Increase of the Elasticity and Strength of the Welded Joints for the Al-Mg-Li Alloy Made by the Laser Welding by Means of the Thermal Mechanical Processing

2018 ◽  
Vol 385 ◽  
pp. 385-390
Author(s):  
Aleksandr Malikov ◽  
Anatolii Orishich ◽  
Evgenij Karpov ◽  
Evgenij Sandalov
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Welded Joints ◽  
Thermal Processing ◽  
Mechanical Characteristics ◽  
Welded Joint ◽  
Strength Increase ◽  
Artificial Ageing ◽  
Mechanical Processing ◽  
Before And After

The paper deals with the analysis of the effect of the thermal mechanical processing on the mechanical characteristics (elasticity and tensile strength) of the welded joints of the aluminum alloy, the system Al-Mg-Li. The microstructures of the basic alloy and welded joint before and after the thermal processing are compared by electronic microscoping. The X-ray diffraction method is used to compare the phase composition. The concentration of the strengthening phase δʹ(Al3Li) reduces in the welded joint, which results in the low mechanical characteristics. The thermal processing, namely quenching, increases the concentration of the equilibrium S1 phase (Al2MgLi) in the welded joint as compared with an unquenched joint. The elasticity of the welded joint rises significantly at the almost constant strength, the value of the relative extension lies within the range of 2.4 – 19.2 % before and after quenching, respectively. Artificial ageing applied to the welded joint after the quenching gives the structurization of the S1 phase. The full thermal mechanical processing (quenching, elastic deformation, artificial ageing) of the welded joint of the aluminum alloy (the system AL-Mg-Li) results in the tensile strength increase up to 0.95 of the basic alloy strength.

Study on Microstructure and Properties of 5A06 Aluminum Alloy Welded Joint by Deep Cryogenic Treatment

2011 ◽  
Vol 314-316 ◽  
pp. 927-931 ◽  
Author(s):  
Shan Gao ◽  
Zhi Sheng Wu ◽  
Peng Fei Jin ◽  
Jun Jie Wang
Keyword(s):  
Aluminum Alloy ◽  
Welded Joints ◽  
Welded Joint ◽  
Cryogenic Treatment ◽  
Liquid Nitrogen Temperature ◽  
X Ray Diffraction ◽  
Deep Cryogenic Treatment ◽  
X Ray ◽  
Before And After ◽  
5A06 Aluminum Alloy

In this paper, some deep cryogenic treatment experiments are first applied to 5A06 aluminum alloy welded joint at liquid nitrogen temperature （-155°C ）for 4h, 8h, 10h respectively. 5A06 alloy welded joints before and after deep cryogenic treatment are observed by X-ray diffraction and scanning electrical microscopy. The experimental results have shown that the deep cryogenic treatment causesβphase of alloy to disperse and makes the grain smaller than that of joint before deep cryogenic treatment. Therefore, the mechanical properties of 5A06 alloy welded joints after deep cryogenic treatment are greatly improved.

scholarly journals Effect of Welding Wires Containing ZrB2 Particles on Microstructure and Mechanical Properties of Spray-Formed 7055 Aluminum Alloy TIG Welded Joints

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Ting Huang ◽  
Junhua Xu ◽  
Lihua Yu ◽  
Yunxuan Hu ◽  
Yun Cheng ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Welded Joints ◽  
Welded Joint ◽  
Testing Machine ◽  
Weld Zone ◽  
Tensile Testing Machine ◽  
Hardness Tester ◽  
7055 Aluminum Alloy

In this paper, a series of welding wires with ZrB2 particles were developed by the in situ reaction, and the ZrB2 particles were successfully introduced into the spray-formed 7055 aluminum alloy welded joints by TIG welding. The microstructure, hardness, and tensile strength of the welded joints were tested by metallographic microscope, SEM, EDS, Vickers hardness tester, and tensile testing machine. The results show that the microstructure of ZrB2/7055 welded joints is fine dendrites. The hardness of the weld zone of the ZrB2/7055 welded joint is higher than that of the 7055 welded joint. With the increase of ZrB2 particles’ content, the tensile strength of welded joints increases first and then decreases. When the content of ZrB2 particles is 1.5 wt.%, the tensile strength reaches the maximum value of 280 MPa. The tensile strength of the welded joint containing 1.5 wt.% ZrB2 particles is 14% higher than that of the pure 7055 aluminum alloy welded joint.

scholarly journals Improving the Properties of Laser-Welded Al–Zn–Mg–Cu Alloy Joints by Aging and Double-Sided Ultrasonic Impact Compound Treatment

