Characterization of Hot Deformation Behavior of a Novel Al-Cu-Li Alloy Using Processing Maps

doi:10.1007/s40195-015-0262-4

Abstract

Abstract:

The isothermally compression deformation behavior of an elevated Cu/Li weight ratio Al-Cu-Li alloy was investigated under various deformation conditions.The isothermal compression tests were carried out in a temperature range from 300 to 500°C and at a strain rate range from 0.001 to 10 s^-1.The results show that the peak stress level decreases with temperature increasing and strain rate decreasing, which is represented by the Zener-Hollomon parameter Z in the hyperbolic sine equation with the hot deformation activation energy of 218.5 kJ/mol.At low Z value, the dynamic recrystallized grain is well formed with clean high-angle boundaries.At high Z value, a high dislocation density with poorly developed cellularity and considerable fine dynamic precipitates are observed.Based on the experimental data and dynamic material model, the processing maps at strain of 0.3, 0.5 and 0.7 were developed to demonstrate the hot workability of the alloy.The results show that the main softening mechanism at high Z value is precipitate coarsening and dynamic recovery; the dynamic recrystallization of the alloy can be easily observed as ln Z ≤ 29.44, with peak efficiency of power dissipation of around 70%.At strains of 0.3, 0.5 and 0.7, the flow instability domains are found at higher strain rates, which mainly locate at the upper part of processing maps.In addition, when the strain rate is 0.001 or 0.02 s^-1, there is a particular instability domain at 300-350°C.

Key words: Al-Cu-Li alloy, Hot deformation behavior, Microstructure evolution, Processing maps

Xin-Xiang Yu, Yi-Ran Zhang, Deng-Feng Yin, Zhi-Ming Yu, Shu-Fei Li. Characterization of Hot Deformation Behavior of a Novel Al-Cu-Li Alloy Using Processing Maps[J]. Acta Metallurgica Sinica (English Letters), 2015, 28(7): 817-825.

Figures/Tables 13

Fig.1 Microstructure of the experimental alloy after homogenization treatment

Fig.2 Typical true stress-true strain curves of the experimental specimen under deformation strain rates: a10s-1; b1s-1; c 0.1s-1; d 0.01s-1; e 0.001s-1

Fig.3 Stresses soften amplitude (Δσ) of the alloy at different deformation temperatures and strain rates

Fig.4 Relationships between lnε? andlnσ a, lnε? andσ b, lnε? and ln(sinh(ασ)) c, ln(sinh(ασ)) and 1000/T d

Table 1 Values of ln Z under different deforming conditions

˙ε (s^-1)	Temperature (°C)
˙ε (s^-1)	300	350	400	450	500
10	48.17	44.49	41.36	38.65	36.30
1	45.88	42.19	39.05	36.35	34.00
0.1	43.57	39.88	36.75	34.05	31.70
0.01	41.26	37.58	34.45	31.75	29.39
0.001	38.96	35.28	32.14	29.44	27.09

Fig.5 Linear relationship between lnZ and ln[sinh(ασ)]

Table 2 Material constants and Q value of the experimental alloy

α(MPa-1)	A (s^-1)	n	Q (kJ/mol)
0.0118	3.446×10¹⁵	6.27	218.51

Fig.6 Power dissipation maps from the hot compression at various strains of 0.3 a, 0.5 b, 0.7 c

Fig.7 DMM processing maps of the experimental alloy at various strains of 0.3 a, 0.5 b, 0.7 c

Table 3 Ranges of temperature and strain rate for unsafe processing domains under different strains

Strain	Temperature (°C)	Strain rate (s^-1)
0.3	300-400	1-10
	420-490	3.162-10
	306-356	0.0016-0.02
0.5	300-500	0.631-10
0.5	303-360	0.0016-0.02
0.7	300-500	0.355-10
0.7	308-352	0.0022-0.0178

Fig.8 a SEM image of the alloy after homogenization treatment.b TEM image of the alloy after hot deformation at temperature of 300°C and strain rate of 10 s-1

Fig.9 Optical microscopy images of specimens deformed under different temperatures and at different strain rates: a 300°C, 10 s-1; b 350°C, 1 s-1; c 400°C, 0.1 s-1; d 450°C, 0.01 s-1; e 500°C, 0.001 s-1

Fig.10 TEM images of specimens deformed under different temperatures and at different strain rates: a 300°C, 10 s-1; b 350°C, 1 s-1; c 400°C, 0.1 s-1; d 450°C, 0.001 s-1

