Revealing joining mechanism in refill friction stir spot welding of AZ31 magnesium alloy to galvanized DP600 steel

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).

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Friction Stir Spot Welding of Aluminum and Magnesium Alloy Sheets

10.4271/2005-01-1255 ◽

2005 ◽

Cited By ~ 25

Author(s):

P. Su ◽

A. Gerlich ◽

T.H. North

Keyword(s):

Magnesium Alloy ◽

Spot Welding ◽

Friction Stir Spot Welding ◽

Friction Stir

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Flat friction stir spot welding of AZ31B magnesium alloy using double side adjustable tools: microstructure and mechanical properties

Science and Technology of Welding & Joining ◽

10.1080/13621718.2020.1802896 ◽

2020 ◽

Vol 25 (8) ◽

pp. 644-652

Author(s):

Xiaopei Wang ◽

Yoshiaki Morisada ◽

Hidetoshi Fujii

Keyword(s):

Mechanical Properties ◽

Magnesium Alloy ◽

Spot Welding ◽

Friction Stir Spot Welding ◽

Az31b Magnesium Alloy ◽

Friction Stir ◽

Microstructure And Mechanical Properties

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Friction Stir Spot Welding of AZ31B Magnesium Alloy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.867.105 ◽

2017 ◽

Vol 867 ◽

pp. 105-111

Author(s):

S. Ramesh Babu ◽

M. Nithin ◽

S. Pavithran ◽

B Parameshwaran

Keyword(s):

Shear Strength ◽

Magnesium Alloy ◽

Rotational Speed ◽

Spot Welding ◽

Dwell Time ◽

Friction Stir Spot Welding ◽

Resistance Welding ◽

Hardness Distribution ◽

Tool Rotational Speed ◽

Friction Stir

The Electrical Resistance Welding (ERW) of Magnesium and Aluminium is more difficult than steel because the welding machines must provide high currents and exact pressures in order to provide the heat necessary to melt the magnesium for proper fusion at the interface in order to produce a sound weld. Further, resistance welding of magnesium requires a backup plate made of steel to conduct the heat to the workpiece material. To overcome this problem, Friction Stir Spot Welding (FSSW) has been developed. In this study, the hardness distribution and the tensile shear strength of FSSW welds in the AZ31B Magnesium alloy has been investigated and it has been found that tool rotational speed and dwell time plays a major role in determining the weld strength. From the experimental study, a tool rotational speed of 1100 rpm and dwell time of 20 s produced good shear strength of 2824 N and the corresponding grain size was 4.54 μm. This result is very well supported by microstructural examinations and hardness distribution studies.

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