Effects of base metal state on the microstructure and mechanical properties of Al–Mg–Si alloy friction stir-welded joints

2020 ◽  
Vol 56 ◽  
pp. 248-257 ◽  
Author(s):  
Z.Z. Xu ◽  
C.Y. Liu ◽  
B. Zhang ◽  
H.F. Huang ◽  
W. Cheng
Keyword(s):  
Mechanical Properties ◽  
Base Metal ◽  
Welded Joints ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
Metal State

scholarly journals Microstructure and Mechanical Properties of Friction Stir Welded Joints Between Commercially Pure Copper and Al 6351 Alloy

2017 ◽  
Vol 62 (3) ◽  
pp. 1819-1825
Author(s):  
V.C. Sinha ◽  
S. Kundu ◽  
S. Chatterjee
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Rotational Speed ◽  
Pure Copper ◽  
Stir Zone ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Commercially Pure ◽  
Microstructure And Mechanical Properties ◽  
Commercially Pure Copper

AbstractIn the present study, the effect of tool rotational speed on microstructure and mechanical properties of friction stir welded joints between commercially pure copper and 6351 Al alloy was carried out in the range of tool rotational speeds of 300-900 rpm in steps of 150 rpm at 30 mm/minutes travel speed. Up to 450 rpm, the interface of the joints is free from intermetallics and Al4Cu9intermetallic has been observed at the stir zone. However, Al4Cu9intermetallic was observed both at the interface and the stir zone at 600 rpm. At 750 and 900 rpm tool rotational speed, the layers of AlCu, Al2Cu3and Al4Cu9intermetallics were observed at the interface and only Al4Cu9intermetallics has been observed in the stir zone. The maximum ultimate tensile strength of ~207 MPa and yield strength of ~168 MPa along with ~6.2% elongation at fracture of the joint have been obtained when processed at 450 rpm tool rotational speed.

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.

scholarly journals Effect of Alloying Composition on Microstructure and Mechanical Properties of Ultranarrow Gap Welded Joints of U71Mn Rail Steel

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Lian Gong ◽  
Hui Liu ◽  
Cheng Lv ◽  
Lijun Zhao
Keyword(s):  
Mechanical Properties ◽  
Base Metal ◽  
Welded Joints ◽  
Alloy Composition ◽  
Rail Steel ◽  
Base Material ◽  
Average Hardness ◽  
Microstructure And Mechanical Properties ◽  
Fine Pearlite ◽  
The Impact

A new welding method, ultranarrow gap welding with constrained arc by flux band, is proposed to compensate for the low quality of rail thermite welded joints. This article presents the results of research on the microstructure and mechanical properties of ultranarrow gap welded joints of U71Mn rail steel made using three types of alloying composition content flux bands. Results indicated that the base metal metallographic microstructure consisted mainly of pearlitic, the HAZ was mainly composed of fine pearlite, and the microstructure of the welded bead was composed of acicular ferrite, while the weld grain size decreased as the alloy composition increased. The average hardness noticeably changed in weld metal as the alloy composition increased, and when the alloy composition reached 19%, the hardness was equivalent to the base material. The average hardness value of the HAZ (35.8 HRC) was higher than that of the base metal (24.8 HRC). The tensile strength increased, and the percentage elongation after fracture decreased with increasing alloying composition from 9% to 19%. The impact absorbing energies were decreased as the alloying composition increased. Consequently, all the mechanical properties of rail ultranarrow gap welding were higher than those of the standard requirements of the rail flash welding. And the optimal alloying composition of flux band was 19%.

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