Microstructure and defect of titanium alloy electron beam deep penetration welded joint

2012 ◽  
Vol 22 (11) ◽  
pp. 2633-2637 ◽  
Author(s):  
Bing-gang ZHANG ◽  
Ming-xiao SHI ◽  
Guo-qing CHEN ◽  
Ji-cai FENG
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
Welded Joint ◽  
Deep Penetration

Influence of Hydrogen on Microstructure of Electron Beam Welded Joint

2013 ◽  
Vol 753-755 ◽  
pp. 367-371
Author(s):  
Xin Liu ◽  
Zhi Yong Mao
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
Weld Metal ◽  
Hydrogen Content ◽  
Welded Joints ◽  
Welded Joint ◽  
Optical Microscope ◽  
Hydrogen Charging ◽  
Tc4 Titanium Alloy ◽  
Oxygen Analyzer

Hydrogen distributions of TC4 electron beam welded joints with different hydrogen contents were measured by hydrogen oxygen analyzer. Microstructures of electron beam welded joints for TC4 titanium alloy with different hydrogen contents were observed and analyzed by optical microscope and TEM. And the influence of hydrogen on microstructure of the joints was investigated. The results show that the hydrogen content of weld HAZ is higher than other zones in the electron beam welded joints, while the hydrogen content of fusion zone is lower than other zones in the electron beam welded joints. The microstructure of the weld metal is fine lamellar α + β phase after hydrogen charging. In the range of hydrogen contents discussed in this study (from 0 to 0.101 wt. %), with the increase of hydrogen content, there is little change in the appearance of the microstructure of the weld metal. There are stacking fault and dislocation in the microstructure of TC4 electron beam welded joints with different hydrogen contents after hydrogen charging. The presence of hydrogen can promote the formation of twins in electron beam welded joints. With the increase of hydrogen content, the number of twins is increased.

Effect of Hydrogen on Microstructure of TA15 Electron Beam Welded Joint

2011 ◽  
Vol 287-290 ◽  
pp. 2393-2396 ◽  
Author(s):  
Xin Liu ◽  
Zhi Yong Mao ◽  
Yong Ping Lei
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
Weld Metal ◽  
Hydrogen Content ◽  
Welded Joints ◽  
Welded Joint ◽  
Hydrogen Charging ◽  
Β Phase ◽  
Ta15 Titanium Alloy ◽  
Certainty Level

Microstructures of electron beam welded joints for TA15 titanium alloy with different hydrogen contents were observed and analyzed by SEM and TEM. And the influence of hydrogen on microstructure of the joints was investigated. The results show that the microstructure of the weld metal is lamellar α+β phase after hydrogen charging. In the range of hydrogen contents discussed in this study (from 0 to 0.101 wt%), With the increase of hydrogen content, there is little change in the appearance of the microstructure of the weld metal. The presence of hydrogen can promote the growth of twins in electron beam welded joints. With the increase of hydrogen content, the number of twins is increased. When hydrogen content reaches to a certainty level, hydrides are found in TA15 electron beam welded joints.

scholarly journals Influence of Welded Pores on Very Long-Life Fatigue Failure of the Electron Beam Welding Joint of TC17 Titanium Alloy

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1825 ◽  
Author(s):  
Fulin Liu ◽  
Hong Zhang ◽  
Hanqing Liu ◽  
Yao Chen ◽  
Khan Muhammad Kashif ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
Fatigue Life ◽  
Base Metal ◽  
Fatigue Failure ◽  
Electron Beam Welding ◽  
Welded Joint ◽  
Fatigue Cracks ◽  
Failure Behavior ◽  
Long Life

