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Microstructure and property of the Ti-24Al-15Nb-1.5Mo/TC11 joint welded by electron beam welding

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International Journal of Minerals,Metallurgy and Materials 2009年第5期16卷 568-575页

作者： Ying-ying Liu Ze-kun Yao Hong-zhen Guo Hang-hang Yang College of Materials Science and Engineering Northwestern Polytechnical University Xi＇an 710072 China

The Ti-24Al-15Nb-1.5Mo alloy, in the as-forged and heat-treated states, was joined to the as-forged TC 11 titanium alloy by electron beam welding with the heat inputs of 135 and 150 kJ/m. Then the microstructure and property of the Ti-24Al-15Nb- 1.5Mo/TC 11 welding interface were investigated. The results show that the phase constitution of the weld is not related to the heat input, and is mainly composed of α＇ phase. Moreover, the intermetallic phases of TiEAlNb, MoNb, NbaAl, and TiAl3 are formed in the weld zone. Therefore, the microhardness value of the weld zone is higher than that of the other portions in the same sample. The profile of the weld is asymmetrically fimnel-like. The grain sizes of the weld and its heat-affected zones are increased with increasing heat input. There is an obvious difference in the element content of the welding interface; only the alloying elements in the fusion zone reach a new balance during solidification.

关键词： titanium alloys electron beam welding heat input microstructure property

electron beam welding of SiCp/2024 and 2219 aluminum alloy

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China welding 2019年第4期28卷 51-55页

作者： Chen Guoqing Zhang Binggang Yang Yong Feng Jicai State Key Laboratory of Advanced welding and Joining Harbin Institute of TechnologyHarbin 150001China

SiCp/2024 matrix composites reinforced with SiC particles and 2219 aluminum alloy were joined via centered electron beam welding and deflection beam welding,respectively,and the microstructures and mechanical properties of these joints were *** results revealed that SiC particle segregation was more likely during centered electron beam welding(than during deflection beam welding),and strong interface reactions led to the formation of many Al4C3 brittle intermetallic ***,the tensile strength of the joints was 104 *** interface reaction was restrained via deflection electron beam welding,and only a few Al4C3 intermetallic compounds formed at the top of the joint and heat affected zone of SiCp/***-cleavage fracture occurred at the interface reaction layer of the base *** methods yielded a hardness transition zone near the SiCp/2024 fusion zone,and the brittle intermetallic Al4C3compounds formed in this zone resulted in high hardness.

关键词： SiCp/2024 matrix composite 2219 aluminum alloy electron beam welding microstructure mechanical properties

Effect of interlayer addition on microstructure and mechanical properties of NiTi/stainless steel joint by electron beam welding

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Journal of Materials Science & Technology 2021年第2期61卷 16-24页

作者： H.Niu H.C.Jiang M.J.Zhao L.J.Rong CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of ScienceShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei230026China

NiTi/Stainless Steel(SS) sheets have been welded via a vacuum electron beam welding process, with three methods(offsetting electron beam to SS side without interlayer, adding Ni interlayer and adding Fe Ni interlayer), to promote mechanical properties of the Ni Ti/SS joints. The joints with different interlayers are all fractured in the weld zone near the Ni Ti side, which is attributed to the enrichment of intermetallic compounds including Fe2 Ti and Ni3 Ti. The fracture mechanisms of different joints are strongly dependent on the types of interlayers, and the joints without interlayer, adding Ni interlayer and adding Fe Ni interlayer exhibit cleavage fracture, intergranular fracture and mixed fracture composed of cleavage and tearing ridge, respectively. Compared with the brittle laves phase Fe2 Ti, Ni3 Ti phase can exhibit certain plasticity, block the crack propagation and change the direction of crack propagation. The composite structure of Ni3 Ti and Fe2 Ti will be formed when the Fe Ni alloy is taken as the interlayer, which provides the joint excellent mechanical properties, with rupture strength of 343 MPa.

关键词： NiTi Stainless steel electron beam welding Interlayer Mechanical property

Fatigue crack growth of titanium alloy joints by electron beam welding

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Rare Metals 2014年第5期33卷 516-521页

作者： Hong-Yu Qi Hao Shi Shao-Lin Li Xiao-Guang Yang School of Jet Propulsion Beijing University of Aeronautics and Astronautics

electron beam welding（EBW） has been widely used in the manufacture of titanium alloy welded blisk for aircraft engines. Based on fatigue crack growth tests on titanium alloy electron beam welding（EBW） joints, mechanism of fracture was investigated under scanning electron microscope（SEM）. The results show that fatigue crack growth rate increases as the experimental load increases under the same stress ratio and stress intensity factor range. At the beginning of crack growth, the extension mechanism of fatigue crack is the typical mechanism of cleavage fracture. In the steady extention stage, crack extends along the weld seam ***, crack growth direction changes to extend along the base metal. The extension mechanism of fatigue crack in the weld seam is the main mechanism of cleavage fracture and the extension mechanism of fatigue crack in the base metal is the main extension mechanism of fatigue band. In the instantaneous fracture stage, the extension mechanism of fatigue crack is the typical dimple-type static fracture *** growth was simulated by conventional finite element method and extended finite element method.

