Study on Friction Stir Spot Welding Procedure of AZ31 Magnesium Alloy

2011 ◽  
Vol 239-242 ◽  
pp. 1437-1441
Author(s):  
Cheng Gang Ding ◽  
Chuan Jun Guo ◽  
Gao Feng Quan ◽  
Feng Wu

The study has examined the influence of FSSW (friction stir spot welding) parameters (rotation speed, downward compression and welding period) on mechanical property (shear resistance force) by conducting FSSW experiments on 3mm-thick AZ31 magnesium alloy plates under the orthogonal design. According to the experiment result, welding period is the major factor that decides the shear resistance force of FSSW joints, optimum welding parameters are: rotation speed(RS) 2450r/min, welding period(WP) 8s, downward compression of the tool shoulder(DCTS) 0.2mm. Microstructure observations show that tiny and even equiaxial grains are formed in WN (Weld nugget zone) and coarse grains with uneven sizes are formed in TMAZ(thermo-mechanically affected zone) and HAZ (Heat affected zone).

2021 ◽  
pp. 109997
Author(s):  
Banglong Fu ◽  
Junjun Shen ◽  
Uceu F.H.R. Suhuddin ◽  
Ayrton A.C. Pereira ◽  
Emad Maawad ◽  
...  

2012 ◽  
Vol 706-709 ◽  
pp. 3016-3021 ◽  
Author(s):  
L.C. Campanelli ◽  
U.F.H. Suhuddin ◽  
Jorge Fernandez Dos Santos ◽  
N.G. Alcantara

Friction spot welding (FSpW) is a recent solid state welding process developed and patented by GKSS Forschungszentrum (now Helmholtz-Zentrum Geesthacht), Germany. A spot-like connection is produced by means of an especially designed non-consumable tool consisting of pin, sleeve and clamping ring that creates a joint between sheets in overlap configuration through frictional heat and plastic deformation. FSpW offers many advantages over conventional spot joining techniques including high energy efficiency, surface quality and environmental compatibility. Comparing with friction stir spot welding, FSpW produces a weld without keyhole on the surface at the end of the joining process. In the present study, the possibility of joining AZ31 magnesium alloy by FSpW technique was evaluated by using different welding parameters (rotational speed, plunge depth and dwell time), aiming to produce high quality connections. Microstructural features were analyzed by light optical microscope and mechanical performance was investigated by microhardness test and lap shear test. Microstructure analysis revealed that defects free welds could be produced. A slight decrease in grain size of the stir zone was observed causing a slight increase in the microhardness of this region. The preliminary lap shear data demonstrated that the weld strength is comparable to other welding process.


Author(s):  
Jicheng Gao ◽  
Jiachen Dong ◽  
Sunyi Zhang ◽  
Liang Yu ◽  
Huiming Jin ◽  
...  

In this research, thermoplastic polyimide (TPI) were welding via friction stir spot welding (FSSW) in order to evaluate the feasibility of the technology. The welding tool with a tri-flute pin was used for keeping the welding effectiveness. The effect of the rotation speed and dwell time on the microstructure and shear strength was studied. The results shows that the number of gap defects between the shoulder affect zone and the pin affect zone decreased with the increase of the rotation speed. The boundary of the shoulder affect zone and the pin affect zone was no clear when increasing the dwell time from 10 s to 20 s. Long dwell time could increase the mixing time and reduce the materials viscosity, which made the structure was denser. The maximal shear strength was obtained 85.5% of the base materials. The differential scanning calorimetry (DSC) results indicated that the melting behaviour of different regions was no obvious difference. It indicated that FSSW had a feasible and potential technology to join the high temperature resistant engineering plastics.


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