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2742
Author(s):  
Furong Chen ◽  
Chenghao Liu
Keyword(s):  
Plastic Deformation ◽  
Tensile Strength ◽  
Tensile Properties ◽  
Welded Joints ◽  
Welded Joint ◽  
Weld Zone ◽  
Aging Treatment ◽  
Residual Tensile Stress ◽  
Impact Surface ◽  
Deformation Layer

To improve the loose structure and serious porosity of (Al–Zn–Mg–Cu) 7075 aluminum alloy laser-welded joints, aging treatment, double-sided ultrasonic impact treatment (DSUIT), and a combination of aging and DSUIT (A–DSUIT) were used to treat joints. In this experiment, the mechanism of A–DSUIT on the microstructure and properties of welded joints was analyzed. The microstructure of the welded joints was observed using optical microscopy, scanning electron microscopy, and electron backscatter diffraction (EBSD). The hardness and tensile properties of the welded components under the different processes were examined via Vickers hardness test and a universal tensile testing machine. The results showed that, after the aging treatment, the dendritic structure of the welded joints transformed into an equiaxed crystal structure. Moreover, the residual tensile stress generated in the welding process was weakened, and the hardness and tensile strength were significantly improved. After DSUIT, a plastic deformation layer of a certain thickness was generated from the surface downward, and the residual compressive stress was introduced to a certain depth of the joint. However, the weld zone unaffected by DSUIT still exhibited residual tensile stress. The inner microhardness of the joint surface improved; the impact surface hardness was the largest and gradually decreased inward to the weld zone base metal hardness, with a small improvement in the tensile strength. Compared with the single treatment process, the microstructural and mechanical properties of the welded joint after A–DSUIT were comprehensively improved. The microhardness and tensile strength of the welded joint reached 200 HV and 615 MPa, respectively, for an increase of 45.8% and 61.8%, respectively. Observation of the fractures of the tensile specimens under the different treatment processes showed that the fractures before the aging treatment were mainly ductile fractures while those after were mainly brittle fractures. After DSUIT of the welded joints, a clear and dense plastic deformation layer was observed in the fracture of the tensile specimens and effectively improved the tensile properties of the welded joints. Under the EBSD characterization, the larger the residual compressive stress near the ultrasonic impact surface, the smaller the grain diameter and misorientation angle, and the lower the texture strength. Finally, after A–DSUIT, the hardness and tensile properties improved the most.

Influence of Stress Concentration on Fatigue Property of Welded Joints of 5083 Aluminum Alloy

2013 ◽  
Vol 456 ◽  
pp. 451-455
Author(s):  
Jun Yang ◽  
Bo Li ◽  
Qiang Jia ◽  
Yuan Xing Li ◽  
Ming Yue Zhang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Fatigue Strength ◽  
Stress Concentration ◽  
Welded Joints ◽  
Weld Zone ◽  
Fatigue Property ◽  
Concentration Coefficient ◽  
5083 Aluminum Alloy ◽  
Stress Concentration Coefficient

Fatigue test of the welded joint of 5083 aluminum alloy with smooth and height of specimen and the weld zone than the high test measurement and theoretical stress concentration coefficient calculation, the weld reinforcement effect of stress concentration on the fatigue performance of welded joints. The results show that: Smooth tensile strength of specimens for 264MPa, fatigue strength is 95MPa, the tensile strength of the 36%. Higher tensile strength of specimens for 320MPa, fatigue strength is 70MPa, the tensile strength of the 22%. Higher specimen stress concentration coefficient is 1.64, the stress concentration to the weld toe becomes fatigue initiation source, and reduces the fatigue strength and the fatigue life of welded joints.

Statistical Tensile Strength Characteristics of Aluminum Alloy Pipe and Steel Pipe Friction Welded Joints

2000 ◽  
Vol 331-337 ◽  
pp. 1731-1736
Author(s):  
Gosaku Kawai ◽  
Koichi Ogawa ◽  
Ryoji Tsujino ◽  
Hiroshi Yamaguchi ◽  
Hiroshi Tokisue
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Welded Joints ◽  
Strength Characteristics ◽  
Steel Pipe

FEATURES OF REPAIR OF WELDED STRUCTURES OF LARGE THICKNESSES FROM TITANIUM ALLOY VT6ch.

