
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Energy Dispersive Spectrometer ◽  
Testing Machine ◽  
Frictional Coefficient ◽  
Optical Microscope ◽  
Wear Testing ◽  
Laser Melting ◽  
Hardness Tester ◽  
Tial Layer

To improve the wear resistance of Titanium alloy, TiAl intermetallic claddings were fabricated on TC4 substrate using laser melting deposition technology. Optical microscope, scan electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction meter were applied to investigate the deposited TiAl layer and their interface with substrate. Using hardness tester and M-2000 wear testing machine, hardness, frictional coefficient and wear resistance of the TiAl layers and TC4 alloy were tested. It was indicated that the deposited TiAl layers were well integrated with TC4 substrate, γ-TiAl and Ti3Al dual phase microstructure was formed in the deposited layer. With higher hardness and lower friction coefficient, the deposited TiAl layer improved the wear resistance obviously comparing to TC4 titanium alloy substrate.

Microstructures and Properties of Ti-Nb Alloys Produced by Powder Metallurgy

2011 ◽  
Vol 80-81 ◽  
pp. 431-435 ◽  
Author(s):  
Zheng Cun Zhou ◽  
J. Du ◽  
H. Yang ◽  
S.Y. Gu ◽  
Y.J. Yan
Keyword(s):  
Powder Metallurgy ◽  
Testing Machine ◽  
Optical Microscope ◽  
Mechanical Analysis ◽  
Sintered Alloy ◽  
Xrd Diffraction ◽  
Β Phase ◽  
Ω Phase ◽  
Nb Content ◽  
And Storage

Ti-Nb alloys were prepared by powder metallurgy. Their microstructures are detected by the XRD diffraction and are observed using an optical microscope. The mechanical properties are tested using a dynamic mechanical analysis (DMA) Q800 from TA Instruments in single cantilever mode and using a 100 KN MTS testing machine with control software. It has been found that the sintered Ti-Nb alloys possess the stable α and β phases and the amount in β phase increases with increasing Nb content. The water quenched Ti-35.4Nb alloy contains α,,and βM. The as-sintered alloy has higher yield stress and storage modulus than the water quenched Ti-35.4Nb alloy, which is resulted from the α phase with high modulus in the as-sintered alloy. The ω phase can be precipitated from βMwhen the water quenched Ti-35.4Nb alloy is aged at 300 °C, causing the modulus to increase since ω phase has large modulus.

scholarly journals Significantly fast spinodal decomposition and inhomogeneous nanoscale martensitic transformation in Ti–Nb–O alloys

2020 ◽  
Vol 321 ◽  
pp. 11049
Author(s):  
Yuya ISHIGURO ◽  
Yuhki TSUKADA ◽  
Toshiyuki KOYAMA
Keyword(s):  
Heat Treatment ◽  
Martensitic Transformation ◽  
Spinodal Decomposition ◽  
Treatment Temperature ◽  
Phase Field Method ◽  
Isothermal Heat Treatment ◽  
Phase Decomposition ◽  
Rate Condition ◽  
Continuous Cooling ◽  
Β Phase

The β phase spinodal decomposition during continuous cooling in Ti‒Nb‒O alloys is investigated by the phase-field method. Addition of only a few at.%O to Ti‒23Nb (at.%) alloy remarkably increases the driving force of the β phase spinodal decomposition. During isothermal heat treatment at 1000 K and 1100 K in Ti‒23Nb‒3O (at.%) alloy, the β phase separates into β1 phase denoted as (Ti)1(O, Va)3 and β2 phase denoted as (Ti, Nb)1(Va)3, resulting in the formation of nanoscale concentration modulation. The phase decomposition progresses in 0.3‒20 ms. In Ti‒23Nb‒XO alloys (X = 1.0, 1.2, 2.0), the spinodal decomposition occurs during continuous cooling with the rate of 500 K s‒1, indicating that the spinodal decomposition occurs during water quenching in the alloys. It is assumed that there is a threshold value of oxygen composition for inducing the spinodal decomposition because it does not occur during continuous cooling in Ti‒23Nb‒0.6O (at.%) alloy. The concentration modulation introduced by the β phase decomposition has significant effect on the β→α” martensitic transformation. Hence, it seems that for controlling microstructure and mechanical properties of Ti‒Nb‒O alloys, careful control of heat treatment temperature and cooling rate condition is required.

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

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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