Microstructure Characteristics and Properties of 1561 Aluminum Alloy Weldments Processed by Different MIG Welding

2017 ◽  
Vol 893 ◽  
pp. 163-168
Author(s):  
Shan Guo Han ◽  
Shi Da Zheng ◽  
De Tao Cai ◽  
Yao Yong Yi ◽  
Zi Yi Luo

The mechanical properties and microstructural features of 1561 aluminum alloy weldments processed by single-wire MIG welding and CMT TWIN welding are investigated. The microstructure and mechanical properties of welded joints were studied by nondestructive testing, metallurgical test, scanning electron microscopy test, fatigue and tensile test. It is revealed that the welding efficiency of CMT TWIN welding is more than six times as much as single-wire MIG welding. It can be easy to find weld zone (WZ), fusion line (FL), heat affected zone (HAZ) and base metal (BM) with different characteristics in the metallographic specimen. In weld zone, the particle phase sizes are smaller than that of base material, but the densities of particle phase are increased. The sample fatigue strength of CMT TWIN welding is higher than the singe-wire MIG welding. It is suggested that the CMT TWIN welding has several advantages compared with single-wire MIG welding.

2012 ◽  
Vol 525-526 ◽  
pp. 129-132 ◽  
Author(s):  
Yu E Ma ◽  
Zhen Qiang Zhao

Before friction stir welded integral panels are used in main aircraft structure, the corrosion behavior of welded joint need to be studied in detail. 2024 T3 samples were designed and welded by friction stir welding; the microstructure crossing the weld zone was observed by scanning electron microscopy (SEM), the feature of different zones (base material, thermo-mechanical affected zone, nugget) was seen; the corrosion testing in NaCl smoking box was carried out, and microstructure was observed after corrosion, localized corrosion predominantly occurs in the thermo-mechanical affected zone.


Author(s):  
Srinivasa Rao Pedapati ◽  
Dhanis Paramaguru ◽  
Mokhtar Awang

As compared to normal Friction Stir Welding (FSW) joints, the Underwater Friction Stir Welding (UFSW) has been reported to be obtainable in consideration of enhancement in mechanical properties. A 5052-Aluminum Alloy welded joints using UFSW method with plate thickness of 6 mm were investigated, in turn to interpret the fundamental justification for enhancement in mechanical properties of material through UFSW. Differences in microstructural features and mechanical properties of the joints were examined and discussed in detail. The results indicate that underwater FSW has reported lower hardness value in the HAZ and higher hardness value in the intermediate of stir zone (SZ). The average hardness value of underwater FSW increases about 53% greater than its base material (BM), while 21% greater than the normal FSW. The maximum micro-hardness value was three times greater than its base material (BM), and the mechanical properties of underwater FSW joint is increased compared to the normal FSW joint. Besides, the evaluated void-area fraction division in the SZ of underwater FSW joint was reduced and about one-third of the base material (BM). The approximately estimated average size of the voids in SZ of underwater FSW also was reduced to as low as 0.00073 mm2, when compared to normal FSW and BM with approximately estimated average voids size of 0.0024 mm2 and 0.0039 mm2, simultaneously.


2017 ◽  
Vol 754 ◽  
pp. 383-386
Author(s):  
Kee Nam Song

Different microstructures in the weld zone of a metal structure including a fusion zone and a heat affected zone, are formed as compared to the base material. Consequently, the mechanical properties in the weld zone are different from those in the base material to a certain degree owing to different microstructures and residual welding stresses. When a welded structure is loaded, the mechanical behavior of the welded structure might be different from the case of a structure with homogeneous mechanical properties. It is known that obtaining the mechanical properties in the weld is generally difficult owing to the narrow regions of the weld and interfaces. As an alternative way to obtain the weld mechanical properties, the weld mechanical properties of Alloy800HT, SUS316L, and Alloy617, were recently measured using an instrumented indentation technique, and the representative weld mechanical properties of these materials were estimated with a 95% lower confidence level for later structural analyses of the welded structures.


Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3672
Author(s):  
Guodong Liu ◽  
Qunying Yang ◽  
Yongshan Cheng

Because of the tensile strength decreasing of the friction stir welded wrought magnesium (Mg) alloy compared to the base material, the reasons for the failure of weld has been focused on. After the fracture in transverse tension, the crack went through the welded joint from the center of the weld to the transition zone between the thermal-mechanical affected zone and weld zone. In the present study, the microstructure characteristics and its effect on the facture in the triple junction region is investigated. Based on the metallography and the electron back-scattered diffraction (EBSD) technology, it was observed that a twin band extended from the triple junction region to the middle of weld. The profuse twinning in the twin band was considered to play an important role on the crack propagation from the stir zone edge to the crown zone.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 568
Author(s):  
Xinwei She ◽  
Xianquan Jiang ◽  
Bao Qi ◽  
Kang Chen

The effect of Er on microstructure and mechanical properties of the 5052 aluminum alloy with a big width-to-thickness ratio was investigated by a metallurgical microscope, scanning electron microscope and tensile testing machine. The results showed that the precipitates were slightly refined after Er addition and Al3Fe was transformed into Al6Fe and AlEr with/without a small amount of Fe or Si. The effect of Er on grain refinement was related to its content. When Er content was lower or higher than 0.4%, the grain would coarsen. Homogenization could refine the grain by controlling Er content and distribution in the Al matrix. Long time homogenization at high temperature would significantly reduce the strength of the 5052 aluminum alloy and 5052 aluminum alloys with low Er content, but help to improve the plasticity of those with high Er content. The ultimate tensile strength, yield strength and elongation of the as-cast 5052 aluminum alloy were 197 MPa, 117 MPa and 22.5% respectively. The strength was the highest, when Er content was 0.4 wt. % and the elongation was the best at 0.1 wt. % Er content.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Kee-nam Song ◽  
Sang-hoon Lee

Mechanical properties in a weld zone are different from those in the base material because of different microstructures. A spacer grid in PWR fuel is a structural component with an interconnected and welded array of slotted grid straps. Previous research on the strength analyses of the spacer grid was performed using base material properties owing to a lack of mechanical properties in the weld zone. In this study, based on the mechanical properties in the weld zone of the spacer grid recently obtained by an instrumented indentation technique, the strength analyses considering the mechanical properties in the weld zone were performed, and the analysis results were compared with the previous research.


Author(s):  
Malte L. Flachmann ◽  
Michael Seitz ◽  
Wilfried V. Liebig ◽  
Kay A. Weidenmann

AbstractComposite peening offers the opportunity to introduce ceramic blasting particles into metallic base material. By embedding Al2O3 particles, mechanical properties of aluminum can be improved. However, those surface modifications might negatively impact corrosion resistance and thus shorten the lifetime of components. This study analyzes corrosion properties of peened aluminum in chloride solution via immersion, scanning electron microscopy and polarization. The data of observed microstructures indicate that peening accelerates corrosion and that intergranular corrosion is the main force of degradation in contrast with pitting corrosion of monolithic aluminum.


2013 ◽  
Vol 772 ◽  
pp. 94-97 ◽  
Author(s):  
Wei Wu ◽  
Da Jun Chen

Microstructural and mechanical properties of friction stir welded 4mm7075-T6 aluminum alloy were investigated in this paper. The microstructures in WAZ,TMAZ and HAZ were analyzed. The results show that with the rotating speed at 1500 rpm and welding speed at 60mm/min, a defect-free welding joint was obtained. The tensile strength was 362 MPa, which is 65% of base metals; Weld nugget is composed of equiaxed grains; The lowest hardness between the TMAZ and HAZ of advancing side. The fractography revealed that samples failed in ductile mode and the strain fracture appears in advancing side of weld zone.


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