2021 ◽  
pp. 34-43
Author(s):  
A.V. Sviridov ◽  
◽  
М.S. Gribkov ◽  
Keyword(s):  
Titanium Alloy ◽  
Residual Stresses ◽  
Elemental Composition ◽  
Welded Joints ◽  
Mechanical Characteristics ◽  
Electron Beam Welding ◽  
Welded Joint ◽  
Vacuum Annealing ◽  
Base Material ◽  
Welded Structures

The technology of electron-beam welding (EBW) of structures of large thickness made of titanium alloy Ti–6Al–4V has been developed. A complex of metallographic studies of welded samples has been carried out. Tests to determine the mechanical characteristics of repair welded joints, that these joints made by EBW are equal in strength to the base material. The analysis of the level of residual stresses in various parts of the welded joint after repeated repair passes has been carried out. It was found that the subsequent vacuum annealing reduces the level of residual stresses in welded joints to 50 %. The analysis of the elemental composition showed that the elemental composition of the samples from the center of the weld to the base metal practically does not change for welding with the number of repeated passes up to 3.

scholarly journals Evaluation of Tensile Strength and Fatigue Strength of 6061 Aluminum Alloy Friction Welded Joint

2002 ◽  
Vol 51 (9Appendix) ◽  
pp. 156-161
Author(s):  
Hiizu OCHI ◽  
Takeshi SAWAI ◽  
Yoshiaki YAMAMOTO ◽  
Masayuki KURITA ◽  
Koichi OGAWA ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Fatigue Strength ◽  
Welded Joint ◽  
6061 Aluminum Alloy

Microstructures and Mechanical Properties of Welded Joints of Several High Tensile Strength Steel

2018 ◽  
Vol 941 ◽  
pp. 224-229
Author(s):  
Takahiro Izumi ◽  
Tatsuya Kobayashi ◽  
Ikuo Shohji ◽  
Hiroaki Miyanaga
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weld Metal ◽  
Welded Joints ◽  
Welded Joint ◽  
Steel Plates ◽  
Fatigue Properties ◽  
High Tensile Strength ◽  
The Matrix ◽  
Microstructures And Mechanical Properties

Microstructures and mechanical properties of lap fillet welded joints of several high and ultra-high tensile strength steel by arc welding were investigated. Steel plates having tensile strength of 400 (SPH400W), 590 (SPC590Y, SPC590R), 980 (SPC980Y) and 1500 MPa (SAC1500HP) class with 2 mm thickness were prepared. Four types of joints were formed by MAG welding; SPH400W/SPH400W, SPC590Y/SPC590Y, SPC980Y/SPC980Y and SAC1500HP/SPC590R. In joints with SPC590Y, SPC980Y and SAC1500HP steel which matrixes are martensitic microstructures, the HAZ softens due to transformation of martensite into ferrite with precipitating cementite. By using high and ultra-high tensile strength steel, the weld metal is strengthened due to dilution of the matrix into the weld metal and thus tensile shear strength of the welded joint increases. In the fatigue test, similar S-N diagrams were obtained in the all welded joints investigated. It seems that the effect of stress concentration due to the shape of the welded joint on fatigue properties is larger than that of the strength of the matrix.

scholarly journals Evolution of Microstructure and Mechanical Properties in a Single-Stage Aged 7075 Aluminum Alloy Pulse Variable Polarity Plasma Arc Welded Joint

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 428
Author(s):  
Guowei Li ◽  
Yahong Liang ◽  
Furong Chen ◽  
Yongquan Han ◽  
Li Sun
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Aging Temperature ◽  
Welded Joint ◽  
Single Stage ◽  
Precipitate Size ◽  
7075 Aluminum Alloy ◽  
Plasma Arc ◽  
Variable Polarity ◽  
Variable Polarity Plasma Arc

A 7075 aluminum alloy was successfully welded by pulsed variable polarity plasma arc welding (PVPPAW) and the single-stage aging behavior of the 7075 aluminum alloy PVPPAW joint was systematically investigated. The results demonstrated that the tensile strength of the welded joints initially increased and then decreased with the increase of the single-stage aging temperature and time. After single-stage aging at 490 °C for 80 min and at 130 °C for 24 h, the tensile strength of the welded joint was 551 MPa, which was increased by 38.5% compared to the as-welded joint. Moreover, the conductivity was 25% international annealed copper standard (IACS) at room temperature, and the resistance to stress corrosion was improved. The main strengthening phases of the weld center were η′ and η phase. The average precipitate size slightly increased with the increase of the single-stage aging temperature, but no obvious change was observed with the increase of the single-stage aging time. The area fraction was initially increased and then decreased with the increase of the single-stage aging temperature and time.

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