scholarly journals The Microstructure and Mechanical Properties of Dual-Spot Laser Welded-Brazed Ti/Al Butt Joints with Different Groove Shapes

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5105
Author(s):  
Peng Li ◽  
Zhenglong Lei ◽  
Xinrui Zhang ◽  
Enze Cai ◽  
Yanbin Chen
Keyword(s):  
Temperature Field ◽  
Mechanical Performance ◽  
Al Alloys ◽  
Welding Wire ◽  
Butt Joints ◽  
Ductile Fractures ◽  
Weld Appearance ◽  
Brittle Fractures ◽  
Interfacial Intermetallic Compound ◽  
Beam Mode

Laser welding-brazing was performed to join Ti and Al together. The dual-spot laser beam mode was selected as the heat source in this study. Ti-6Al-4V and 6061-T6 Al alloys were selected as the experimental materials. Al-12Si welding wire was selected as the filler material. The effect of groove shape on the weld appearance, microstructure, temperature field, and mechanical performance of Ti/Al welded-brazed butt joints was investigated. The interfacial intermetallic compound (IMC) layer at the Ti/Weld brazing interface was inhomogeneous in joints with I-shaped and Y-shaped grooves. In Ti/Al joints with V-shaped grooves, the homogeneity of temperature field and IMC layer was improved, and the maximum thickness difference of IMC layer was only 0.20 μm. Nano-sized granular Ti7Al5Si12, Ti5Si3, and Ti(Al,Si)3 constituted the IMCs. The tensile strength of Ti/Al joints with V-shaped grooves was the highest at 187 MPa. The fracture mode transformed from brittle fractures located in the IMC layer to ductile fractures located in the Al base metal, which could be attributed to the improvement of the IMC layer at the brazing interface.

Microstructure and mechanical performance of autogenously fibre laser beam welded Ti-6242 butt joints

2017 ◽  
Vol 694 ◽  
pp. 110-120 ◽  
Author(s):  
Nikolai Kashaev ◽  
Dmitry Pugachev ◽  
Volker Ventzke ◽  
Fedor Fomin ◽  
Irmela Burkhardt ◽  
...  
Keyword(s):  
Laser Beam ◽  
Mechanical Performance ◽  
Fibre Laser ◽  
Butt Joints

scholarly journals Disk Laser Welding of Car Body Zinc Coated Steel Sheets / Spawanie Laserem Dyskowym Blach Ze Stali Karoseryjnej Ocynkowanej

2015 ◽  
Vol 60 (4) ◽  
pp. 2913-2922 ◽  
Author(s):  
A. Lisiecki ◽  
R. Burdzik ◽  
G. Siwiec ◽  
Ł. Konieczny ◽  
J. Warczek ◽  
...  
Keyword(s):  
Laser Welding ◽  
Mechanical Performance ◽  
Galvanized Steel ◽  
Coated Steel ◽  
Butt Joints ◽  
Beam Spot ◽  
Disk Laser ◽  
Car Body ◽  
Steel Sheets ◽  
Zinc Coated Steel

Autogenous laser welding of 0.8 mm thick butt joints of car body electro-galvanized steel sheet DC04 was investigated. The Yb:YAG disk laser TruDisk 3302 with the beam spot diameter of 200 μm was used. The effect of laser welding parameters and technological conditions on weld shape, penetration depth, process stability, microstructure and mechanical performance was determined. It was found that the laser beam spot focused on the top surface of a butt joint tends to pass through the gap, especially in the low range of heat input and high welding speed. All test welds were welded at a keyhole mode, and the weld metal was free of porosity. Thus, the keyhole laser welding of zinc coated steel sheets in butt configuration provides excellent conditions to escape for zinc vapours, with no risk of porosity. Microstructure, microhardness and mechanical performance of the butt joints depend on laser welding conditions thus cooling rate and cooling times. The shortest cooling time t8/5 was calculated for 0.29 s.

Microstructure and Mechanical Properties of Welded Joints of Cr18Ni30Mo2Al3Nb Alloy

2014 ◽  
Vol 636 ◽  
pp. 89-92
Author(s):  
Rui Luo ◽  
Xiao Nong Cheng ◽  
Gui Fang Xu ◽  
Dong Sheng Li ◽  
Shun Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Arc Welding ◽  
Comparative Research ◽  
Mechanical Performance ◽  
Tensile Fracture ◽  
Welding Parameters ◽  
Butt Joints ◽  
Argon Flow ◽  
Scaning Electron Microscopy

In this present study, A comparative research on the mechanical properties of the dissimilar welded joints of 800H and Cr18Ni30Mo2Al3Nb was investigated. Butt joints were made using argon tungsten-arc welding (TIG). The TIG joint was made using well established welding parameters (i.e., current ampere of 110~120A, welding rate of 105~115mm/min, argon flow 8~10L/min and voltage of 12V). Mechanical behavior of joints was evaluated by room temperature and high temperature (650°C) tensile testing, and hardness testing, respectively. The microstructure of joint was characterized via optical microscopy, and the morphology of tensile fracture was observed by scaning electron microscopy. As can be seen from the experimental results, clearly shown that Cr18Ni30Mo2Al3Nb has better mechanical performance of welded joint than 800H.

