Effects of Welding Wire Composition on Microstructure and Mechanical Properties of Welded Joint in Al-Mg-Si Alloy

2022 ◽  
Vol 905 ◽  
pp. 44-50
Author(s):  
Li Wang ◽  
Ya Ya Zheng ◽  
Shi Hu Hu
Keyword(s):  
Mechanical Properties ◽  
Fusion Zone ◽  
Heat Affected Zone ◽  
Welded Joint ◽  
Weld Zone ◽  
Xrd Analysis ◽  
Metallographic Analysis ◽  
Strengthening Effect ◽  
Welding Wire ◽  
Microstructure And Mechanical Properties

The effects of welding wire composition on microstructure and mechanical properties of welded joint in Al-Mg-Si alloy were studied by electrochemical test, X-ray diffraction (XRD) analysis and metallographic analysis. The results show that the weld zone is composed of coarse columnar dendrites and fine equated grains. Recrystallized grains are observed in the fusion zone, and the microstructure in the heat affected zone is coarsened by welding heat. The hardness curve of welded joint is like W-shaped, the highest hardness point appears near the fusion zone, and the lowest hardness point is in the heat affected zone. The main second phases of welded joints are: matrix α-Al, Mg2Si, AlMnSi, elemental Si and SiO2. The addition of rare earth in welding wire can refine the grain in weld zone obviously, produce fine grain strengthening effect, and improve the electrochemical performance of weld.

Microstructure and Mechanical Properties of GMAW Welded Joints Er-Containing Aluminum Alloy

2020 ◽  
Vol 993 ◽  
pp. 92-99
Author(s):  
Hao Zhen Guo ◽  
Li Cui ◽  
Hui Huang ◽  
Xiao Guo ◽  
Ding Yong He
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Penetration Depth ◽  
Welded Joint ◽  
Weld Zone ◽  
Welding Process ◽  
Welding Current ◽  
Depth Range ◽  
Arc Voltage ◽  
Microstructure And Mechanical Properties

This present work explored the welding process of gas metal arc welding for 4mm 5E61 Er-containing aluminum alloy, and then analyzed the microstructure and mechanical properties of the welded joint. The results demonstrated that when the welding current was 160A-220A, the welded joint penetration depth range was 5.75mm to 6.72mm, the melting width ranging from 9.68mm to 11.61mm. When the arc voltage increased from 17.5V to 22.5V, the penetration depth of the welded joint reduced from 6.95mm to 5.57mm, and the melting width ranged from 6.64mm to 11.86mm. When the welding current was 170A, the arc voltage was 17.5V, and the welding speed was 10mm/s. In the third case, a fully penetrated welded joint can be obtained and the joint strength was the highest value. The yield strength reached 192 MPa, the tensile strength can be 301 MPa, and the fracture location occurred in the HAZ. The weld zone of the welded joint mainly consist of the equiaxed dendrites size of 50 μm. The micro-hardness of the weld zone was lower than that of the base metal, and there was no obvious softening phenomenon in the heat affected zone.

Influence of filler material on the microstructure, mechanical properties, and residual stresses in tungsten inert gas welded Ti-5Al-2.5Sn alloy joints

2021 ◽  
pp. 146442072110124
Author(s):  
Asim Iltaf ◽  
Fahd Nawaz Khan ◽  
Tauheed Shehbaz ◽  
Massab Junaid
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Fusion Zone ◽  
Welded Joint ◽  
Weld Zone ◽  
Martensitic Transformations ◽  
Inert Gas ◽  
Physical Chemical ◽  
Pile Up ◽  
Compressive Residual Stresses

The microstructure and defects in the weld zone affect the weldment characteristics. One way to improve the microstructure and reduce the defects in the weld zone is by using a filler during welding which influences the physical, chemical, and mechanical properties of the manufactured component. In the present study, tungsten inert gas (TIG) was used to weld Ti-5Al-2.5Sn alloy using different titanium alloy fillers; Ti-6Al-4V, Ti-5Al-2.5Sn, and autogenous weldments were also produced. The welded joints were characterized in terms of their microstructure, mechanical properties, and residual stresses in its various regions. The weldment with Ti-6Al-4V as filler exhibited a higher proportion of α′ martensite in fusion zone, as compared to the welded joint with Ti-5Al-2.5Sn alloy as filler, owing to the higher proportions of β stabilizers present in Ti-6Al-4V alloy. The α’ martensite was present in basketweave and acicular morphology in all the weldments, with and without fillers. Ti-6Al-4V filler welded joint showed higher tensile strength (approximately 1144 MPa) and relatively higher hardness than Ti-5Al-2.5Sn filler welded joint (approximately 1027 MPa) and autogenous weldment (approximately 770 MPa), due to increased amount of martensite in its fusion zone. As compared to the weldment produced with Ti-5Al-2.5Sn filler, the welded joint produced without filler and with Ti-6Al-4V as a filler had more compressive residual stresses at surface (approximately 25% higher), leading to less amount of pile up after nanoindentation. This was attributed to the generation of compressive strains due to martensitic transformations in the fusion zone of both these weldments.

