scholarly journals Effect of pulse frequency on laser welding on SiCp/6061 aluminum alloys with powder

2021 ◽  
Vol 2079 (1) ◽  
pp. 012022
Author(s):  
Yongchao Jian ◽  
Yan Shi
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloys ◽  
Laser Welding ◽  
Base Metal ◽  
Welded Joints ◽  
Molten Pool ◽  
Particle Distribution ◽  
Pulse Frequency ◽  
Uneven Distribution

Abstract Because of the uneven distribution of reinforcement particles in the molten pool during laser welding of SiCp/6061Al composites with powder, the effect of pulse frequency on the homogenization was studied in this paper. The pulse frequency of welding is changed and the macro morphology of the weld is studied by metallographic microscope. The particle uniformity of reinforcing phase and the porosity of molten pool at different frequencies were compared. The tensile strength of welded joints at different frequencies was tested by universal tensile machine. Finally, when the pulse frequency is 160Hz, the particle distribution of reinforcing phase is the most uniform and the tensile strength is the largest. The tensile strength reaches 267.06MPa, reaching 69.1% of the base metal. When the pulse frequency is 320Hz, the porosity of the weld is the lowest, reaching 1.75%.

scholarly journals A Comparison of Tensile Properties of Single-Sided and Double-Sided Laser Welded DP600 Steel Sheets

2019 ◽  
Vol 26 (2) ◽  
pp. 173-178
Author(s):  
Oguz TUNCEL ◽  
Hakan AYDIN
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Base Metal ◽  
Automotive Industry ◽  
Welded Joints ◽  
Yttrium Aluminum Garnet ◽  
High Strength ◽  
Pulse Frequency ◽  
Steel Sheets ◽  
Automotive Parts

Dual Phase (DP) steels are the most commonly used steels in the automotive industry to reduce vehicle weight and improve car safety. DP600 steel is one of the most used steels for the automotive industry because this steel has high strength and good elongation properties. During the manufacture of automotive parts, welding is the most commonly used joining process, and especially the laser welding is getting more and more importance. This study was executed to evaluate how the welding type (single-sided and double-sided) affects the tensile properties of Nd:YAG (Neodymium-Doped Yttrium Aluminum Garnet; Nd:Y3Al5O12) laser welded DP600 steel sheets using different pulse frequencies. The laser welded samples were investigated by the methods of tensile test and fractography. Experimental results indicated that the tensile properties varied significantly depending on the welding type and pulse frequency. The tensile properties of the double-sided laser welded joints were significantly higher than those of the single-sided laser welded joints. Tensile strength and elongation of the single-sided and the double-sided laser welded joints increased almost linearly with increasing pulse frequency. The higher pulse frequency resulted in larger fully bonded section size, which led to higher tensile properties. The maximum tensile strength and elongation (611 MPa and 10.06 %) were obtained with the double-sided laser welded joint in the pulse frequency of 8.5 Hz. The tensile strength of this joint was almost equal to that of the base metal, but its elongation value was lower that of the base metal.

scholarly journals Effect of Pulse Frequency on Microstructure and Mechanical Properties of 2198 Al-Li Alloy Joints Obtained by Ultrahigh-Frequency Pulse AC CMT Welding

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 79 ◽  
Author(s):  
Liwei Wang ◽  
Yingchao Suo ◽  
Chaofeng Wu ◽  
Dianlong Wang ◽  
Zhimin Liang
Keyword(s):  
Tensile Strength ◽  
Welded Joints ◽  
Electromagnetic Force ◽  
Molten Pool ◽  
High Performance ◽  
Pulse Frequency ◽  
Ultrahigh Frequency ◽  
Cold Metal Transfer ◽  
Cold Metal ◽  
Frequency Pulse

In this study, 2198 Al-Li alloy, a low density and high-performance material for aerospace equipment, was welded using ultrahigh-frequency pulse alternating current with cold metal transfer (UHF-ACCMT). Influence of different ultrahigh-frequency on the formation, porosity, microstructure, microhardness and tensile strength of the welded joints were investigated. The results showed that the coupled ultrahigh-frequency current generated electromagnetic force to stir the liquid metal of molten pool. The weld formation became much better with metallic luster and uniform ripples at frequency of 60 kHz and 70 kHz. The porosity was the minimum at frequency of 60 kHz. Furthermore, the molten pool was scoured and stirred by the electromagnetic force which provided the thermal and dynamic conditions for nucleation and grain refinement, the width of fine equiaxed grain zone became larger, and the number of equiaxed non-dendrite grains increased. With the grain refining and crystallize transition, the average microhardness and tensile strength of the joints at frequency of 60 kHz reached up the highest value, 116 HV0.1 and 338 MPa, respectively. The fracture of the welded joints presented the characteristics of quasi-cleavage fracture.

Influence of Rotary Friction Welding Parameters on Tensile Strength and Length of TMAZ of Dissimilar Welded Joints from 32G2 and 40KhN Steels

2021 ◽  
Vol 410 ◽  
pp. 299-305
Author(s):  
Artem S. Atamashkin ◽  
Elena Y. Priymak ◽  
Elena A. Kuzmina
Keyword(s):  
Tensile Strength ◽  
Base Metal ◽  
Process Parameters ◽  
Welded Joints ◽  
Friction Welding ◽  
Tensile Tests ◽  
Welding Parameters ◽  
Rotary Friction Welding ◽  
Study Results ◽  
Friction Pressure

In this work, pipe billets with a diameter of 73 mm and a wall thickness of 9 mm from steels 32G2 and 40KhN are friction welded with an aim to optimize the process parameters. The friction pressure, the forging pressure and the length of the fusion varied. After the implementation of various welding modes, tensile tests and metallographic studies were carried out. The optimal welding parameters have been established, which make it possible to obtain tensile strength at the level of the 32G2 base metal. The study results of the microstructure and SEM fractographs after the optimal welding mode are presented.

