Microstructure and Mechanical Properties of Laser Beam Welded AA7021 Aluminum Alloy

2014 ◽  
Vol 488-489 ◽  
pp. 106-110 ◽  
Author(s):  
Feng Wang ◽  
Bai Qing Xiong ◽  
Yong An Zhang ◽  
Hong Wei Liu ◽  
Zhi Hui Li ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Laser Beam ◽  
Fusion Zone ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Tensile Tests ◽  
Eutectic Structure ◽  
Optical Microscope ◽  
Transverse Tensile ◽  
Transmission Electron

In this study, a laser beam welds in a Al-Zn-Mg alloy were characterized by optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) 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. The fusion zone consists of small grains, whose size is heterogeneously distributed. 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 due to relative low cooling rate. Tensile properties of the joints were obtained by testing flat transverse tensile specimens, and the results indicated that tensile strength of these welds approached 76.8~77.3% of the base metal.

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 Measurement of the Interfacial Normal Strength in Single Fibre Transverse Tensile Tests

1997 ◽  
Vol 6 (1) ◽  
pp. 096369359700600
Author(s):  
P.F.M. Meurs ◽  
P.J.G. Schreurs ◽  
T. Peijs
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Numerical Simulations ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Single Fibre ◽  
Promising Tool ◽  
Transverse Tensile ◽  
Normal Strength ◽  
Scanning Electron

A technique is presented which can be used to measure the interfacial normal strength in transversely loaded composites. The technique combines the measurement of local deformations during tests in a Scanning Electron Microscope and numerical simulations, in which the measurements are used as boundary conditions. Deformations are measured by placing a grid of markers on the surface of single fibre specimens. The displacements of these markers are measured during loading of the specimen. Numerical simulations show that the radial and tangential interface stresses increase towards the specimen surface, causing the initiation of debonding at the surface. This effect is supported by tests under an optical microscope. The interfacial normal strength is defined to be the maximum radial interface stress just before the initiation of debonding. Based on the presented results, it can be concluded that the presented technique is a promising tool for the measurement of the interfacial normal stress.

Effect of Heat Treatment on the Microstructure of Cu-Cr-Zr Alloy

2017 ◽  
Vol 727 ◽  
pp. 166-170 ◽  
Author(s):  
Li Jun Peng ◽  
Hao Feng Xie ◽  
Gao Lei Xu ◽  
Guo Jie Huang ◽  
Zhen Yang
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Volume Fraction ◽  
Homogenization Temperature ◽  
Eutectic Structure ◽  
Optical Microscope ◽  
Heat Treatments ◽  
Transmission Electron ◽  
The Matrix ◽  
Zr Alloy

Effect of Heat treatments on microstructure in a Cu-0.71Cr-0.12Zr alloy (in wt.%) have been investigated. The microstructures are analyzed by optical microscope, scanning electron microscope, transmission electron microscope and high-resolution transmission electron microscope after each step of heat treatments. The results show that the as-cast microstructure of Cu-Cr-Zr alloy is Cu matrix, Cr dendrite and eutectic structure which is composed of Cu and Cu5Zr phase with a fine lamellar structure. By increasing the homogenization temperature or prolonging the holding time, the eutectic structure is dissolved into the matrix gradually and the volume fraction of the Cr phases is obviously reduced. The precipitation of Cr phase prevents from Zr-rich phases dissolving in the matrix. And the proper homogenizing process is 900°C×12 h. When the alloy aged at 450°C for 24 h, the crystallography of Cr precipitates and the orientation relationship between Cr precipitates and Cu matrix is bcc structure and KS-OR, respectively. The disk-shaped precipitate is identified as Cu5Zr phase and their habit plane is parallel to {111}Cu plane.

Microstructure and Mechanical Properties of 0.15C-1.5Mn-0.3Si Steel Treated by Quenching and Partitioning Process

2014 ◽  
Vol 1063 ◽  
pp. 69-72
Author(s):  
Cai Nian Jing ◽  
Ji Chao Fan ◽  
Shu Bo Xu ◽  
Yi Sheng Zhang
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Retained Austenite ◽  
Lath Martensite ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Quenching And Partitioning ◽  
Microstructure And Mechanical Properties ◽  
Axial Tensile ◽  
Transmission Electron

In this paper, the microstructure and mechanical properties of 0.15C-1.5Mn-0.3Si steels after quenching and partitioning (Q&P) process was studied. The microstructure of experimental steels was characterized by optical microscope (OM), scan electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD), and mechanical properties were performed through uni-axial tensile tests. The microstructure evolution during Q&P process was also discussed together with mechanical properties. The investigated steels show excellent strength and ductility product of 10.76GPa% with retained austenite content of 11.08%. The microstructure mainly consists of lath martensite and retained austenite at room temperature, which promotes persistent work hardening during deformation.

