Study on Microstructure and Properties of 5A06 Aluminum Alloy Welded Joint by Deep Cryogenic Treatment

2011 ◽  
Vol 314-316 ◽  
pp. 927-931 ◽  
Author(s):  
Shan Gao ◽  
Zhi Sheng Wu ◽  
Peng Fei Jin ◽  
Jun Jie Wang

In this paper, some deep cryogenic treatment experiments are first applied to 5A06 aluminum alloy welded joint at liquid nitrogen temperature (-155°C )for 4h, 8h, 10h respectively. 5A06 alloy welded joints before and after deep cryogenic treatment are observed by X-ray diffraction and scanning electrical microscopy. The experimental results have shown that the deep cryogenic treatment causesβphase of alloy to disperse and makes the grain smaller than that of joint before deep cryogenic treatment. Therefore, the mechanical properties of 5A06 alloy welded joints after deep cryogenic treatment are greatly improved.

2012 ◽  
Vol 724 ◽  
pp. 182-185 ◽  
Author(s):  
Shan Gao ◽  
Zhi Sheng Wu ◽  
Peng Fei Jin ◽  
Jun Jie Wang ◽  
Peng Shuai

5A06 aluminum alloy welding was obtained by using SAlMg-3 as welding wire with MIG (metal inert gas arc welding). The welded joint with deep cryogenic treatment at liquid nitrogen temperature (-155) for 4h, 8h, 10h were analyzed by metallographic and XRD examination. The results have shown that a lot of subgrain appears in the microstructure of the welded joint resulting in the refined grain after cryogenic treatment. The obvious increasing in content of β-phase (Mg2Al3) is distributed and dispersed evenly, contributed to dispersion strengthening of the welded joint. Meanwhile, orientation phenomena is obtained for some grain after deep cryogenic treatment. As a result, the microstructure of the joint can be modified by the deep cryogenic treatment.


2014 ◽  
Vol 59 (3) ◽  
pp. 911-918
Author(s):  
A. Ziewiec ◽  
E. Tasak ◽  
K. Ziewiec ◽  
K. Formowicz

Abstract The paper presents results of the mechanical testing and the microstructure analysis of dissimilar welded joint of the R350HT steel and the high-manganese (Hadfield) cast steel using Cr-Ni cast steel spacer. The simulation tests of the welded joint surface deformation were carried out. The macroscopic and microscopic investigation were made using light microscopy (LM) and scanning electron microscopy (SEM). Content of the magnetic phase was measured using magnetoscope. The quantitative metallographic investigation was used for assessment of ferrite and martensite contents and X-ray diffraction phase analysis was carried out. The results showed that during cooling of the spacer after welding, the transformation of metastable austenite into martensite proceeded. In addition to work hardening, the phase transformation of austenite into martensite occurs during the process of the superficial deformation of the spacer while simulated exploitation. This leads to a substantial increase of hardness, and at the same time, causes the increase of wear resistance of the welded joints of crossovers.


2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940032 ◽  
Author(s):  
Pengfei Zhu ◽  
Guoqing Gou ◽  
Zhaofu Li ◽  
Minhao Zhu ◽  
Zhongyin Zhu ◽  
...  

The welding residual stress has different effects on the mechanical properties of aluminum alloy welded joints, such as size stability, fatigue strength and stress corrosion cracking. Therefore, it is very important to evaluate the welding residual stress accurately. In this paper, the residual stress of A7N01 aluminum alloy welded joints was measured by X-ray diffraction. In contrast to the traditional method, the cos[Formula: see text] method was used in this paper, the results were compared with those obtained by the conventional [Formula: see text] method. In addition, the influence of oscillation unit on the test results of the cos[Formula: see text] method was studied.


2011 ◽  
Vol 317-319 ◽  
pp. 429-435 ◽  
Author(s):  
Dong Ying Ju ◽  
Xin Mao Fu ◽  
Shun Na ◽  
Bing Han ◽  
Xiao Hu Deng

Water jet cavitation peening is applied to improve the strength and mechanical properties of the friction-welded joints of titanium alloys. Scanning electron microscopy observations of the microstructure of the welded joints and welded area before/after water jet cavitation peening confirm slip dislocation at the microstructure near the surface of the specimens. The residual stress on the surface of the welded joint is measured by X-ray diffraction. The results indicate the effect of peening time on the strength of compressive residual stress.