关键词： Microforming Ti–6Al–4V alloy electron beam welding Fatigue crack growth Fracture analysis

Tensile properties and failure analysis of Ti–6Al–4V joints by electron beam welding

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Rare Metals 2016年第6期35卷 450-455页

作者： Xiao-Guang Yang Shao-Lin Li Hong-Yu Qi School of Energy and Power Engineering Beijing University of Aeronautics and Astronautics

The microstructural and mechanical characterization of electron beam welded joints of forged Ti-6Al- 4V were investigated. Microhardness tests indicate that the hardness of the fusion zone （FZ） is higher than that of the heat-affected zone （HAZ） and base metal. The tensile results show that the mechanical properties of the welded joints are comparable with those of the base metal in terms of static strength and are in accordance with the relationship between microstructure and mechanical properties of welded joints. The ultimate tensile strength of the weld is equal to that of the hourglass joint, which indicates that the mechanical properties of the longitudinal FZ and those of the transverse FZ are the same. Macromechanical behavior and macrofracture and microfracture of the base material, joint, and weld specimens are observed. A comparison among the three types of specimen fracture phenomena reveals the following distinctive differences：（1） the fracture mode, （2） the micrograph of the dimple pattern at the central region, and （3） the size of the dimple at the central region and the transition region.

关键词： electron beam welding Microstructure Mechanical properties Failure model

Effect of beam current on microstructures and mechanical properties of joints of TZM/30CrMnSiA by electron beam welding

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Chinese Journal of Aeronautics 2021年第8期34卷 122-130页

作者： Ting WANG Bin YU Yifan WANG Siyuan JIANG State Key Laboratory of Advanced welding and Joining Harbin Institute of Technology at WeihaiWeihai 264209China Shandong Provincial Key Laboratory of Special welding Technology Harbin Institute of Technology at WeihaiWeihai 264209China

electron beam welding experiments of TZM alloy and 30CrMnSiA steel butt joints were carried out with different beam *** and chemical compositions of typical zones were analyzed by optical microscopy,scanning electron microscopy and X-ray *** mechanical properties of the joints were evaluated by tensile strength ***,nanoindentation tests were carried out to compare the brittleness of the reaction layer and other typical *** results illustrated that the reaction layer at the interface between fusion zone(FZ)and TZM alloy was the weak position of the joint,which was divided into Fe2Mo layer and a mixture layer of Fe2Mo and a-Fe *** the beam current increased,the thickness of the Fe2Mo layer decreased,which resulted in the increasing of the tensile strength of the *** the beam current exceeded 24 m A,the formation of the joint was poor with a low tensile *** the beam current was 24 mA,the joint presented the highest strength of 191.3 MPa and the joint fractured along the Fe2Mo layer near the TZM alloy side with a brittle fracture mode.

关键词： 30CrMnSiA electron beam welding Mechanical properties Microstructure TZM alloy

Effects of different aging treatments on microstructures and mechanical properties of Al-Cu-Li alloy joints welded by electron beam welding

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Chinese Journal of Aeronautics 2018年第2期31卷 363-369页

作者： Shaogang WANG Yan HUANG Li ZHAO College of Material Science and Technology Nanjing University of Aeronautics and Astronautics

Post-weld single aging treatment（solution treatment at 510 ℃ for 1 h, water quenching,and aging at 155 ℃ for 16 h） and post-weld double aging treatment（solution treatment at 510 ℃ for 1 h, water quenching, aging at 155 ℃ for 16 h, and aging at 130 ℃ for 12 h） are carried out on Al-Cu-Li alloy joints by electron beam welding（EBW） respectively. The effects of aging treatments on microstructures and mechanical properties of welded joints are investigated. Results show that the mechanical properties of welded joints are obviously improved after both aging treatments. The strength coefficient of joints is increased from 0.64 in an as-welded condition（AW） to 0.90 after post-weld double aging treatment. Microstructure analysis shows that the precipitates of the fusion zone within grains and grain boundaries are less in the AW condition. After post-weld heat treatment（PWHT）, a lot of fine needle-like phases T_1（Al_2 Cu Li） precipitate in grain boundaries of the fusion zone, and more horseshoe-shaped β＇（Al_3 Zr） particles precipitate within grains. In addition,grains of the fusion zone are refined after post-weld double aging treatment, which leads to an effect of grain refinement strengthening. Consequently, the mechanical properties of welded joints are greatly improved.

关键词： Al-Li alloy electron beam welding Mechanical properties Microstructure Post-weld heat treatment

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by electron beam welding

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Acta Metallurgica Sinica(English Letters) 2015年第7期28卷 922-930页

作者： Pu Xie Hai-Yan Zhao Bing Wu Shui-Li Gong Department of Mechanical Engineering Tsinghua University State Key Laboratory of Tribology Tsinghua University Beijing Aeronautical Manufacture Technology Research Institute

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates（50 mm thick） by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS *** the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement *** test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld *** peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.

关键词： electron beam welding Residual stress Finite element method Contour method Titanium alloy

electron beam welding of precipitation hardened CuCrZr alloy:Modeling and experimentation

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Transactions of Nonferrous Metals Society of China 2020年第8期30卷 2156-2169页

作者： Rajveer SINGH Sachin SINGH P.K.C.KANIGALPULA J.S.SAINI Department of Mechanical Engineering Thapar Institute of Engineering and TechnologyPatiala-147004PunjabIndia

In order to maintain the structural consistency during the welding of precipitation hardened copperchromium-zirconium(PH-CuCrZr)alloy components,electron beam welding(EBW)process was *** study and numerical modeling of EBW process during welding of PH-CuCrZr alloy components were carried out.A 3D finite element model was developed to predict the output responses(bead penetration and bead width)as a function of EBW input parameters(beam current,acceleration voltage and weld speed).A combined circular and conical source with Gaussian heat distribution was used to model the deep penetration characteristic of the EBW *** modeling was carried out by developing user defined function in Ansys *** predictions were compared with the experimental results which had a good agreement with each *** developed model can be used for parametric study in wide range of problems involving complex geometries which are to be welded using EBW *** present work illustrates that the input current with a contribution of 44.56%and 81.13%is the most significant input parameter for the bead penetration and bead width,respectively.

关键词： electron beam welding bead width bead penetration modeling copper-chromium-zirconium alloy