scholarly journals Numerical and Experimental Research on Cold Compression Deformation Method for Reducing Quenching Residual Stress of 7A85 Aluminum Alloy Thick Block Forging

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Cui Jin-dong ◽  
Yi You-ping ◽  
Luo Guo-yun

In aeronautical machining industry, the most difficult problem to deal with is the distortion of aviation integral component, one main cause of which is the existence of quenching residual stress of forgings, especially for large-sized ones. Therefore, it is important to study the methods that can reduce the quenching residual stress. In this work, the distribution of quenching residual stress of 7A85 aluminum alloy thick block forging, as well as the effect of cold compression deformation method on reducing quenching residual stress, has been investigated by simulation. The results show that, in length direction of 7A85 aluminum alloy thick block with a large size of 260 (H) × 1150 (W) × 5300 (L) mm, quenching residual stress can be significantly reduced by about 2.5% cold compression deformation along the direction of highness, with residual stress in length direction ranging from −65 MPa to 60 MPa, compared with its counterpart after quenching from −170 MPa to 140 MPa. Then a cold compression experiment was carried out, in which the forging residual stress on the surface was measured by X-ray diffraction device. The experimental results indicate that the optimal compression deformation value is 1%-2%, reducing 70% residual stress for 7A85 aluminum alloy specimens in size of 100 (L) × 60 (W) × 40 (H) mm.

2012 ◽  
Vol 499 ◽  
pp. 217-222 ◽  
Author(s):  
C. Li ◽  
Yi Wan ◽  
R.R. Zhang ◽  
Zhan Qiang Liu

The residual stress in the milling of 7050-T7451 aluminum alloy was measured using X-ray diffraction method in which Psi-oscillation, Phi-oscillation and peak fit were adopted. Cutting speed and feed are main variables which were considered in this study. The results show that compressive residual stresses are generated in surface for the down milling generally, which is mainly due to burnishing effect between the tools flank face and the machined surface. In feed and its orthogonal direction, the effect of cutting speed and feed speed on residual stress is similar. Therefore, required residual stress can be achieved by controlling the cutting condition such as cutting speed, feed speed etc.


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 462-463 ◽  
pp. 343-348 ◽  
Author(s):  
Omar Suliman Zaroog ◽  
Aidy Ali ◽  
Sahari B. Barkawi ◽  
Rizal Zahari

The residual stress relaxation can be divided into two stages: The first cycle relaxation and the following cycles. In both stages, residual stress relaxed considerably from the initial state. The aim of this study is to investigate the residual stress relaxation and microhardness reduction after first and second cyclic load. A 2024 T351 aluminum alloy specimens were shot peened into three shot peening intensities. The fatigue test for first and second cyclic loads of two loads 15.5 kN and 30 kN was performed. The initial residual stress and residual stress after the first and second cycle stress was measured for the three shot peening intensities using X-ray diffraction. Microhardness test was performed for each specimen. The results showed that the residual stress relaxation for first cycle was reached more than 40% of the initial residual stress and it depends on the load amplitude, and microhardness decreased for the first cycle reached 22% and also it depended on load amplitude.


2013 ◽  
Vol 834-836 ◽  
pp. 416-419
Author(s):  
Tong He ◽  
Ning Zhang ◽  
Wei Sun

AA6016 aluminum alloy with a strong β fiber rolling texture was cold rolled to different reductions by means of a special deformation method (side rolling in Chinese). The texture development during side rolling was investigated by X-ray diffraction. The typical B, S and C orientation on the β fiber are transformed into the B'{111}, S'{22 17 9} and C'{011} orientations, respectively. The results show that these orientations are unstable and gradually rotate to the B orientation in the new sample reference frame.


2010 ◽  
Vol 43 ◽  
pp. 687-690
Author(s):  
Ai Xin Feng ◽  
Chuan Chao Xu ◽  
Yu Peng Cao ◽  
Huai Yang Sun ◽  
Gui Fen Ni ◽  
...  

X-ray diffraction analysis methods analyze the residual stress the same location for 50 times of 7050 aluminum alloy. And taking residual stress error for statistical analysis, through hypothesis testing and analysis of the residual stress error Square diagram, obtain X-ray diffraction the residual stress error of the 7050 aluminum alloy approximately obey normal distribution.


2011 ◽  
Vol 284-286 ◽  
pp. 284-292 ◽  
Author(s):  
Shao Chun Sun ◽  
Zhi Yuan Chen ◽  
Qiang Wu ◽  
De Xin Ma ◽  
Yu Tao Zhao

In locally long fiber reinforced aluminum parts two types residual stresses exist. They are the microscopic residual stress between fiber and matrix and the macroscopic residual stress between reinforced and unreinforced zones. The residual stresses between fiber and matrix in γ-Al2O3 long fiber reinforced aluminum alloy Al-6-1-1 were measured with X-ray Diffraction process as well as simulated with FEM method. The results indicated that the residual stresses in both fiber and matrix were distributed very unequally. The maximum tensile residual stress occurred at the boundary in the matrix and the maximum compressive residual stresses occurred near the boundary in the fiber. The macroscopic residual stresses between the reinforced and unreinforced zones were also measured with borehole method as well as simulated with FEM. It was found that the macroscopic residual stresses at most locations in both the reinforced and unreinforced zones were not harmfully high. However in both reinforced and unreinforced zones there were small sub-zones of very large tensile residual stresses.


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.


2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940038
Author(s):  
Zhongyin Zhu ◽  
Guoqing Gou ◽  
Zhiyi Zhang ◽  
Chuanping Ma ◽  
Wei Gao

The residual stress beneath the surface is crucial to the safety of the structures. Neutron Diffraction and Hole-drilling are the two methods being used to measure the inner residual stress. Longitudinal Critically Refracted (LCR) wave transmission that is propagated parallel to surface also can be used for measuring residual stress, but measurements are within an effective depth and need to be further studied. In this paper, the parameters of K are separately tested in WZ, HAZ and BM zone. The welding process of 6082-T6 aluminum alloy welded joints is simulated in SYSWELD, the finite element model has been verified by the X-ray diffraction method. The residual stress value calculated by SYSWELD and the values obtained from the ultrasonic measurement show a good agreement. It is demonstrated that the residual stress of 6082-T6 aluminum alloy welded plate can be evaluated by using the ultrasonic method.


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