Hook formation and mechanical properties in AZ31 friction stir spot welds

Yin, Yue; Sun, Ning; North, T. H.; Hu, Shengsun

doi:10.1016/j.jmatprotec.2010.07.029

Cited by 109 publications

(43 citation statements)

References 19 publications

(26 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4b. Similar results were reported by Badarinarayan et al [22] and Yin et al [23]. Furthermore, the formation of the kiss bonding is owing to the insufficient flow resulted from the incomplete stirring of the pin.…”

Section: Methodssupporting

confidence: 87%

Formation characteristic, microstructure, and mechanical performances of aluminum-based components by friction stir additive manufacturing

Mao

Huang

et al. 2015

Int J Adv Manuf Technol

View full text Add to dashboard Cite

In this study, a new solid-state technique of friction stir additive manufacturing (FSAM) based on friction stir welding (FSW) principle was used to build successfully a multilayered stack of an Al-based component. The results show that a hook stretches into the nugget zone on advancing side, while it moves upwards to the periphery on retreating side for a single-level welding. With manufacturing the second layer, the hooks bend outward significantly attributing to the extrusion of above plastic material, which can avoid the hook to stretch into the stirred zone. A transition zone (TZ) is also formed near the interface between two layers. In addition, fine equiaxed grains are observed due to the dynamic recrystallization in the whole. However, a difference in grain size still exists through the build direction and in the TZ is forming coarse band grains. A similar change occurs in the precipitate morphology, size, and distribution. Form the top to the bottom, the microhardness changes dramatically, and a maximum 115 HV at the top is obtained. The tensile strength of all the slices increases and the elongation decreases slightly in comparison of Al substrate, and the slice top has the highest mechanical properties, which is attributed to fine grains and desirable precipitate characterization.

show abstract

Section: Methodssupporting

confidence: 87%

Formation characteristic, microstructure, and mechanical performances of aluminum-based components by friction stir additive manufacturing

Mao

Huang

et al. 2015

Int J Adv Manuf Technol

View full text Add to dashboard Cite

show abstract

“…The SZ is characterized by fine grain structure due to dynamic recrystallization [4,9,16,21]. This region underwent severe plastic deformation due to the sleeve and pin movement and was exposed to high temperature, as illustrated in Figure 6c.…”

Section: Microstructure Evaluationmentioning

confidence: 99%

“…An additional microstructure feature that is important for the mechanical performance in the similar joint configuration is the hook [7,16,21]. The hook is formed at the transition between the unwelded sheet interface and the metallurgically bonded region.…”

Section: Microstructure Evaluationmentioning

confidence: 99%

Process optimization and microstructure analysis in refill friction stir spot welding of 3-mm-thick Al-Mg-Si aluminum alloy

Santana

Suhuddin

Ölscher

et al. 2017

Int J Adv Manuf Technol

View full text Add to dashboard Cite

Novel ultra-high-strength aluminum alloys provide enormous lightweighting potential for modern car body design. However, joining such alloys can be challenging. Refill friction stir spot welding is a solid state joining process that provides fundamental advantages compared to conventional joining technologies when welding aluminum alloys. This work presents refill friction stirspot welding for joining3-mm-thick Al-Mg-Si alloys. The welded joints have been optimized for shear load condition by the design of experiment and analysis of variance. The results show that it is possible to obtain welds of relatively thick Al-Mg-Si alloys with good mechanical properties. Microstructure analyses show that rotational speed and plunge depth play important rolesin the bonded width and hook height, which affect the mechanical performance of the joint. KeywordsRefill friction stir spot welding; Aluminum alloy; Design of experiments; Response surface methodology; hook; shear layer Highlights • Refill friction stir spot welding of 3-mm-thick Al-Mg-Si alloy single-lap joints was demonstrated • The influence of joining parameters on joint mechanical performance was determined.• A mathematical model for estimating lap shear strength was successfully established.

show abstract

“…In [16] it was observed that the shear resistance of the weld increases for decreasing tool rotating speed and for increasing tool plunge rate. Besides, in [15] it was stated that the lap shear strength of the joints can be improved by increasing the dwell time or in general by optimizing this parameter [17]. On the contrary, in other researches [18] it was observed that the resistance of the joints decreases for decreasing values of the tool rotating speed.…”

Section: Introductionmentioning

confidence: 98%

FEM model for the thermo-mechanical characterization of friction stir spot welded joints

D’Urso

Giardini

2015

Int J Mater Form

View full text Add to dashboard Cite

A simulation study of the Friction Stir Spot Welding process for the lap-joining of thin aluminum sheets was carried out using the FEM code DEFORM 2D. The special feature of the developed FEM model is a 2D approach used for the simulation of a 3D problem, in order to guarantee a very simple and practical solution able to achieve results in a very short time. A set of experiments was performed by means of a CNC machine tool and FSSW lap joints on AA6060-T6 aluminum alloy plates were obtained. The experimental results were used as reference cases for the model validation. A set of tests was carried out by varying the process parameters, namely rotational speed, axial feed rate and plunging depth. Axial welding forces and temperature distribution in the joining region were recorded during the tests and their dependency from the welding parameters was studied. Shear tests were also performed to evaluate the quality of the joints as function of the welding conditions. A satisfactory matching between numerical and experimental data was found (average errors ranging around 10 %), confirming the good predictive ability of the FEM model. The FEM simulations were finally used for the prediction of the joint shear resistance.

show abstract

Hook formation and mechanical properties in AZ31 friction stir spot welds

Cited by 109 publications

References 19 publications

Formation characteristic, microstructure, and mechanical performances of aluminum-based components by friction stir additive manufacturing

Formation characteristic, microstructure, and mechanical performances of aluminum-based components by friction stir additive manufacturing

Process optimization and microstructure analysis in refill friction stir spot welding of 3-mm-thick Al-Mg-Si aluminum alloy

FEM model for the thermo-mechanical characterization of friction stir spot welded joints

Contact Info

Product

Resources

About