Effect of Metal Inert Gas Welding on Microstructure and Mechanical Properties of Al-Zn-Mg Alloy

2011 ◽  
Vol 418-420 ◽  
pp. 1396-1399
Author(s):  
Feng Wang ◽  
Bai Qing Xiong ◽  
Yon Gan Zhang ◽  
Hong Wei Liu ◽  
Zhi Hui Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fusion Zone ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Tensile Tests ◽  
Eutectic Structure ◽  
Optical Microscope ◽  
Inert Gas ◽  
Transverse Tensile ◽  
Microstructure And Mechanical Properties

Abstract. The microstructure and mechanical properties of a metal inert gas welds in a medium strength Al-4Zn-1Mg alloy were characterized by optical microscope (OM), scanning electron microscope (SEM) and tensile tests. It is found that the joint of the alloy contained three distinctive regions, i.e. fusion zone, heat affected zone and base metal region. Extensive microhardness measurements were conducted in the weld regions of the nuggets exhibited a hardness loss in the fusion zone due to the loss of strengthening phases. Microstructural examination of the joints revealed typical eutectic structure was appeared in the heat-affected zone. Tensile properties of the joints were obtained by testing flat transverse tensile specimens, and the results indicated that tensile strength of these welds approached 83.3~84.2% of the base metal.

scholarly journals Microstructure and mechanical properties of GTAW welded joints of AA6105 aluminum alloy

2016 ◽  
Vol 25 (43) ◽  
pp. 7-19 ◽  
Author(s):  
Minerva Dorta-Almenara ◽  
María Cristina Capace
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Fusion Zone ◽  
Heat Affected Zone ◽  
Welding Speed ◽  
Heat Input ◽  
Cold Work ◽  
Dendritic Morphology ◽  
Welding Parameters ◽  
Microstructure And Mechanical Properties

Gas Tungsten Arc Welding (GTAW) is one of the most used methods to weld aluminum. This work investigates the influence of welding parameters on the microstructure and mechanical properties of GTAW welded AA6105 aluminum alloy joints. AA6105 alloy plates with different percent values of cold work were joined by GTAW, using various combinations of welding current and speed. The fusion zone, in which the effects of cold work have disappeared, and the heat affected zone of the welded samples were examined under optical and scanning electron microscopes, additionally, mechanical tests and measures of Vickers microhardness were performed. Results showed dendritic morphology with solute micro- and macrosegregation in the fusion zone, which is favored by the constitutional supercooling when heat input increases. When heat input increased and welding speed increased or remained constant, greater segregation was obtained, whereas welding speed decrease produced a coarser microstructure. In the heat affected zone recrystallization, dissolution, and coarsening of precipitates occurred, which led to variations in hardness and strength.

scholarly journals Influence of Post Weld Heat Treatment on the Grain Size, and Mechanical Properties of the Alloy-800H Rotary Friction Weld Joints

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4366
Author(s):  
Saqib Anwar ◽  
Ateekh Ur Rehman ◽  
Yusuf Usmani ◽  
Ali M. Al-Samhan
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Heat Affected Zone ◽  
Tensile Testing ◽  
Weld Zone ◽  
Alloy 800H ◽  
Weld Joints ◽  
Heat Treated ◽  
Friction Weld

This study evaluated the microstructure, grain size, and mechanical properties of the alloy 800H rotary friction welds in as-welded and post-weld heat-treated conditions. The standards for the alloy 800H not only specify the composition and mechanical properties but also the minimum grain sizes. This is because these alloys are mostly used in creep resisting applications. The dynamic recrystallization of the highly strained and plasticized material during friction welding resulted in the fine grain structure (20 ± 2 µm) in the weld zone. However, a small increase in grain size was observed in the heat-affected zone of the weldment with a slight decrease in hardness compared to the base metal. Post-weld solution heat treatment (PWHT) of the friction weld joints increased the grain size (42 ± 4 µm) in the weld zone. Both as-welded and post-weld solution heat-treated friction weld joints failed in the heat-affected zone during the room temperature tensile testing and showed a lower yield strength and ultimate tensile strength than the base metal. A fracture analysis of the failed tensile samples revealed ductile fracture features. However, in high-temperature tensile testing, post-weld solution heat-treated joints exhibited superior elongation and strength compared to the as-welded joints due to the increase in the grain size of the weld metal. It was demonstrated in this study that the minimum grain size requirement of the alloy 800H friction weld joints could be successfully met by PWHT with improved strength and elongation, especially at high temperatures.

