Effects of Tool Rotation Rates on Superplastic Deformation Behavior of Friction Stir Processed Mg-Zn-Y-Zr Alloy

doi:10.11900/0412.1961.2018.00174

Acta Metall Sin

2018, Vol. 54

Issue (12): 1745-1755 DOI: 10.11900/0412.1961.2018.00174

Orginal Article

Current Issue | Archive | Adv Search

Effects of Tool Rotation Rates on Superplastic Deformation Behavior of Friction Stir Processed Mg-Zn-Y-Zr Alloy

Guangming XIE¹(

), Zongyi MA², Peng XUE², Zongan LUO¹, Guodong WANG¹

1 State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China
2 Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China

Cite this article:

Guangming XIE, Zongyi MA, Peng XUE, Zongan LUO, Guodong WANG. Effects of Tool Rotation Rates on Superplastic Deformation Behavior of Friction Stir Processed Mg-Zn-Y-Zr Alloy. Acta Metall Sin, 2018, 54(12): 1745-1755.

Download:

HTML

PDF(10684KB)
Export: BibTeX | EndNote (RIS)

Abstract

Compared to conventional Mg-Al and Mg-Zn system magnesium alloys, the Mg-Zn-Y-Zr heat-resistant alloy exhibits high thermal stability due to the addition of Y earth element, which is an ideal candidate for producing high strain rate superplasticity (HSRS, strain rate≥1×10^-2 s^-1). Recently, the HSRS of Mg-Zn-Y-Zr alloy was achieved by friction stir processing (FSP), because the FSP resulted in the generation of fine and equiaxed recrystallized grains and fine and homogeneous second phase particles. However, the study on superplastic deformation mechanism of FSP Mg-Zn-Y-Zr alloy at various parameters is limited relatively. Therefore, at the present work, six millimeters thick as-extruded Mg-Zn-Y-Zr plates were subjected to FSP at relatively wide heat input range of rotation rates of 800 r/min to 1600 r/min with a constant traverse speed of 100 mm/min, obtaining FSP samples consisting of homogeneous, fine and equiaxed dynamically recrystallized grains and fine and uniform Mg-Zn-Y ternary phase (W-phase) particles. With increasing rotation rate, within the FSP samples the W-phase particles were broken up and dispersed significantly and the recrystallized grains were refined slightly, while the fraction ratio of the high angle grain boundaries (grain boundaries misorientation angle≥15°) was increased obviously. Increasing rotation rate resulted in an increase in both optimum strain rate and superplastic elongation. For the FSP sample obtained at 1600 r/min, a maximum elongation of 1200% was achieved at a high-strain rate of 1×10^-2 s^-1 and 450 ℃. Grain boundary sliding was identified to be the primary deformation mechanism in the FSP samples at various rotation rates by superplastic data analyses and surfacial morphology observations. Furthermore, the increase in rotation rate accelerated superplastic deformation kinetics remarkably. For the FSP sample at 1600 r/min, superplastic deformation kinetics is in good agreement with the prediction by the superplastic constitutive equation for fine-grained magnesium alloys governed by grain boundary sliding mechanism.

Key words: friction stir processing magnesium alloy superplasticity grain boundary

Received: 02 May 2018

ZTFLH:

TG456.9

Fund: Supported by National Natural Science Foundation of China (Nos.51774085 and 51671190) and Fundamental Research for the Central Universities (No.N170704013)

	Service

	E-mail this article
	Add to citation manager
	E-mail Alert
	RSS
	（）
	Articles by authors
	Guangming XIE
	Zongyi MA
	Peng XUE
	Zongan LUO
	Guodong WANG

URL:

https://www.ams.org.cn/EN/10.11900/0412.1961.2018.00174 OR https://www.ams.org.cn/EN/Y2018/V54/I12/1745

Fig.1 OM images of parent Mg-Zn-Y-Zr alloy (a) and FSP samples at rotation rates of 800 r/min (b), 1200 r/min (c) and 1600 r/min (d) (FSP—friction stir processing, the black particles are the second phases)