Laser Welding Conditions to Improve Tensile Strength and Fatigue Strength of a Lap Joint in Aluminum Alloys

2007 ◽  
Vol 35 (4) ◽  
pp. 100077
Author(s):  
M. R. Mitchell ◽  
R. E. Link ◽  
Kyohei Kawamoto ◽  
Shintaro Yoshimitsu ◽  
Hiroshi Noguchi ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Aluminum Alloys ◽  
Laser Welding ◽  
Lap Joint

Tensile Strength of Forged Ti-6Al-4V Welded Joints by Electronic Beam Welding

2011 ◽  
Vol 255-260 ◽  
pp. 132-136
Author(s):  
Hong Yu Qi ◽  
Jian Xie ◽  
Dong Pan ◽  
Shao Lin Li ◽  
Xiao Guang Yang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Base Metal ◽  
Welded Joints ◽  
Empirical Relationship ◽  
Weld Zone ◽  
Structure Design ◽  
Microstructure And Mechanical Properties ◽  
Welded Structure ◽  
Static Tensile

Forged Ti-6Al-4V welded structure by electronic beam welding (EBW) as integrally bladed disk (blisk) structure in advanced aero-engine has been widely applied. It is necessary to analyze microstructure and mechanical properties of Ti-6Al-4V welded joints by EBW for failure analysis and structure design of blisk. Firstly the microstructure and mechanical properties of forged Ti-6Al-4V welded joints was focused on. Grains in the weld zone become coarse and large gradient organization structure appears in the heat affected zone (HAZ), which presents significant local heterogeneity. Microhardness of the weld zone is about 20% higher than that of the base metal. The size of different region of the welded joints was estimated. Then static tensile test of three different specimens were carried on. Experiment results show that the tensile and yield strength of welded joints are not less than that of the base metal. Finally the empirical relationship between strength and hardness of Ti-6Al-4V alloy is established. Tensile strength of the weld zone and the base metal were estimated. Compared to experiment data, the deviation is 3.56%, 0.097% respectively.

Prevention of Fracture of Cracked Steel Bars Using Laser: Part III—Case of High Carbon Steel

1988 ◽  
Vol 110 (4) ◽  
pp. 319-324
Author(s):  
Akira Kato
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Carbon Steel ◽  
Laser Welding ◽  
Base Metal ◽  
High Carbon Steel ◽  
High Carbon ◽  
Bending Fatigue ◽  
Static Tensile ◽  
Bending Fatigue Strength

The effect of laser welding on prevention of the fracture of cracked shafts of a high carbon steel are presented. Static tensile strength and rotary bending fatigue strength were obtained using shaft specimens of AISI W1 which were welded by a CO2 laser around a precrack. Since the welded region became extremely hard and brittle, both the strengths of laser-welded specimens were lower than those of non-welded specimens. However, the strengths were increased higher than those of non-welded specimens after tempering the specimens. It was found that when tempered at 600°C after laser welding, the rotary bending fatigue strength of specimens with a crack smaller than 12 mm rose similar to that of the base metal, and when tempered at 700° C, the static tensile strength of specimens with a crack smaller than 12mm rose similar to that of the base metal. Therefore, it was shown that the laser welding is very effective to prevent fracture of high carbon steels.

scholarly journals Effect of Reversed Austenite on Mechanical Properties of ZG06Cr13Ni4Mo Repair Welded Joint

Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Yunhai Su ◽  
Zuyong Wei ◽  
Gang Li ◽  
Xiangwen Zhang ◽  
Hedi Ci ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Base Metal ◽  
Welded Joints ◽  
Welded Joint ◽  
Lath Martensite ◽  
Optical Microscope ◽  
Reversed Austenite ◽  
Repair Welding ◽  
Gas Tungsten Arc

In this work, gas tungsten arc welding (GTAW) was used to repair ZG06Cr13Ni4Mo martensitic stainless steel. Repair welding occurred either once or twice. The changes in the microstructure and properties of the repair welded joints were characterized by optical microscope (OM), scanning electron microscope (SEM), electron backscattering diffraction (EBSD), tensile and impact tests. The effects of reversed austenite in repair welded joints on microstructure and mechanical properties were studied. The results show that the microstructure of the welded joint after repair welding consists of a large amount of martensite (M) and a small amount of reversed austenite (A), and the reversed austenite is distributed at the boundary of martensite lath in fine strips. With the increase in the number of welding repairs, the content of reversed austenite in the welded joint increases. The microstructure in the repair welded joints is gradually refined, the microstructure in the once and twice repaired joints is 45.2% and 65.1% finer than that in the casting base metal, respectively. The reversed austenite presented in the repair welded joints decreases the tensile strength by 4.8% and 6.7%, increases the yield strength by 21.3% and 26.4%, and increases the elongation by 25% and 56%, respectively, compared with the casting base metal. In addition, the reversed austenite mainly nucleates and grows at the boundary of lath martensite. The refinement of the martensite structure was due to the generation of reversed austenite and the refinement of original austenite grain by the welding thermal cycle. After repair welding, the reverse austenite appeared in the repair welded joints and the tensile strength decreased slightly, but the plastic toughness was significantly improved, which was conducive to the subsequent service process.

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