References 31

[1]	V. Araullo-Peters, B. Gault, F. DeGeuser, A. Deschamps, J. M.Cairney,Acta Mater.66, 199(2014)
[2]	N. Nayan, N. Murty, A.K. Jha, B. Pant, S.C. Sharma, K.M. George, G.V.S. Sastry, Mater. Sci. Eng. A 576, 21 (2013)
[3]	X.X. Yu, Z.M. Yu, D.F. Yin, H. Wang, A.Q. He, F. Cui,Rare Metal Mater.Eng.43, 495(2014).(in Chinese)
[4]	K.S. Kumar, F.H. Heubaum,Acta Mater.45, 2317(1996)
[5]	G. Itoh, Q. Cui, M. Kanno, Mater. Sci. Eng. A 211, 128 (1996)
[6]	Z.R. Pan, Z.Q. Zheng, Z.Q. Liao,Mater.Lett.64, 942(2010)
[7]	B. Gault, F.D. Geuser, L. Bourgeois, Ultramicroscopy 111, 207 (2011)
[8]	H.E. Hu, L. Zhen, L. Yang, W.Z. Shao, B.Y. Zhang, Mater. Sci. Eng. A 488, 64 (2008)
[9]	H.J. McQueen, X. Xia, Y. Cui, B. Li, Q. Meng, Mater. Sci. Eng. A 319, 420 (2001)
[10]	E. Cerri, E. Evangelista, A. Forcellese, H. McQueen, Mater. Sci. Eng.A 197, 181 (1995)
[11]	B. Chen, X.L. Tian, X. Li, C. Lu, J. Mater. Eng. Perform. 23, 1929 (2014)
[12]	B. Li, Q.L. Pan, Z.M. Yin, Mater. Sci. Eng. A 614, 199 (2014)
[13]	P.S. Robi, U.S. Dixit, J. Mater. Process. Technol.142, 289(2003)
[14]	M. Rajamuthamilselvan, S. Ramanathan, J. Alloys Compd. 509, 948(2011)
[15]	H.Z. Li, H.J. Wang, X.P. Liang, H.T. Liu, Y. Liu, X.M. Zhang, Mater. Sci. Eng. A 528, 1548 (2011)
[16]	X.X. Yu, D.F. Yin, Z.M. Yu, J. Wang, F. Cui,Rare Metal Mater. Eng.43, 1061(2014).(in Chinese)
[17]	H.Z. Li, Z. Li, M. Song, X.P. Liang, F.F. Guo, Mater. Des. 31, 2171 (2010)
[18]	S. Banerjee, P.S. Robi, A. Srinivasan, L.P. Kumar, Mater. Sci. Eng. A 527, 2498 (2010)
[19]	H. Dehghan, S.M. Abbasi, A. Momeni, A. KarimiTaheri, J. Alloys Compd. 564, 13(2013)
[20]	S.D. Liu, J.H. You, X.M. Zhang, Y.L. Deng, Y.B. Yuan, Mater. Sci. Eng. A 527, 1200 (2010)
[21]	Y.C. Lin, L.T. Li, Y.C. Xia, Y.Q. Jiang, J. Alloys Compd. 550, 438(2013)
[22]	M. Srinivasan, C. Loganathan, R. Narayanasamy, V. Senthilkumar, Q.B. Nguyen, M. Gupta,Mater.Des.47, 449(2013)
[23]	A. Łukaszek-Sołek, Acta Metall. Sin. (Engl.Lett.) 28, 22(2015)
[24]	Y.Q. Ning, Z.K. Yao, H.Z. Guo, M.W. Fu, J. Alloys Compd. 584, 494(2014)
[25]	A. Momeni, K. Dehghani, Mater. Sci. Eng.A 528, 1448 (2011)
[26]	J. Luo, M.Q. Li, B. Wu, Mater. Sci. Eng. A 530, 559 (2011)
[27]	B.M. Gable, A.W. Zhu, A.A. Csontos, E.A. Starke Jr, J. Light Met. 1, 1(2001)
[28]	J.B. Jia, K.F. Zhang, L.M. Liu, F.Y. Wu, J. Alloys Compd.600, 215(2014)
[29]	L. Li, X.M. Zhang, Mater. Sci. Eng. A 528, 1396 (2011)
[30]	X.D. Huang, H. Zhang, Y. Han, W.X. Wu, J.H. Chen, Mater. Sci. Eng. A 527, 485 (2010)
[31]	X.Y. Liu, Q.L. Pan, Y.B. He, W.B. Li, Z.M. Yin, Mater. Sci. Eng. A 500, 150 (2009)