Fig.2 SEM images of parent Mg-Zn-Y-Zr alloy (a) and FSP samples at rotation rates of 800 r/min (b), 1200 r/min (c) and 1600 r/min (d) (The white particles are the second phases)

Fig.3 EPMA element maps of Mg (a, d), Zn (b, e) and Y (c, f) in parent Mg-Zn-Y-Zr alloy (a~c) and FSP sample at rotation rate of 1600 r/min (d~f)

Fig.4 XRD spectra of parent Mg-Zn-Y-Zr alloy (a) and FSP sample at rotation rate of 1600 r/min (b)

Fig.5 EBSD orientation maps of parent Mg-Zn-Y-Zr alloy (a) and FSP samples at rotation rates of 800 r/min (b), 1200 r/min (c) and 1600 r/min (d) (The black and white lines represent the high angle grain boundaries (HAGBs, grain boundaries misorientation angle≥15°) and low angle grain boundaries (LAGBs, 2°≤grain boundaries misorientation angle<15°), respectively)

Fig.6 Grain boundary misorientation angle distributions of parent Mg-Zn-Y-Zr alloy (a) and FSP samples at rotation rates of 800 r/min (b), 1200 r/min (c) and 1600 r/min (d) (The black curves show the random misorientation angle distribution for hcp structural metal)

Fig.7 Relationships of elongation with initial strain rate at 400 ℃ (a) and 450 ℃ (b) for FSP samples at rotation rates of 800, 1200 and 1600 r/min with traverse speed of 100 mm/min

Fig.8 Relationships of flow stress with initial strain rate at 400 ℃ (a) and 450 ℃ (b) for FSP samples at rotation rates of 800, 1200 and 1600 r/min (m—strain rate sensitive exponent)

Fig.9 Macrographs of untested and failed tensile FSP specimens at rotation rates of 800 r/min (a), 1200 r/min (b) and 1600 r/min (c) at test temperatures of 400 ℃ (a) and 450 ℃ (b, c)

Fig.10 SEM images of fracture surface of FSP samples at 800 r/min deformed under 400 ℃ and 1×10^-3 s^-1 (a), at 1200 r/min deformed under 450 ℃ and 3×10^-3 s^-1 (b) and at 1600 r/min deformed under 450 ℃ and 1×10^-2 s^-1 (c)

Fig.11 Relationships between

ε ˙ kT d 3 D 0 - 1 G - 1 b - 4

and normalized effective stress

σ G - 1

for FSP samples at rotation rates of 800, 1200 and 1600 r/min (

ε ˙

—strain rate, σ—flow stress, D₀—pre-exponential constant for diffusivity, G—shear modulus, b—Burgers vector, k—Boltzmann's constant, T—absolute temperature, R—gas constant, d—grain size)

