Three-Sheet Spot Welds of 5052 Aluminum Alloy: Weld Growth and Failure Behavior

2015 ◽  
Vol 782 ◽  
pp. 158-163 ◽  
Author(s):  
Fu Yu Yan ◽  
Zhen Luo ◽  
Yuh J. Chao ◽  
San San Ao ◽  
Yang Li ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Failure Modes ◽  
Peltier Effect ◽  
Failure Behavior ◽  
Spot Welds ◽  
Resistance Spot ◽  
Pull Out ◽  
Resistance Spot Welds ◽  
Nugget Formation ◽  
Alloy Weld

Resistance spot welding is used extensively in auto industry. Every commercial vehicle has 4000-5000 spot welds. The weld ability, performance, and reliability are therefore important issues in design. In this paper, we studied weld nugget formation and failure behavior of three-sheet 5052 aluminum alloy resistance spot welds. The Peltier effect between the Cu-Al (the electrode and the Al worksheet) to the nugget formation was noticed. The mechanical strength and fracture mode of the weld nuggets at the upper and lower interfaces were studied using tensile shear specimen configuration. Three failure modes were identified, namely, interfacial, mixed, and pull-out. The critical welding time and critical nugget diameter corresponding to the transitions of these modes were investigated. Finally, an empirical failure load formula for three-sheet weld similar to two-sheet spot weld was developed.

scholarly journals Effect of weld nugget size on failure mode and mechanical properties of microscale resistance spot welds on Ti–1Al–1Mn ultrathin foils

2018 ◽  
Vol 10 (7) ◽  
pp. 168781401878528 ◽  
Author(s):  
Feng Chen ◽  
Shiding Sun ◽  
Zhenwu Ma ◽  
GQ Tong ◽  
Xiang Huang
Keyword(s):  
Mechanical Properties ◽  
Failure Mode ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Weld Nugget ◽  
Interfacial Failure ◽  
Spot Welds ◽  
Resistance Spot ◽  
Resistance Spot Welds ◽  
Pullout Failure

We use tensile–shear tests to investigate the failure modes of Ti–1Al–1Mn microscale resistance spot welds and to determine how the failure mode affects the microstructure, microhardness profile, and mechanical performance. Two different failure modes were revealed: interfacial failure mode and pullout failure mode. The welds that fail by pullout failure mode have much better mechanical properties than those that fail by interfacial failure mode. The results show that weld nugget size is also a principal factor that determines the failure mode of microscale resistance spot welds. A minimum weld nugget size exists above which all specimens fail by pullout failure mode. However, the critical weld nugget sizes calculated using the existing recommendations are not consistent with the present experimental results. We propose instead a modified model based on distortion energy theory to ensure pullout failure. Calculating the critical weld nugget size using this model provides results that are consistent with the experimental data to high accuracy.

Effect of external magnetic field on resistance spot welds of aluminum alloy

2014 ◽  
Vol 56 ◽  
pp. 1025-1033 ◽  
Author(s):  
Yang Li ◽  
Zhen Luo ◽  
Fuyu Yan ◽  
Rui Duan ◽  
Qi Yao
Keyword(s):  
Magnetic Field ◽  
Aluminum Alloy ◽  
External Magnetic Field ◽  
Spot Welds ◽  
Resistance Spot ◽  
Resistance Spot Welds

scholarly journals Segregations in nugget of the aluminum alloy resistance spot welds.

1987 ◽  
Vol 37 (6) ◽  
pp. 405-412
Author(s):  
Yoichi TOMII ◽  
Masao KIKUCHI ◽  
Masahide WATANABE ◽  
Masao MIZUNO
Keyword(s):  
Aluminum Alloy ◽  
Spot Welds ◽  
Resistance Spot ◽  
Resistance Spot Welds

Influence of Paint Baking on the Energy Absorption and Failure Mode of Resistance Spot Welds in TRIP1180 Steel

2021 ◽  
Vol 143 (9) ◽  
Author(s):  
D. V. Marshall ◽  
D. Bhattacharya ◽  
J. G. Speer
Keyword(s):  
Energy Absorption ◽  
Failure Mode ◽  
Low Energy ◽  
Interfacial Failure ◽  
Spot Welds ◽  
Resistance Spot ◽  
Pull Out ◽  
Resistance Spot Welds ◽  
Tension Testing ◽  
Cross Tension

Abstract Resistance spot welds (RSWs) in advanced high strength steels frequently exhibit interfacial failure during cross-tension testing: a mode of fracture associated with low-energy absorption. Automotive assembly lines include a paint application and baking cycle after the vehicle assembly and joining processes to cure paint and any adhesives used for assembly. In this article, the effects of a typical baking cycle: 180 °C for 20 min, on the failure mode and energy absorption during cross-tension testing of RSWs made in a TRIP1180 steel are reported. Further, short-time baking cycles of 30 s, 90 s, and 4 min were employed to investigate how quickly these baking effects are activated. RSWs, which exhibited interfacial failure and a low-energy absorption of 30.9 J in the as-welded condition, saw a change in a failure mode to partial interfacial failure and a 260% increase in energy absorption after baking for 30 s. After baking for a longer time (4 min), welds failed by button pull-out and exhibited a 296% increase in energy absorption during cross-tension testing. Baking for the full 20 min resulted in no additional improvement than was observed in the 4 min condition. The mechanisms responsible for the majority of the improvement in weld performance during baking are found to be activated after only 30 s of baking.

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