Corrosion Characterization of Resistance Spot Welded Aluminum and Steel Couple

2019 ◽  
Author(s):  
Surender Maddela ◽  
Blair E. Carlson
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
Galvanic Corrosion ◽  
Corrosion Testing ◽  
Lap Shear Strength ◽  
Resistance Spot ◽  
Lap Shear ◽  
Cyclic Corrosion ◽  
Steel Substrates ◽  
Spot Welded

Abstract The corrosion resistance of resistance spot welded (RSW) Al-steel couples of varying combinations of 6016-T4 aluminum alloys and steel substrates, including with and without adhesive at the faying interface has been successfully evaluated, and compared to corresponding self-pierce riveted (SPR) couples. The corrosion resistance of resistance spot welded Al-steel couples has performed well in cyclic corrosion testing (GMW 17026) and the results are comparable to or better than that of self-pierce riveted couples. SPR couples are more susceptible to galvanic corrosion than resistance spot-welded couples based upon experimentally measured electrochemical potentials from actual joints. The presence of adhesive acts significantly to reduce galvanic corrosion between aluminum alloy and steel substrates, and moreover tensile lap-shear strength significantly increased with structural adhesive for both RSW and SPR joining systems. However, despite the presence of adhesive the lap-shear strength was reduced by more than 50% after cyclic corrosion testing to strength levels comparable to the lap-shear strength of couples having no adhesive and tested in ambient conditions.

Corrosion Characterization of Resistance Spot-Welded Aluminum and Steel Couple

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Surender Maddela ◽  
Blair E. Carlson
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
Galvanic Corrosion ◽  
Corrosion Testing ◽  
Ambient Conditions ◽  
Lap Shear Strength ◽  
Resistance Spot ◽  
Lap Shear ◽  
Cyclic Corrosion ◽  
Spot Welded

Abstract The corrosion resistance of resistance spot-welded (RSW) Al–steel couples of varying combinations of 6016-T4 aluminum alloys and steel substrates, including with and without adhesive at the faying interface, has been successfully evaluated and compared with corresponding self-pierce riveted (SPR) couples. The corrosion resistance of resistance spot-welded Al–steel couples has performed well in cyclic corrosion testing (GMW 17026), and the results are comparable to or better than that of self-pierce riveted couples. SPR couples are more susceptible to galvanic corrosion than resistance spot-welded couples based upon experimentally measured electrochemical potentials from actual joints. The presence of adhesive acts significantly to reduce galvanic corrosion between aluminum alloy and stleel substrates, and moreover, tensile lap-shear strength significantly increased with structural adhesive for both RSW and SPR joining systems. However, despite the presence of adhesive, the lap-shear strength was reduced by more than 50% after cyclic corrosion testing to strength levels comparable to the lap-shear strength of couples having no adhesive and tested in ambient conditions.

Lap shear strength and fatigue life of friction stir spot welded AZ31 magnesium and 5754 aluminum alloys

2012 ◽  
Vol 556 ◽  
pp. 500-509 ◽  
Author(s):  
S.H. Chowdhury ◽  
D.L. Chen ◽  
S.D. Bhole ◽  
X. Cao ◽  
P. Wanjara
Keyword(s):  
Shear Strength ◽  
Fatigue Life ◽  
Aluminum Alloys ◽  
Lap Shear Strength ◽  
Friction Stir ◽  
Lap Shear ◽  
Spot Welded

Mechanical properties of multiwall carbon nanotubes/unidirectional carbon fiber-reinforced epoxy hybrid nanocomposites in transverse and longitudinal fiber directions

2021 ◽  
pp. 096739112098651
Author(s):  
Saeedeh Saadatyar ◽  
Mohammad Hosain Beheshty ◽  
Razi Sahraeian
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Epoxy Resin ◽  
Interlaminar Shear Strength ◽  
Lap Shear Strength ◽  
Transverse Tensile ◽  
Lap Shear ◽  
Longitudinal Fiber ◽  
Interlaminar Shear ◽  
Multiwall Carbon

Unidirectional carbon fiber-reinforced epoxy (UCFRE) is suffering from weak transverse mechanical properties and through-thickness properties. The effect of different amount (0.1, 0.3 and 0.5 phr which is proportional to 0.09, 0.27 and 0.46 wt%, respectively) of multiwall carbon nanotube (MWCNT), on transverse tensile properties, flexural strength, fracture toughness in transverse and longitudinal fiber directions, interlaminar shear strength and lap shear strength of UCFRE has been investigated. Dicyandiamide was used as a thermal curing agent of epoxy resin. MWCNT was dispersed in the epoxy resin by ultrasonic instrument and their dispersion state was investigated by scanning electron microscopy (SEM). The curing behavior of epoxy resin and its nanocomposites was assessed by differential scanning calorimetry. Results show that transverse tensile strength, modulus and strain-at-break were increased by 28.5%, 25% and 14%, respectively by adding 0.1 phr of MWCNT. Longitudinal flexural properties of UCFRE was not changed by adding different amount of MWCNT. Although longitudinal flexural strength was increased by 5% by adding 0.1 phr of MWCNT. Fracture toughness in transverse and longitudinal fiber directions was increased by 39% and 9%, respectively at 0.3 phr of MWCNT. Results also show that interlaminar shear strength and lap shear strength were increased at 0.3 phr of MWCNT by 8% and 5%, respectively. These increases in mechanical properties were due to the good adhesion of fibers to the matrix, interlocking and toughening action of MWCNT as revealed by SEM.

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