[1]	Polmear I J.Light Alloys: Metallurgy of the Light Metals[M]. 3rd Ed., London: Butterworth-Heinemann, 1995: 1
[2]	Avedesian M M, Baker H.Magnesium and Magnesium Alloys[M]. 2nd Ed., Ohio: ASM International, 1999: 1
[3]	Watanabe H, Mukai T, Kohzu M, et al.Effect of temperature and grain size on the dominant diffusion process for superplastic flow in an AZ61 magnesium alloy[J]. Acta Mater., 1999, 47: 3753
[4]	Watanabe H, Mukai T, Ishikawa K, et al.Low temperature superplasticity of a fine-grained ZK60 magnesium alloy processed by equal-channel-angular extrusion[J]. Scr. Mater., 2002, 46: 851
[5]	Al-Samman T.Modification of texture and microstructure of magnesium alloy extrusions by particle-stimulated recrystallization[J]. Mater. Sci. Eng., 2013, A560: 561
[6]	Hantzsche K, Bohlen J, Wendt J, et al.Effect of rare earth additions on microstructure and texture development of magnesium alloy sheets[J]. Scr. Mater., 2010, 63: 725
[7]	Hou X L, Zhai Y X, Zhang P, et al.Rare earth texture analysis of rectangular extruded Mg alloys and a comparison of different alloying adding ways[J]. Rare Met., 2016, 35: 850
[8]	Xie G M, Ma Z Y, Geng L, et al.Microstructural evolution and mechanical properties of friction stir welded Mg-Zn-Y-Zr alloy[J]. Mater. Sci. Eng., 2007, A471: 63
[9]	Zheng M Y, Xu S W, Wu K, et al.Superplasticity of Mg-Zn-Y alloy containing quasicrystal phase processed by equal channel angular pressing[J]. Mater. Lett., 2007, 61: 4406
[10]	Bae D H, Kim Y, Kim I J.Thermally stable quasicrystalline phase in a superplastic Mg-Zn-Y-Zr alloy[J]. Mater. Lett., 2006, 60: 2190
[11]	Tang W N, Chen R S, Han E H.Superplastic behaviors of Mg-Zn-Y-Zr alloy processed by extrusion and equal channel angular extrusion[J]. J. Alloys Compd., 2009, 477: 636
[12]	Xu S W, Zheng M Y, Kamado S, et al.The microstructural evolution and superplastic behavior at low temperatures of Mg-5.00Zn-0.92Y-0.16Zr (wt.%) alloys after hot extrusion and ECAP process[J]. Mater. Sci. Eng., 2012, A549: 60
[13]	Mishra R S, Ma Z Y.Friction stir welding and processing[J]. Mater. Sci. Eng., 2005, R50: 1
[14]	Padhy G K, Wu C S, Gao S.Friction stir based welding and processing technologies-processes, parameters, microstructures and applications: A review[J]. J. Mater. Sci. Technol., 2018, 34: 1
[15]	Chen Y C, Liu H J, Feng J C.Friction stir welding characteristics of different heat-treated-state 2219 aluminum alloy plates[J]. Mater. Sci. Eng., 2006, A420: 21
[16]	Yang C, Wang J J, Ma Z Y, et al.Friction stir welding and low-temperature superplasticity of 7B04 Al sheet[J]. Acta Metall. Sin., 2015, 51: 1449(杨超, 王继杰, 马宗义等. 7B04铝合金薄板的搅拌摩擦焊接及接头低温超塑性研究[J]. 金属学报, 2015, 51: 1449)
[17]	Ma Z Y, Liu F C, Mishra R S.Superplastic deformation mechanism of an ultrafine-grained aluminum alloy produced by friction stir processing[J]. Acta Mater., 2010, 58: 4693
[18]	Wang K, Liu F C, Xue P, et al.Superplastic constitutive equation including percentage of high-angle grain boundaries as a microstructural parameter[J]. Metall. Mater. Trans., 2016, 47A: 546
[19]	Ma Z Y, Mishra R S.Friction Stir Superplasticity for Unitized Structures[M]. Waltham: Elsevier, 2014: 1
