Influence of Heat Treatment on Properties of 2219AA-T6 FSW Joints

2014 ◽  
Vol 590 ◽  
pp. 187-191 ◽  
Author(s):  
Chuan Hong Luo ◽  
Wei Ping Peng ◽  
Ting Chen ◽  
Fei Bo Dong

The joint of 2219-T6 aluminum alloy plate was obtained by friction stir welding, and the microstructures and mechanical properties of the joint were investigated. The causes of the weakened joint strength in friction stir welding were analyzed and summarized correspondingly. The tensile properties show that the transverse tensile strength of the joint can reach about 70% of the base metal. Through the heat treatment of recrystallization with high temperature and at short time, the joint can restore the ductility and eliminate the softening, which will improve the performance in mechanical intensity of the joint.

2014 ◽  
Vol 590 ◽  
pp. 249-253 ◽  
Author(s):  
Chuan Hong Luo ◽  
Ting Chen ◽  
Wei Ping Peng

The joint of 2219-T6 aluminum alloy plate was obtained by friction stir welding, and the microstructures and mechanical properties of the joint were investigated. The causes of the weakened joint strength in friction stir welding were analyzed and summarized correspondingly. The tensile properties show that the transverse tensile strength of the joint can reach about 70% of the base metal and the elongation can reach about 7%. The main reason of the weakened strength is due to the plastic damage of metal, followed by the defects generated in the nugget zone and the growth of θ phase in the heat affected zone.


Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1607
Author(s):  
Amir Hossein Baghdadi ◽  
Zainuddin Sajuri ◽  
Mohd Zaidi Omar ◽  
Armin Rajabi

Friction stir welding (FSW) is an alternative method to join aluminum (Al) alloys in a solid-state condition. However, the coarsening or dissolution of precipitation hardening phases in the welding zone causes strength reduction or softening behavior in the welded area of age-hardened Al alloys. Therefore, this research aimed to improve the mechanical properties of an FSW Al–Mg–Si alloy via post-weld heat treatment (PWHT) and the possibility of controlling the abnormal grain growth (AGG) using different welding parameters. FSW was performed with different rotational and travel speeds, and T6 heat treatment was carried out on the FSW samples as the PWHT. The results showed a decrease in the strength of the FSW samples compared with that of the base material (BM) due to the dissolution of precipitation hardening particles in the heat-affected zone. However, the emergence of AGG in the microstructure after the T6-PWHT was identified as the potential event in the microstructure of the PWHT samples. It is found that the AGG of the microstructure in similar joints of Al6061(T6) was governed by the welding parameters. The results proved that PWHT was able to increase the tensile properties of the welded samples to values comparable to that of Al6061(T6)-BM. The increased mechanical properties of the FSW joints were attributed to a proper PWHT that resulted in a homogeneous distribution of the precipitation hardening phases in the welding zones.


2020 ◽  
Vol 11 (6) ◽  
pp. 769-782 ◽  
Author(s):  
Nagabhushan Kumar Kadigithala ◽  
Vanitha C

PurposeThe main purpose of the present work is to evaluate, the microstructural and mechanical properties of friction stir welded plates of AZ91D magnesium alloy with 3 mm thickness, and to determine the optimum range of welding conditions.Design/methodology/approachMicrostructure and fractographic studies were carried out using scanning electron microscopy (SEM). Vickers micro hardness test was performed to evaluate the hardness profile in the region of the weld area. The phases in the material were confirmed by X-Ray diffraction (XRD) analysis. Transverse tensile tests were conducted using universal testing machine (UTM) to examine the joint strength of the weldments at different parameters.FindingsMetallographic studies revealed that each zone shown different lineaments depending on the mechanical and thermal conditions. Significant improvement in the hardness was observed between the base material and weldments. Transverse tensile test results of weldments had shown almost similar strength that of base material regardless of welding speed. Fractographic examination indicated that the welded specimens failed due to brittle mode fracture. Through these studies it was confirmed that friction stir welding (FSW) can be used for the welding of AZ91D magnesium alloy.Research limitations/implicationsIn the present study, the welding speed varied from 25 mm/min to 75 mm/min, tilt angle varied from 1.5° to 2.5° and constant rotational speed of 500 rpm.Practical implicationsMagnesium and aluminum based alloys which are having high strength and low density, used in automotive and aerospace applications can be successfully joined using FSW technique. The fusion welding defects can be eliminated by adopting this technique.Originality/valueLimited work had been carried out on the FSW of magnesium based alloys over aluminum based alloys. Furthermore, this paper analyses the influence of welding parameters over the microstructural and mechanical properties.