The Effect of Grain Size on Superplastic Deformation of Ti-6Al-4V Alloy

2007 ◽  
Vol 551-552 ◽  
pp. 387-392 ◽  
Author(s):  
Wen Juan Zhao ◽  
Hua Ding ◽  
D. Song ◽  
F.R. Cao ◽  
Hong Liang Hou
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Superplastic Deformation ◽  
Initial Strain Rate ◽  
Deformation Mode ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Coarse Grained ◽  
Transmission Electron ◽  
Grain Growth Model

In this study, superplastic tensile tests were carried out for Ti-6Al-4V alloy using different initial grain sizes (2.6 μm, 6.5μm and 16.2 μm) at a temperature of 920°C with an initial strain rate of 1×10-3 s-1. To get an insight into the effect of grain size on the superplastic deformation mechanisms, the microstructures of deformed alloy were investigated by using an optical microscope and transmission electron microscope (TEM). The results indicate that there is dramatic difference in the superplastic deformation mode of fine and coarse grained Ti-6Al-4V alloy. Meanwhile, grain growth induced by superplastic deformation has also been clearly observed during deformation process, and the grain growth model including the static and strain induced part during superplastic deformation was utilized to analyze the data of Ti-6Al-4V alloy.

Organoclay-reinforced polyethersulfone-modified epoxy-based hybrid nanocomposites

2011 ◽  
Vol 23 (7) ◽  
pp. 526-534 ◽  
Author(s):  
Yang Wang ◽  
Boming Zhang ◽  
Jinrui Ye
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Optical Microscope ◽  
Mechanical Analysis ◽  
Hybrid Nanocomposites ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Modified Epoxy ◽  
Scanning Electron

Hybrid nanocomposites were successfully prepared by the incorporation of polyethersulfone (PES) and organoclay into epoxy resin. They had higher fracture toughness than the prepared PES/epoxy blend and organoclay/epoxy nanocomposites. The microstructures of the hybrid nanocomposites were studied. They were comprised of homogeneous PES/epoxy semi-interpenetrating network (semi-IPN) matrices and organoclay micro-agglomerates made up of tactoid-like regions composed of ordered exfoliated organoclay with various orientations. The former was confirmed with dynamic mechanical analysis, scanning electron microscopy and transmission electron microscopy, while the latter was successfully observed with X-ray diffraction measurements, optical microscope, scanning electron microscope and transmission electron microscope. The improvement of their fracture toughness was due to the synergistic toughening effect of the PES and the organoclay and related to their microstructures.

Gas metal arc welding of XPF800 steel for automotive industry: Microstructural evaluation and mechanical properties investigation

2021 ◽  
pp. 146442072110567
Author(s):  
Emre Korkmaz ◽  
Cemal Meran
Keyword(s):  
Mechanical Properties ◽  
Base Metal ◽  
Automotive Industry ◽  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Charpy Impact ◽  
Optical Microscope ◽  
Metal Arc Welding ◽  
Heat Affected Zone Softening

In this study, the effect of gas metal arc welding on the mechanical and microstructure properties of hot-rolled XPF800 steel newly produced by TATA Steel has been investigated. This steel finds its role in the automotive industry as chassis and seating applications. The microstructure transformation during gas metal arc welding has been analyzed using scanning electron microscope, optical microscope, and energy dispersive X-ray spectrometry. Tensile, Charpy impact, and microhardness tests have been implemented to determine the mechanical properties of welded samples. Acceptable welded joints have been obtained using heat input in the range of 0.28–0.46 kJ/mm. It has been found that the base metal hardness of the welded sample is 320 HV0.1. On account of the heat-affected zone softening, the intercritical heat-affected zone hardness values have diminished ∼20% compared to base metal.