Author(s):  
Idayan A ◽  
C. Elanchezhian ◽  
B. Vijaya Ramnath ◽  
Palanikumar K

In this research work, two types of cryogenic treatment such as deep cryogenic treatment (-196oC) and shallow cryogenic treatment (-80oC) have been adopted for wear resistance to increase in AISI 440C bearing steel. This paper has been focused to increase Wear Resistance (WR) through deep micro structural analyses, and also attention has been made to correlate the microstructure with the wear character of Deep Cryogenic treated (DCT) specimens, Conventional Heat Treated (CHT) specimens and Shallow Cryogenic Treated (SCT) specimens. Micro structural examinations have been carried out in the specimens through Scanning Electron Microscopy (SEM), Energy Dispersive Analysis of X-ray (EDAX) and X-Ray Diffraction (XRD). Wear characteristics of AISI 440C bearing steel has been studied. The outcome of the research disclosed that the DCT specimens have higher wear resistance than SCT and CHT specimens. The effective wear mechanisms recognized were the constitution of white layers and delamination of white layers. The microstructures of the materials have been varied through heat treatment process. The modification of Secondary Carbides (SCs) precipitation characteristics and its reduction of retained austenite in the microstructure have been correlated with wear character and these are the liable mechanism to raise the wear resistance of bearing steels through DCT.


2012 ◽  
Vol 217-219 ◽  
pp. 114-118 ◽  
Author(s):  
Xun Yin Zhang ◽  
Gui Rong Li ◽  
Ting Wang Zhang ◽  
Lei Cao ◽  
Hong Ming Wang ◽  
...  

Al2O3,Al3Ti and Al3Zr particles reinforced 7055 aluminium matrix composites were fabricated via melt reaction method. The volume fraction is controlled at about 4-5%. After extrusion and solution-aging heat treatment the sample was prepared for deep cryogenic treatment, The microstructure and evolution of mechanical properties of (Al3Ti+Al3Zr)p/7055 composites were analyzed using optical microscopy(OM),scanning electronic microscopy(SEM) and X-ray diffraction(XRD). Some θ(Al2Cu) phases with nanometer size precipitate in the inner grain. As some grains preferred orient the intensity of some main diffraction peaks increase. Compared with those of as-cast and squeezed states the micro hardness has increased by 16.8% and 10.0% separately.


2014 ◽  
Vol 881-883 ◽  
pp. 1846-1850
Author(s):  
Chun Guang Li ◽  
Zhong Chen Dai ◽  
Zhong Huang Yun ◽  
Dong Feng Li ◽  
Xing Hua Cao

Using the Renka Cline algorithm provided by OriginPro8.6 to fit the longitudinal residual stress through parts of the measurement value on the A7N01-T5 aluminum alloy butt welded joints compared with the whole measurement value. The result shows that the fitting value approximates the measurement value. The fitting value is reliable. So, Renka Cline algorithm is a reliable method to analyze the longitudinal residual stress on a plate region.


2018 ◽  
Vol 385 ◽  
pp. 385-390
Author(s):  
Aleksandr Malikov ◽  
Anatolii Orishich ◽  
Evgenij Karpov ◽  
Evgenij Sandalov

The paper deals with the analysis of the effect of the thermal mechanical processing on the mechanical characteristics (elasticity and tensile strength) of the welded joints of the aluminum alloy, the system Al-Mg-Li. The microstructures of the basic alloy and welded joint before and after the thermal processing are compared by electronic microscoping. The X-ray diffraction method is used to compare the phase composition. The concentration of the strengthening phase δʹ(Al3Li) reduces in the welded joint, which results in the low mechanical characteristics. The thermal processing, namely quenching, increases the concentration of the equilibrium S1 phase (Al2MgLi) in the welded joint as compared with an unquenched joint. The elasticity of the welded joint rises significantly at the almost constant strength, the value of the relative extension lies within the range of 2.4 – 19.2 % before and after quenching, respectively. Artificial ageing applied to the welded joint after the quenching gives the structurization of the S1 phase. The full thermal mechanical processing (quenching, elastic deformation, artificial ageing) of the welded joint of the aluminum alloy (the system AL-Mg-Li) results in the tensile strength increase up to 0.95 of the basic alloy strength.


Sign in / Sign up

Export Citation Format

Share Document