Mechanical Performance of a Thermoelectric Composite in the Vicinity of an Elliptic Inhomogeneity

2019 ◽  
Vol 72 (4) ◽  
pp. 429-447 ◽  
Author(s):  
K Song ◽  
H P Song ◽  
P Schiavone ◽  
C F Gao
Keyword(s):  
Temperature Field ◽  
Electric Current ◽  
Current Density ◽  
Mechanical Performance ◽  
Matrix Material ◽  
Electric Current Density ◽  
Stress Distributions ◽  
Elastic Fields ◽  
Surrounding Matrix ◽  
Elliptic Inhomogeneity

Summary Thermal stress induced by an uneven temperature field and mismatched thermal expansion is known to be a dominating factor in the debonding mechanism that threatens reliability and ultimately leads to failure in thermoelectric (TE) composites. Accordingly, we analyse the stress distributions in a TE composite induced by the presence of an elliptic inhomogeneity embedded in the surrounding matrix material. Using complex variable methods, we obtain closed-form representations of the thermal–electric and thermal–elastic fields and find that the temperature field around the inhomogeneity is reduced dramatically by the application of a remote electric current density without affecting the temperature difference across the inhomogeneity–matrix interface. This ensures the conversion efficiency of the TE composite while improving its reliability. Numerical results illustrate that a suitable choice of electric current density can prevent interfacial debonding via the suppression of the maximum positive normal stress on the interface.

scholarly journals Laser Welding of New Grade of Advanced High Strength Steel STRENX 1100 MC

2017 ◽  
Vol 62 (3) ◽  
pp. 1651-1657 ◽  
Author(s):  
A. Kurc-Lisiecka ◽  
J. Piwnik ◽  
A. Lisiecki
Keyword(s):  
Laser Welding ◽  
Base Metal ◽  
Mechanical Performance ◽  
High Strength ◽  
Carbon Equivalent ◽  
Welding Parameters ◽  
Low Carbon ◽  
Butt Joints ◽  
Significant Drop ◽  
Metal Impact

AbstractThe article presents results of investigations on autogenous laser welding of new grade STRENX 1100 MC steel. The modern Disk laser was applied for of 5.0 mm thick butt joints welding. The influence of laser welding parameters, mainly the energy input of laser welding on the penetration shape, weld quality, structure and mechanical performance was investigated. It was found that the investigated steel has surprisingly low carbon equivalent CET just 0.328, and also relatively high temperature of martensitic transformation Msat 430.6°C. Despite very rapid cooling times t8/5in a range from 0.6 to 1.3 s, thus rapid solidification there was no tendency to cracking of weld metal or HAZ. Significant drop of microhardness in the HAZ resulted in a decrease of tensile strength of joints, compared to the base metal. Impact toughness of test joints was at only 50÷60% of the base metal.

Coupled Simulation on Temperature Field and Microstructure Formation Process of K4169 Superalloy Blade in Investment Casting

2012 ◽  
Vol 217-219 ◽  
pp. 330-333
Author(s):  
Han Wu Liu ◽  
Hong De Ren ◽  
De Chao Dong
Keyword(s):  
Temperature Field ◽  
Phase Change ◽  
Formation Process ◽  
Mechanical Performance ◽  
Grain Structure ◽  
Solute Diffusion ◽  
Heat Radiation ◽  
Transient Temperature ◽  
Time Step ◽  
Temperature State

In order to control the grain structure of K4169 superalloy blade which affects its mechanical performance and ability of resistance to corroding in high temperature state, the transient temperature field distributions were analyzed by using equivalent thermal entropy method with the consideration of the practical boundary conditions, such as, heat exchange and heat radiation in solidification, and the relationships between temperature and time of every point on vertical section and cross section during phase change heat transference process of K4169 superalloy were obtained. The changes of solid phase fraction after every time step were calculated basing on the model of equiaxed dendrite growth solute diffusion put forward by Rappaz and other persons. we used the data to modify the temperature in the same step when phase change latent heat was released. The Cell Automaton technology was adopted to coupled simulate the grain structure formation process of K4169 superalloy blade with its temperature fields using continuous nucleation model and kinetic model of dendrite tip growth. These simulation results which coincided much well with the ones of experiment test have played a very important role in studying superalloy mechanical performance and ability of resistance to corroding of K4169 alloy blades.