scholarly journals Microstructure and Mechanical Properties of Heat-Affected Zone of Repeated Welding AISI 304N Austenitic Stainless Steel by Gleeble Simulator

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 773
Author(s):  
Y.H. Guo ◽  
Li Lin ◽  
Donghui Zhang ◽  
Lili Liu ◽  
M.K. Lei
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Energy ◽  
Heat Affected Zone ◽  
Ferrite Content ◽  
Equipment Safety ◽  
Microstructure And Mechanical Properties ◽  
Δ Ferrite ◽  
The Impact

Heat-affected zone (HAZ) of welding joints critical to the equipment safety service are commonly repeatedly welded in industries. Thus, the effects of repeated welding up to six times on the microstructure and mechanical properties of HAZ for AISI 304N austenitic stainless steel specimens were investigated by a Gleeble simulator. The temperature field of HAZ was measured by in situ thermocouples. The as-welded and one to five times repeated welding were assigned as-welded (AW) and repeated welding 1–5 times (RW1–RW5), respectively. The austenitic matrices with the δ-ferrite were observed in all specimens by the metallography. The δ-ferrite content was also determined using magnetic and metallography methods. The δ-ferrite had a lathy structure with a content of 0.69–3.13 vol.%. The austenitic grains were equiaxial with an average size of 41.4–47.3 μm. The ultimate tensile strength (UTS) and yield strength (YS) mainly depended on the δ-ferrite content; otherwise, the impact energy mainly depended on both the austenitic grain size and the δ-ferrite content. The UTS of the RW1–RW3 specimens was above 550 MPa following the American Society of Mechanical Engineers (ASME) standard. The impact energy of all specimens was higher than that in ASME standard at about 56 J. The repeated welding up to three times could still meet the requirements for strength and toughness of welding specifications.

Microstructure and mechanical properties of friction stir welded joint of TRIP steel

2020 ◽  
Vol 56 ◽  
pp. 623-634 ◽  
Author(s):  
Wen Wang ◽  
Shengyi Zhang ◽  
Ke Qiao ◽  
Kuaishe Wang ◽  
Pai Peng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Trip Steel ◽  
Welded Joint ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties

scholarly journals Microstructures and Mechanical Properties of a Laser-Welded Joint of Ti3Al-Nb Alloy Using Pure Nb Filler Metal

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 785 ◽  
Author(s):  
Lin Wang ◽  
Daqian Sun ◽  
Hongmei Li ◽  
Xiaoyan Gu ◽  
Chengjie Shen
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Base Metal ◽  
Joint Strength ◽  
Filler Metal ◽  
Weld Zone ◽  
Strengthening Effect ◽  
Joint Properties ◽  
Microstructures And Mechanical Properties ◽  
Welding System

Ti3Al-Nb alloy (Ti-24Al-15Nb) was welded by a pulsed laser welding system without and with pure Nb filler metal. The results indicated that pure Nb filler metal had profound effects on the microstructures and mechanical properties of the laser-welded joints. The joint without filler metal consisted of the weld zone (α’2 + B2), heat affected zone HAZ1 (α2 + B2), HAZ2 (α2 + O + B2) and base metal (α2 + O + B2), and gas pores were generated in the weld resulting in the deterioration of the joint strength (330 MPa) and elongation (1.9%). When the Nb filler metal was used, the weld microstructure (NbTi solid solution + O + B2) was obtained, and the joint properties were significantly improved, which was associated with the strengthening effect of the NbTi solid solution, O phase precipitation and the slip transmission between O and B2 phases, and the restraining of the formation of martensite (α’2) and gas pores in the weld. The strength (724 MPa) and elongation (5.1%) of the joint increased by 119.4% and 168.4% compared with those of the joint without filler metal, and the joint strength was able to reach 81.7% of the base metal strength (886 MPa). It is favorable to use pure Nb filler metal for improving the mechanical properties of laser-welded Ti3Al-Nb alloy joints.

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