The electron beam welding process is widely used in the connection among titanium alloy material parts of aero-engines. Its mechanical properties need to meet the requirements of long life and high reliability. In this paper, the static strength and the fatigue failure behavior of the electron beam weldments of TC17 titanium alloy were investigated experimentally under low amplitude high frequency (20 kHz), and the mechanical response and failure mechanism under different external loading conditions were analyzed. In summary, the samples were found to have anisotropic microstructure. The tensile strength of the PWHT of TC17 EBW joint was ~4.5% lower than that of the base metal. Meanwhile, compared with the base metal, the fatigue strength was reduced by 45.5% at 109 cycles of fatigue life. The fracture analysis showed that the fatigue failure of the welded joint of TC17 alloy was caused by the welded pores and the fatigue cracks initiated from the welded pores. A fine granular area (FGA) was observed around the crack initiation region. The existence of pores caused the stress intensity factor of the fine granular area (KFGA) to be inversely proportional to the fatigue life. The KFGA calculation formula was modified and the fatigue crack propagation threshold of the welded joint of TC17 alloy was calculated (3.62 MPa·m1/2). Moreover, the influences of the effective size and the relative depth of the pores on the very long fatigue life of the electron beam welded joint of TC17 titanium alloy were discussed.

Linear Friction and Electron Beam Welded Joints of Ti2AlNb/TC11

2010 ◽  
Vol 97-101 ◽  
pp. 3895-3898 ◽  
Author(s):  
Li Jun Tan ◽  
Ze Kun Yao ◽  
Chun Qin ◽  
Hong Zhen Guo ◽  
Shi Qiong Li
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
Welded Joints ◽  
Welded Joint ◽  
Aerospace Industry ◽  
Friction Process ◽  
Dissimilar Joining ◽  
Linear Friction ◽  
Technical Interest ◽  
O Phase

Dissimilar joining of Ti-22Al-25Nb alloy and an α+β titanium alloy TC11 were carried out using electron beam process and linear friction process, respectively. The microstructure and tensile properties of the joints were investigated. The results show that both EBW and LFW could be adopted to the dissimilar joining of Ti-22Al-25Nb/TC11. The EB welded joint exhibits higher strength than that of the LF welded joint, due to the precipitation of O phase in the fusion zone of the former one. These results can be expected to be of great technical interest as basic data for the use of EBW or LFW in aerospace industry.

Thermal efficiency in electron beam processing of structural materials

Vestnik MEI ◽  
2020 ◽  
Vol 6 (6) ◽  
pp. 60-66
Author(s):  
Egor V. Terent'ev ◽  
◽  
Viktor K. Dragunov ◽  
Andrey P. Sliva ◽  
Aleksey L. Goncharov ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
Thermal Diffusivity ◽  
Thermal Efficiency ◽  
Welding Speed ◽  
Empirical Relationship ◽  
Computational Method ◽  
Deep Penetration ◽  
Logarithmic Curve ◽  
40Kh13 Steel

The results of studying the interrelation that links the electron beam welding (EBW) thermal efficiency, thermophysical properties of the material, and welding speed are presented. Thermal efficiency was determined by a combined experimental and computational method based on measuring the penetration areas and evaluating the energy expenditure for melting with the known welding mode parameters. The study was carried out on a series of microsections prepared from welded joints of 5V titanium alloy, grade 40Kh13 steel, D16 duralumin, BrKh1Tsr bronze, and TsM2A molybdenum. It is shown that in EBW with deep penetration, its thermal efficiency increases with increasing the welding speed and decreasing the welded material thermal diffusivity. The experimental dependence of the thermal efficiency on the welding speed is approximated with sufficient accuracy by a logarithmic curve. Thus, in increasing the EBW speed from 20 to 120 m/h, the thermal efficiency increases from 54% to 67% for 5V titanium alloy, from 46% to 63% for 40Kh13 steel, and from 18% to 40% for D16 duralumin. The thermal efficiency in welding bronze (at an EBW speed of 30 m/h) and in welding TsMA molybdenum (at a speed of 20 m/h) was 15% on the average. An analysis of the thermal efficiency curve versus the dimensionless parameter vd/2a has shown that the thermal efficiency for all materials can be approximated by a single logarithmic dependence. An empirical relationship is proposed, using which the welding thermal efficiency can be determined as a function of welding speed and material thermal diffusivity.

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