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.

scholarly journals Effects of Heat Treatment Temperature on Microstructure and Mechanical Properties of M2 High-Speed Steel Selective Laser Melting Samples

2020 ◽  
Author(s):  
Huan Ding ◽  
Xiong Xiang ◽  
Rutie Liu ◽  
Jie Xu
Keyword(s):  
Heat Treatment ◽  
Flexural Strength ◽  
Selective Laser Melting ◽  
Heat Treatment Temperature ◽  
High Speed ◽  
High Speed Steel ◽  
Treatment Temperature ◽  
Laser Melting ◽  
Average Value ◽  
M2 High Speed Steel

At different heat treatment temperatures, the hardness and flexural strength of M2 high-speed steel selective laser melting (SLM) parts show mixed trends. When the heat treatment temperature is 260°C, the hardness and flexural strength of the M2 high-speed steel SLM part are decreased, but the hardness difference between the upper and lower surfaces of the M2 high-speed steel SLM part is also reduced. When the heat treatment temperature is 560°C, the hardness and flexural strength of the M2 high-speed steel SLM part are almost close to that of the original M2 high-speed steel SLM part, and the performance gradient in the sample is improved, and the overall structure is uniform. When the subsequent heat treatment temperature is 860 °C, the hardness of the SLM parts reaches a minimum, with an average value of 24 HRC. However, the flexural strength exceeds that of the original SLM parts. Moreover, the microstructure of the sample is uniform, which significantly improves the anisotropy of performance.

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.

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.

Study on the Transformation of (α+β) Phase to β Phase in Deformed Ti-6Al-4V Alloy during the Heat Treatment

2012 ◽  
Vol 454 ◽  
pp. 97-100
Author(s):  
Lu Ning Zhang ◽  
Hai Qiang Zhao ◽  
Li Yuan Sheng ◽  
Lan Zhang Zhou
Keyword(s):  
Heat Treatment ◽  
Hot Rolling ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Β Phase ◽  
Α Phase ◽  
Heat Treated

In the present paper the Ti-6Al-4V alloy with α and β phases was deformed by hot rolling and solution heat treated at different temperature for 30 minutes to investigate the transformation of (α+β) to β. The results show that the deformed alloy possesses the typical (α+β) dual-phases microstructure, when the alloy is treated below the 950 °C. With the increase of the heat treatment temperature the volume of α phase decreases significantly. When the temperature is higher than the 970 °C, almost no α phase is left in the alloy.

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

Microstructure and Mechanical Properties of Ti-6Al-4V Alloy Samples Fabricated by Selective Laser Melting

2018 ◽  
Vol 770 ◽  
pp. 179-186 ◽  
Author(s):  
Jing Bo Gao ◽  
Xiao Li Zhao ◽  
Ju Kun Yue ◽  
Meng Chao Qi ◽  
De Liang Zhang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Crystal Growth ◽  
Yield Strength ◽  
Selective Laser Melting ◽  
Lamellar Structure ◽  
Growth Direction ◽  
Laser Melting ◽  
Α Phase ◽  
Dog Bone

Ti-6Al-4V (wt%) alloy samples with dog-bone and box shapes respectively were fabricated by selective laser melting (SLM). The microstructures and mechanical properties of the 3D printed Ti-6Al-4V samples with and without heat treatment were characterized and tested. The microstructures of the as-fabricated dog-bone shaped samples were mainly composed of acicular α’ phase. After annealing at 700°C, the acicular α’ phase changed into an α/β lamellar structure. After solution treatment at 955°C, water quenching and aging at 550°C, the microstructure was mainly composed of primary α phase and α/β lamellar structure. The optimum heat treatment is annealing, and the mechanical properties of the annealed sample are as follows: yield strength: 1015 MPa, ultimate tensile strength (UTS): 1083 MPa and elongation to fracture: 7.9%. The microstructures of the box-shaped samples after annealing mainly consist of α phase and α/β lamellar structure. When stretched along the direction parallel to the crystal growth direction, the yield strength and UTS of the sample are 1054 and 1090 MPa，and its elongation to fracture is 6.3%. When stretched along the direction perpendicular to the crystal growth direction, the yield strength and UTS of the sample are 1019 and 1068 MPa respectively, and its elongation to fracture is 8.7%.

scholarly journals Effect of the Distance from Build Platform and Post-Heat Treatment of AlSi10Mg Alloy Manufactured by Single- and Multi-Laser Selective Laser Melting

2021 ◽  
Author(s):  
Emanuela Cerri ◽  
Emanuele Ghio ◽  
Giovanni Bolelli
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Vickers Microhardness ◽  
Treatment Temperature ◽  
Progressive Decrease ◽  
Laser Melting ◽  
Post Heat Treatment ◽  
Working Temperature ◽  
Eutectic Si ◽  
Higher Temperature

AbstractIn the present study, AlSi10Mg samples produced by selective laser melting (SLM) were studied. Samples were machined from two types of bars obtained through different methods: either single laser (SL) or multiple laser (ML) machine setup. The bars were built perpendicular to the platform, which was pre-heated at 150 °C (working temperature), up to a height of 300 mm. The effect of the distance from the platform on the mechanical properties was investigated through tensile samples in as-built condition and after unconventional heat treatments (U-HT). Tensile strength changed by 80 MPa along the Z-axis (build direction) for SL case and by 100 MPa for ML case in the as-built samples. Vickers microhardness revealed an analogous gradient. This was correlated to a gradient in intra-granular precipitates' distribution along the Z-axis, as revealed by scanning electron microscopy (SEM). An unconventional heat treatment at 175 °C for 6h slightly improves the mechanical strength; higher temperature treatments at 200 and 225 °C for the same duration cause a progressive decrease in strength with an increase in elongation. The amount and size of the precipitates and the thickness of eutectic Si change with the heat treatment temperature, justifying the mechanical behavior.

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.

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