铸造铝合金微观组织对应变硬化指数预测的影响
收稿日期: 2009-07-13
修回日期: 2009-10-21
网络出版日期: 2010-02-10
基金资助
国家自然科学基金项目50771073和国家重点基础研究发展计划项目2007CB714705资助
EFFECT OF MICROSTRUCTURES ON STRAIN HARDENING EXPONENT PREDICTION OF CAST ALUMINUM ALLOY
Received date: 2009-07-13
Revised date: 2009-10-21
Online published: 2010-02-10
Supported by
Supported by National Natural Science Foundation of China (No.50771073) and National Basic Research Program of China (No.2007CB714705)
研究了铸造铝合金的微观组织参数包括二次枝晶臂间距(SDAS)、Si颗粒的形貌率和体积分数, 与拉伸过程中内应力的关系, 根据Hollomon和内应力公式建立了应变硬化指数n的定量预测关系式. 结果表明: n值反映了材料在较大塑性变形下(在发生塑性松弛以后)的硬化能力. 定义了微结构硬化能力参数, 并用常见的几种铸造铝合金材料进行了验证. 所推导的理论关系式及线性拟合关系式能较好地预测n值, 对同一牌号的铸造铝合金材料, n值对颗粒相形貌率和
SDAS的依赖性强, 而对颗粒相体积分数的依赖性不明显, 颗粒相形貌率和SDAS值越大, n值越小. 对A319和A356/357铝合金, 最佳修正系数分别是0.17和0.11,预测平均误差在10%左右.
莫德锋 , 何国球 , 胡正飞 , 刘晓山 , 张卫华 . 铸造铝合金微观组织对应变硬化指数预测的影响[J]. 金属学报, 2010 , 46(2) : 184 -188 . DOI: 10.3724/SP.J.1037.2009.00474
Strain hardening exponent (n) of a material is an important parameter reflecting its hardening property whose determination is of great importance. It has a widely application in material scientific research and engineering fields such as fatigue life prediction, stress–concentration–factor calculation, etc.. The value of strain hardening exponent varies with their microstructures in cast aluminum alloys, but a few theoretical and experimental investigations have been reported to understand the effects of the microstructural parameters on the strain hardening exponent in these alloys till now. In the present study, the influence of secondary dendrite arm spacing (SADS), aspect ratio and volume fraction of particles on internal stress in aluminum alloys were discussed, and a quantitative prediction of strain hardening exponnt was established on the basis of Hollomon and internal stress equations. It shows tat the strain hardening exponent represents their hardening ability in relatively large plastic deformation (larger than the upper limit for the no plastic relaxation regime). A new microstructural hardening parameter relatively to strain hardening exponent was defined. Besides, a group of A319 cast aluminum alloys with microstructural heterogeneities were tested. The calculated strain hardening exponents are in agreement with the experimental ones in A319 alloy as well as in some commonly used cast aluminum alloys. For the same grade of alloys, the microstructural hardening parameter and strain hardening exponent are quite sensitive to SDAS and particle aspect ratio while the influence of volume fraction of particles is reltivey little. As the values of SDAS and aspect ratio of particles increse, the vlue of te strain harening exponent decreases. A lier reltionship between microstructural hardeig parameter and strain hardening exponent was proposd. For A319 and A356/57 alloys, the optimum correctin coefficients are 0.17 and 0.11, respectively, and the mean prediction error of n is only bout 10%.
[1] Miller W S, Zhuang L, Bottema J, Wittebrood A J, De Smet P, Haszler A, Vieregge A. Mater Sci Eng, 2000; A280: 37
[2] Wang Q G. Metall Mater Trans, 2004; A35: 2707
[3] C´aceres C H, Selling B I. Mater Sci Eng, 1996; A220: 109
[4] Fatahalla N, Hafiz M, Abdulkhalek M. J Mater Sci, 1999; 34: 3555
[5] Wang Q G. Metall Mater Trans, 2003; 34A: 2887
[6] Han Y, Chen S J. Phys Test Chem Anal (Phys Test), 2003; 39: 555
(韩茵, 陈诗键. 理化检验(物理分册), 2003; 39: 555)
[7] Hu Z Z, Cao S Z. J Xi’an Jiaotong Univ, 1993; 27: 71
(胡志忠, 曹淑珍. 西安交通大学学报, 1993; 27: 71)
[8] Morrison W B. Trans ASM, 1996; 59: 824
[9] Antoine P, Vandeputte S, Vogt J B. Mater Sci Eng, 2006; A433: 55
[10] Caceres C H, Griffiths J R, Reiner P. Acta Mater, 1996; 44: 15
[11] Sandor B I ed., transl. by Yu J L. Fundamentals of Cyclic Stress and Strain. Beijing: Science Press, 1985: 59
(Sandor B I著, 俞炯亮译. 循环应力与循环应变的基本原理. 北京:科学出版社, 1985: 59)
[12] Suresh S ed., transl. by Wang Z G. Fatigue of Materials. 2nd Ed., Beijing: National Defence Industry Press, 1999: 218
(Suresh S著; 王中光译. 材料的疲劳(第2版). 北京: 国防工业出版社, 1999: 218)
[13] Ebrahimi R, Pardisa N. Mater Sci Eng, 2009; A518: 56
[14] Mo D F, He G Q, Hu Z F, Zhu Z Y, Chen C S, Zhang W H. Int J Fatigue, 2008; 30: 1843
[15] Wang Q G, Apelian D, Lados D A. J Light Met, 2001; 1: 85
[16] Ovono Ovono D, Guillot I, Massinon D. J Alloys Compd, 2008; 452: 425
[17] Sowerby R, Uko D K, Tomita Y. Mater Sci Eng, 1979; 41: 43
[18] Brown L M, Clarke D R. Acta Metall, 1975; 23: 821
[19] Han C S, Wagonera R H, Barlat F. Int J Plast, 2004; 20: 477
[20] Brown L M. Acta Metall, 1973; 21: 879
[21] Hansen N. Acta Metall, 1977; 25: 863
[22] Ashby M F. Philos Mag, 1970; 21: 399
[23] Hansen N, Huang X. Acta Mater, 1998; 46: 1827
[24] Caceres C H, Griffiths J R. Acta Mater, 1996; 44: 25
[25] Kleemola H J, Nieminen M A. Metall Mater Trans, 1974; 5B: 1863
[26] Hutchinson J W, Obrecht H. Fracture, 1977; 1: 101
[27] Wang Q G, Apelian D, Lados D A. J Light Met, 2001; 1: 73
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