[20]	Yang Q, Feng A H, Xiao B L, et al.Influence of texture on superplastic behavior of friction stir processed ZK60 magnesium alloy[J]. Mater. Sci. Eng., 2012, A556: 671
[21]	Chai F, Zhang D T, Li Y Y, et al.High strain rate superplasticity of a fine-grained AZ91 magnesium alloy prepared by submerged friction stir processing[J]. Mater. Sci. Eng., 2013, A568: 40
[22]	Zhang D T, Wang S X, Qiu C, et al.Superplastic tensile behavior of a fine-grained AZ91 magnesium alloy prepared by friction stir processing[J]. Mater. Sci. Eng., 2012, A556: 100
[23]	Xie G M, Luo Z A, Ma Z Y, et al.Superplastic behavior of friction stir processed Zk60 magnesium alloy[J]. Mater. Trans., 2011, 52: 2278
[24]	Xie G M, Ma Z Y, Geng L, et al.Microstructural evolution and enhanced superplasticity in friction stir processed Mg-Zn-Y-Zr alloy[J]. J. Mater. Res., 2008, 23: 1207
[25]	Yang Q, Xiao B L, Ma Z Y, et al.Achieving high strain rate superplasticity in Mg-Zn-Y-Zr alloy produced by friction stir processing[J]. Scr. Mater., 2011, 65: 335
[26]	Yang J, Wang D, Xiao B L, et al.Effects of rotation rates on microstructure, mechanical properties, and fracture behavior of friction stir-welded (FSW) AZ31 magnesium alloy[J]. Metall. Mater. Trans., 2013, 44A: 517
[27]	Xie G M, Ma Z Y, Geng L.Effects of friction stir welding parameters on microstructures and mechanical properties of ZK60 magnesium alloy joints[J]. Acta Metall. Sin., 2008, 44: 665(谢广明, 马宗义, 耿林. 搅拌摩擦焊接参数对ZK60镁合金接头微观组织和力学性能的影响[J]. 金属学报, 2008, 44: 665)
[28]	Feng A H, Ma Z Y.Microstructural evolution of cast Mg-Al-Zn during friction stir processing and subsequent aging[J]. Acta Mater., 2009, 57: 4248
[29]	Kim W J, Park J D, Kim W Y.Effect of differential speed rolling on microstructure and mechanical properties of an AZ91 magnesium alloy[J]. J. Alloys Compd., 2008, 460: 289
[30]	Langdon T G.A unified approach to grain boundary sliding in creep and superplasticity[J]. Acta Metall. Mater., 1994, 42: 2437
[31]	Ma Z Y, Mishra R S, Mahoney M W.Superplastic deformation behaviour of friction stir processed 7075Al alloy[J]. Acta Mater., 2002, 50: 4419
[32]	Ball E A, Pangnell P B.Tensile-compressive yield asymmetries in high strength wrought magnesium alloys[J]. Scr. Metall. Mater., 1994, 31: 111
[33]	Abbasi M, Nelson T W, Sorensen C D.Transformation and deformation texture study in friction stir processed API X80 pipeline steel[J]. Metall. Mater. Trans., 2012, 43A: 4940
[34]	Mironov S, Sato Y S, Kokawa H, et al.Structural response of superaustenitic stainless steel to friction stir welding[J]. Acta Mater., 2011, 59: 5472
[35]	Sastry D H, Prasad Y V R K, Vasu K I. On the stacking fault energies of some close-packed hexagonal metals[J]. Scr. Metall., 1969, 3: 927
[36]	Woo W, Choo H, Brown D W, et al.Texture variation and its influence on the tensile behavior of a friction-stir processed magnesium alloy[J]. Scr. Mater., 2006, 54: 1859
[37]	Agnew S R, Yoo M H, Tome C N.Application of texture simulation to understanding mechanical behavior of Mg and solid solution alloys containing Li or Y[J]. Acta Mater., 2001, 49: 4277
[38]	Watanabe H, Hosokawa H, Mukai T, et al.The processing and properties of superplastic magnesium alloys and their composites[J]. Mater. Jpn., 2000, 39: 347