Author(s):  
J.C. Verduzco Huarez ◽  
R. Garcia Hernandez ◽  
G. M. Dominguez Almaraz ◽  
J.J. Villalón López

This research work focuses on the study of the improvement of mechanical properties, specifically the tensile strength of 6061-T6 aluminum alloy on prismatic specimens with 9.5 mm thickness that has been subjected to friction stir welding process and two heat treatments; solubilized and aging before or after the welding process. Three cases studied and evaluated were, welding of the base material without heat treatment (BMW), solubilized heat treatment and partial aging of the base material before welding (HTBW), and heat treatment of solubilized and aging of the base material after welding (HTAW). The obtained results show an increase of about 10% (20 MPa) of tensile strength for the HTBW process, compared to BMW case. In addition, for the case of HTAW, the obtained tensile resistance presents a joint efficiency of 96%, which is close to the tensile strength of the base material (»310 MPa).


2012 ◽  
Vol 602-604 ◽  
pp. 608-611
Author(s):  
Di Qiu He ◽  
Rui Lin Lai ◽  
Shao Hua Xu ◽  
Kun Yu Yang ◽  
Shao Yong Ye ◽  
...  

In this study, Cu-Cr-Zr alloy joints are successfully fabricated by friction stir welding (FSW). Defect-free weld are produced on 12mm thick Cu-Cr-Zr alloy plate useing a non-consumable tool with a specially designed and shoulder with a constant rotation speed and a fixed traverse speed. The effect of friction stir welding (FSW) on the microstructure and mechanical properties of Cu-Cr-Zr alloy joints are investigated in details: The joints showed the presence of various zones such as nugget zone (NZ) and thermo-mechanically affected zone (TMAZ) and base metal (BM), the microhardness and the tensile strength of welded joints are lower than that of the base material.


2010 ◽  
Vol 667-669 ◽  
pp. 505-510
Author(s):  
Ilya Nikulin ◽  
Alla Kipelova ◽  
Sergey Malopheyev ◽  
Rustam Kaibyshev

Friction stir welding (FSW) was used to join the submicrocrystalline (SMC) grained Al-Cu-Mg-Ag sheets produced by equal channel angular pressing (ECAP) followed by hot rolling (HR). The effect of SPD and FSW on the microstructure and mechanical properties in the zone of base metal, as well as in the stirred zone (SZ) were examined. In addition, effect of standard heat treatment on microstructure and mechanical properties in these zones was considered. A refined microstructure with an average grain size of ~ 0.6 m and a portion of high-angle grain boundaries (HAGBs) of ~0.67 was produced in sheets by ECAP followed by HR at 250°C. The microcrystalline grained structure with average grain size of ~2.3 mm was found in joint weld. The moderate mechanical properties were revealed in SMC sheets and joint welds. Heat treatment considerably increases strength of the base metal as well as the joint welds. The higher strength of the alloy after T6 temper is attributed to the dense precipitations of  dispersoids having plate-like shape which are uniformly distributed within aluminum matrix. It was observed that FSW can produce full strength weld both in the tempered and in the un-tempered conditions.


2011 ◽  
Vol 117-119 ◽  
pp. 1621-1624 ◽  
Author(s):  
Zheng Hua Guo ◽  
Gang Yao Zhao ◽  
Li Ming Ke ◽  
Li Xing ◽  
Shun Feng Zhu

A 3D elastic-plastic and coupled thermo-mechanical FE model for friction stir welding(FSW) of 7075 aluminum alloy plate was developed based on the dynamic explicit code ABAQUS/explicit, then the FSW process of 7075 aluminum alloy plate was simulated and the materials flow behavior was analyzed. The results show that in the horizontal direction of the plate, two patterns of materials migration are produced: (1) the material rotates with the tool and finally deposits the tentative cavity behind the pin; (2) the material transfers in the mode of laminar flow. Furthermore, the streamlines of material in advanced side (AS) are bent along the reverse welding direction. After bypassing the pin, the material of retreating side (RS) moves backward it, and extends to AS.


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