Study on the Effect of Homemade Welding Wire Contaning Ni, Cr Elements on the Weldability of Industrial Pure Aluminum

2013 ◽  
Vol 834-836 ◽  
pp. 839-842
Author(s):  
Yan Hong Zhao ◽  
Liang Jun Gao ◽  
Yong Sun ◽  
Wen Dong Song
Keyword(s):  
Mechanical Properties ◽  
Performance Test ◽  
Mechanical Performance ◽  
Pure Aluminum ◽  
Welding Process ◽  
Filler Materials ◽  
Welding Wire ◽  
Welding Joint ◽  
Microstructure And Mechanical Properties ◽  
Welding Properties

Industrial pure aluminum has been widely used in industry. However, it caused great difficulties in welding process due to its characteristics such as easy oxidation, high thermal conductivity and specific volume, low melting point. In order to overcome this problem, improving the welding quality of industrial pure and reducing the welding defects is of great significance. In this paper, the weldability of 1050A industrial pure aluminum plate (5 mm thick) with HS331, SAl-2, 1050A leftover materials and homemade welding wire with Ni-Cr alloy as four different filler materials was studied by using manual TIG welding. Metallographic test and mechanical performance test were used to assess microstructure and mechanical properties of the resulting welding joint. The results show that the microstructure and mechanical properties of the resulting welding joint with homemade welding wire with Ni-Cr alloy is relatively better than the others, which offers important implication for the improvement of the welding properties of industrial pure aluminum.

Performance Analysis and Optimization of Flange Bolt Joint under the Influence of Inhomogeneous Temperature Field

2011 ◽  
Vol 121-126 ◽  
pp. 1656-1662
Author(s):  
Qing Wang ◽  
Xian Jun Zhou ◽  
Zhi Liang Liu ◽  
Hong Jie Bi
Keyword(s):  
Temperature Field ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Inhomogeneous Temperature ◽  
Inhomogeneous Temperature Field ◽  
Joint Parameters ◽  
The Difference ◽  
Disc Spring ◽  
Different Parts ◽  
Better Than

A three-dimensional mechanical model and a transcalent model of flange bolt joint were built, considering the nonlinearity of gasket and the contact problem, the effect of inhomogeneous temperature field and its variation to pressure of bolt and gasket was studied, and the joint parameters of two schemes were compared; based on the orthogonal text, two bolt system schemes, adding disc spring and adding sleeve, were experimentally studied. The investigation showed that the sealability of different parts of the gaskets is different, owing to the difference of each bolt in radial and axial displacement under the influence of inhomogeneous temperature field, and the fatigue of gasket and bolt is easily caused; the scheme of disc spring is better than sleeve, and the disc spring, whose thickness is 0.9mm, was selected to improve the mechanical performance of bolt system.

scholarly journals Study on the Mechanical Performance of Dissimilar Butt Joints between Low Ni Medium-Mn and Ni-Cr Austenitic Stainless Steels Processed by Gas Tungsten Arc Welding

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1439
Author(s):  
I. Reda Ibrahim ◽  
Mahmoud Khedr ◽  
Tamer S. Mahmoud ◽  
Hamed A. Abdel-Aleem ◽  
Atef Hamada
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Arc Welding ◽  
Mechanical Performance ◽  
Gas Tungsten Arc Welding ◽  
Uniaxial Tensile ◽  
Butt Joints ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

In the present work, dissimilar butt joints between a low-Ni, medium-Mn austenitic stainless steel, M-Mn SS, and a Ni-Cr austenitic stainless steel, Ni-Cr SS, were processed by utilizing the gas tungsten arc welding (GTAW) technique at different heat inputs. A filler metal of ER308 was employed in the welding process. The filler yields 480 MPa, which is equivalent to the yield strength of M-Mn SS. The microstructural analysis and mechanical performance (i.e., tensile strength and hardness properties) of the concerned joints were studied by using an optical microscope and uniaxial tensile tests, respectively. The results revealed that a duplex structure from austenite matrix and delta ferrite is promoted in the fusion zone (FZ) of the dissimilar joints processed with low and high energy inputs (0.486 kJ/mm and 0.558 kJ/mm). The FZ of the specimens welded at high heat input exhibited the lowest hardness value (151.2 HV) in comparison to heat affected zone (HAZ) (166.3 HV). Moreover, the joints exhibited a low tensile strength of 610 MPa. The achieved strength is significantly lower than the strengths of the base metals (BMs) M-Mn SS and Ni-Cr SS. This is mainly attributed to the inhomogeneous dendritic structure of the FZ with Cr-carbides precipitation.

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