scholarly journals Acceleration of Plasma Nitriding at 550 °C with Rare Earth on the Surface of 38CrMoAl Steel

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1122
Author(s):  
Dongjing Liu ◽  
Yuan You ◽  
Mufu Yan ◽  
Hongtao Chen ◽  
Rui Li ◽  
...  
Keyword(s):  
Rare Earth ◽  
Electron Microscope ◽  
Weight Gain ◽  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Surface Hardness ◽  
Optical Microscope ◽  
Steel Microstructure ◽  
Transmission Electron ◽  
Modified Layer

In order to explore the effect of the addition of rare earth (RE) to a steel microstructure and the consequent performance of a nitrided layer, plasma nitriding was carried out on 38CrMoAl steel in an atmosphere of NH3 at 550 °C for 4, 8, and 12 h. The modified layers were characterized using an optical microscope (OM), a microhardness tester, X-ray diffraction (XRD), a scanning electron microscope (SEM), a transmission electron microscope (TEM), and an electrochemical workstation. After 12 h of nitriding without RE, the modified layer thickness was 355.90 μm, the weight gain was 3.75 mg/cm2, and the surface hardness was 882.5 HV0.05. After 12 h of RE nitriding, the thickness of the modified layer was 390.8 μm, the weight gain was 3.87 mg/cm2, and the surface hardness was 1027 HV0.05. Compared with nitriding without RE, the ε-Fe2-3N diffraction peak was enhanced in the RE nitriding layer. After 12 h of RE nitriding, La, LaFeO3, and a trace amount of Fe2O3 appeared. The corrosion rate of the modified layer was at its lowest (15.089 × 10−2 mm/a), as was the current density (1.282 × 10−5 A/cm2); therefore, the corrosion resistance improved.

Microstructure of the Acid Welding Slag

2012 ◽  
Vol 249-250 ◽  
pp. 914-917
Author(s):  
Yuan Bin Zhang ◽  
Kai Zhang
Keyword(s):  
Electron Microscope ◽  
Amorphous Matrix ◽  
Low Carbon Steel ◽  
Optical Microscope ◽  
Crystal Phase ◽  
Low Carbon ◽  
Extrusion Press ◽  
Transmission Electron ◽  
Welding Slag ◽  
Welding Electrode

Several E4303 type welding electrodes with different coating compositions were designed and manufactured using TL-25 welding electrode extrusion press. Welding slags of these electrodes were collected after welding on the low carbon steel, then the microstructure and the phase constitutes of the slags were investigated by optical microscope,scan electron microscope (SEM), electron probe microanalyzer (EPMA), Transmission electron microscope (TEM) and X-ray diffraction (XRD). It was indicated that the slags were mainly composed of amorphous matrix and Fe2MnTi3O10 crystal phase. Fe, Mn and Ti were the main elements to form the crystal phase, while Si, Al and Ca were mostly distributed in the amorphous matrix. The formation of the crystal phase in the slag could be controlled by adjusting the amount and the proportion of Fe, Mn and Ti in the welding rod coating.

Microstructural Characterization and Tensile Behavior of TA1 Titanium Alloy Sheet Welded by Electron Beam Welding

2021 ◽  
Vol 1027 ◽  
pp. 149-154
Author(s):  
Sen Dong Gu ◽  
Ji Peng Zhao ◽  
Rui Jie Ouyang ◽  
Yong Hong Zhang
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
Fusion Zone ◽  
Heat Affected Zone ◽  
Electron Beam Welding ◽  
Base Material ◽  
Optical Microscope ◽  
Alloy Sheet ◽  
Tensile Behavior ◽  
Electron Backscattered Diffraction

In the present study, TA1 titanium alloy sheets with a thickness of 0.8mm were welded by electron beam welding. Microstructure of the welded region was investigated using optical microscope and electron backscattered diffraction. Then, the tensile test was conducted to analyse the tensile behavior of the welded sheets as well as the fractography of the fracture surfaces. It is shown that the mean grain size in the heat-affected zone is smaller than that in the fusion zone and base material. The strength of the base metal is lower than that of the fusion zone and heat-affected zone. The average values of the yield strength, tensile strength and elongation of the tensile specimens are 224MPa, 335MPa and 35%, respectively. In addition, the tensile specimens of the welded sheets suffer both ductile and brittle deformation during the tensile tests.

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