Studies on the Residual Stress Distribution for 2A02 Aluminum Forgings

Abstract:

High strength aluminum alloys which improve mechanical properties through heat treatment have been widely used in aviation manufacturing. However, residual stresses that are harmful to the materials are brought in during the heat treatment process. By means of the analysis of micro-indentation method and ANSYS finite element method, the residual stress distribution in 2A02aluminum forgings after water quenching were systematically investigated, mainly considering two factors of the symmetry of structure and the variation of surface constraint. The results of micro-indentation method show that the absolute value of the residual stress within the sample tends to decrease as the condition of constraint increase at the location of the same thickness; the absolute value of the surface residual stress also tends to decrease as the thickness of the sample increase with the same constraint conditions, the absolute value of the residual stress in the symmetrical sample is lower than that in the asymmetrical sample. The results of finite element simulation are as follows: for 2A02 aluminum alloy, the stress field distribution during the process of quenching is mainly influenced by the thickness of the samples. After the quenching process, the stress state at the components surface are controlled by compressive stress in the direction of both thickness and width, while the residual stress within the samples is dominated by tensile stress.

• Periodical: Applied Mechanics and Materials (Volume 529)
• Pages: 62-70
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.529.62
• Online since: June 2014
• Authors: Jiang Cao, Chun Fu Li*, Yan Wang, Shuang Fang
• Keywords: Aluminium Alloy, Finite Element Method (FEM), Micro-Indentation Method, Residual Stress

References

[1] Chen HN, Chen LS, Dong XZ. Drilling strains in measuring residual stress with hole-drilling strain-gage method. Transactions of the China welding institution. 1994, 15（4）：276-279.

[2] Hu YH, Wu YX, Chen L, Guo JK. Experimental measurement of surface residual stresses of quenched aluminum alloy thick plate by X-ray method. Materials China. 2011, 30 (2) : 51-54.

[3] Guo JK, Wu YX, Hu YH. Application of X-ray measurement of near surface residual stress in aluminum alloy thick plate. Light alloy fabrication technology. 2010, 38 (4) : 31-34.

[4] Tabor D. Hardness of metals. Oxford: Oxford University Press, (1951).

[5] Johnson K. L. Contact mechanics [M]. Cambridge: Cambridge University Press, (1985).

[6] Johnson, K.L. The correlation of indentation experiments. Journal of the Mechanics and Physics of Solids, 1970, 18 (2) : 115~126.

[7] Carlsson S, Larsson P. L. On the determination of residual stress and strain fields by sharp indentation testing. Part 1: theoretical and numerical analysis. Acta Mater 2001; 49: 2179-91.

DOI: 10.1016/s1359-6454(01)00122-7

[8] Carlsson S, Larsson P. L. On the determination of residual stress and strain fields by sharp indentation testing. Part 2: experimental investigation. Acta Mater 2001; 49: 2193-203.

DOI: 10.1016/s1359-6454(01)00123-9

[9] Sun AG, Chen B. The technology and application of residual stress analysis by neutron diffraction . nucleus technology. 2007, 30 (4) : 286-289.

[10] Jiang G, Tan MH, Wang WM, He W. Present research status of measuring residual stress. Machine tool & hydraulics. 2007, 35 (6) : 213-216.

[11] Li YC. Reasons of causing alumina diaphragm defects in 2A02 aluminum alloy ingot and concerned preventive. Light alloy fabrication technology. 2005, 33 (7): 20-22.

[12] Liu B, Peng CQ, Wang RC, Wang XF, Li TT. Recent development and prospects for giant plane aluminum alloys. The Chinese journal of Nonferrous Metals. 2010 , (09) : 1705-1715.

[13] Yang YC. Secondary aluminum-a green industry suited to the sustainable development. Engineering science. 2007, 5 (1) : 24-32.

[14] Zhou Q, Dai H. A method for estimating residual stress by nicroindent ation hardness testing. PTCA. 2007, 43 (6) : 290-292, 304.

[15] Per-Lennart Larsson, Investigation of sharp contact at rigid-plastic conditions, International journal of mechanical science 43 (2001) 895-920.

DOI: 10.1016/s0020-7403(00)00056-4

[16] Per-Lennart Larsson, On the mechanical behavior at sharp indentation of materials with compressive residual stresses, Materials and design 32 (2011) 1427-1434.

DOI: 10.1016/j.matdes.2010.09.004

[17] Per-Lennart Larsson, Pierre Blanchard, On the correlation between residual stresses and globle indentation quantities: Numerical results for general biaxial stress fields, Materials and design 37 (2012) 435-442.

DOI: 10.1016/j.matdes.2012.01.032