[1]	ZHANG Haifeng, YAN Haile, FANG Feng, JIA Nan. Molecular Dynamic Simulations of Deformation Mechanisms for FeMnCoCrNi High-Entropy Alloy Bicrystal Micropillars[J]. 金属学报, 2023, 59(8): 1051-1064.
[2]	XU Yongsheng, ZHANG Weigang, XU Lingchao, DAN Wenjiao. Simulation of Deformation Coordination and Hardening Behavior in Ferrite-Ferrite Grain Boundary[J]. 金属学报, 2023, 59(8): 1042-1050.
[3]	CHANG Songtao, ZHANG Fang, SHA Yuhui, ZUO Liang. Recrystallization Texture Competition Mediated by Segregation Element in Body-Centered Cubic Metals[J]. 金属学报, 2023, 59(8): 1065-1074.
[4]	WANG Zongpu, WANG Weiguo, Rohrer Gregory S, CHEN Song, HONG Lihua, LIN Yan, FENG Xiaozheng, REN Shuai, ZHOU Bangxin. {111}/{111} Near Singular Boundaries in an Al-Zn-Mg-Cu Alloy Recrystallized After Rolling at Different Temperatures[J]. 金属学报, 2023, 59(7): 947-960.
[5]	LI Fulin, FU Rui, BAI Yunrui, MENG Lingchao, TAN Haibing, ZHONG Yan, TIAN Wei, DU Jinhui, TIAN Zhiling. Effects of Initial Grain Size and Strengthening Phase on Thermal Deformation and Recrystallization Behavior of GH4096 Superalloy[J]. 金属学报, 2023, 59(7): 855-870.
[6]	SHAO Xiaohong, PENG Zhenzhen, JIN Qianqian, MA Xiuliang. Unravelling the { $10 1 ¯ 2$ } Twin Intersection Between LPSO Structure/SFs in Magnesium Alloy[J]. 金属学报, 2023, 59(4): 556-566.
[7]	TANG Weineng, MO Ning, HOU Juan. Research Progress of Additively Manufactured Magnesium Alloys: A Review[J]. 金属学报, 2023, 59(2): 205-225.
[8]	ZHU Yunpeng, QIN Jiayu, WANG Jinhui, MA Hongbin, JIN Peipeng, LI Peijie. Microstructure and Properties of AZ61 Ultra-Fine Grained Magnesium Alloy Prepared by Mechanical Milling and Powder Metallurgy Processing[J]. 金属学报, 2023, 59(2): 257-266.
[9]	LI Xin, JIANG He, YAO Zhihao, DONG Jianxin. Theoretical Calculation and Analysis of the Effect of Oxygen Atom on the Grain Boundary of Superalloy Matrices Ni, Co and NiCr[J]. 金属学报, 2023, 59(2): 309-318.
[10]	YANG Du, BAI Qin, HU Yue, ZHANG Yong, LI Zhijun, JIANG Li, XIA Shuang, ZHOU Bangxin. Fractal Analysis of the Effect of Grain Boundary Character on Te-Induced Brittle Cracking in GH3535 Alloy[J]. 金属学报, 2023, 59(2): 248-256.
[11]	LIU Lujun, LIU Zheng, LIU Renhui, LIU Yong. Grain Boundary Structure and Coercivity Enhancement of Nd₉₀Al₁₀ Alloy Modified NdFeB Permanent Magnets by GBD Process[J]. 金属学报, 2023, 59(11): 1457-1465.
[12]	WANG Jiangwei, CHEN Yingbin, ZHU Qi, HONG Zhe, ZHANG Ze. Grain Boundary Dominated Plasticity in Metallic Materials[J]. 金属学报, 2022, 58(6): 726-745.
[13]	CHEN Yang, MAO Pingli, LIU Zheng, WANG Zhi, CAO Gengsheng. Detwinning Behaviors and Dynamic Mechanical Properties of Precompressed AZ31 Magnesium Alloy Subjected to High Strain Rates Impact[J]. 金属学报, 2022, 58(5): 660-672.
[14]	ZENG Xiaoqin, WANG Jie, YING Tao, DING Wenjiang. Recent Progress on Thermal Conductivity of Magnesium and Its Alloys[J]. 金属学报, 2022, 58(4): 400-411.
[15]	LI Haiyong, LI Saiyi. Effect of Temperature on Migration Behavior of <111> Symmetric Tilt Grain Boundaries in Pure Aluminum Based on Molecular Dynamics Simulations[J]. 金属学报, 2022, 58(2): 250-256.

No Suggested Reading articles found!

Viewed

Full text

Abstract

Cited

Shared

Discussed