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Acta Metall Sin  2019, Vol. 55 Issue (6): 692-700    DOI: 10.11900/0412.1961.2019.00007
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Microstructure and Tensile Property of TC4 Alloy Produced via Electron Beam Rapid Manufacturing
Zheng LIU1,2,Jianrong LIU1(),Zibo ZHAO1,Lei WANG1,Qingjiang WANG1,Rui YANG1
1. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
2. School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
Cite this article: 

Zheng LIU,Jianrong LIU,Zibo ZHAO,Lei WANG,Qingjiang WANG,Rui YANG. Microstructure and Tensile Property of TC4 Alloy Produced via Electron Beam Rapid Manufacturing. Acta Metall Sin, 2019, 55(6): 692-700.

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Abstract  

Electron beam rapid manufacturing (EBRM) is one of the 3D printing technologies. The main attractions of EBRM technology are its high efficiency and economy in fabricating large, complex near net shape components dielessly and only needing limited machining. In general, the microstructure and texture of titanium alloy can play a significant role in determining its mechanical behaviors. In the present work, the microstructure, texture and tensile property of TC4 alloy produced by electron beam rapid manufacturing (EBRM) are investigated. Results show that the microstructure is comprised of columnar prior β grains that orient parallel to the building direction. The width of the columnar β grains increased rapidly at the initial several build layers, and the subsequent increase rate of the width of the columnar β grains tends to slow down. Fine α lamellae with gradient size are observed inside the columnar prior β grains, which occur because the alloy experiences different complex thermal histories during the EBRM-produced process. The size of α lamellae tends to decrease with the increase of build layers. The XRD result shows that the TC4 alloy has a typical α phase texture, (the c-axes are either concentrated at about 45° or are perpendicular to the building direction). At the same time, the <$10\bar{1}0$> poles are relative to random distribution. For the tensile samples along the electron beam scanning direction, the yield strengths do not show significant change with the increase of build layers, but the tensile strengths increase. The ductility of the alloy also has an upward trend, despite of a slightly decreasing ductility in the top sample. The tensile samples at the bottom of the alloy (10 mm and 20 mm away from the substrate) have similar work hardening exponents, which are lower than the top sample. The top sample shows the highest work hardening exponent. This difference in the tensile properties can be highly attributed to the gradient microstructure. The alloy also presents obvious anisotropy in tensile strength. The tensile sample along the 45° direction has a higher strength than the sample along the X direction, while the tensile sample along the Z direction shows the lowest strength. This anisotropic strength is strongly associated with the α phase texture. When the loading direction is 45° to the building direction, most of the c-axes of α phase are about parallel to the loading direction, showing a "hard" orientation, leading to a higher strength than other oriented samples. Conversely, when the loading direction is along the building direction, most of the α phase present a "soft" orientation, resulting in lower strength compared to the tensile samples along the 45° or the X direction.

Key words:  EBRM      TC4 alloy      microstructure      texture      tensile property     
Received:  09 January 2019     
ZTFLH:  TG14  
Fund: National Key Research and Development Program of China(No.2017YFB1103100);AVIC Science Foundation of China(No.20175492002)

URL: 

https://www.ams.org.cn/EN/10.11900/0412.1961.2019.00007     OR     https://www.ams.org.cn/EN/Y2019/V55/I6/692

Fig.1  Schematics of the TC4 alloy produced by electron beam rapid manufacturing (EBRM) (a) and sampling location of tensile specimens (b) (X direction is the electron beam scanning direction, Z direction is the building direction)
Fig.2  OM images of substrate and bottom (a), and top (b) of the TC4 alloy produced by EBRM in the X-Z plane (Inset show the high magnified image of square area)
Fig.3  The changes of the prior β grain size and the width of α lath along the building height
Fig.4  SEM images of bottom (a), middle (b) and top (c) of the TC4 alloy produced by EBRM
Fig.5  Pole figures of {0001} (a) and {101ˉ0} (b) for the α phase in the TC4 alloy
Fig.6  Tensile properties of samples along the X direction at different Z direction height
Fig.7  True stress-true stain curves plotted on logarithmic axes in plastic portion between 2.5% and 4.6% strain for the tensile samples at different Z direction height and work hardening exponent (σ—true stress, ε—true strain, n—work hardening exponent)
Fig.8  TEM images of bottom (a), middle (b) and top (c) of the TC4 alloy produced by EBRM
  
Fig.10  Schematics of slip length along three different loading directions
Fig.11  Inverse pole figures of TC4 alloy along X direction (a), 45° angle to X direction (b) and Z direction (c) (The black and blue contour lines are the Schmid's factors for basal and prismatic slip in orientation triangle, respectively)
[1] Liu Z, Qin Z X, Liu F, et al. The microstructure and mechanical behaviors of the Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy produced by laser melting deposition [J]. Mater. Charact., 2014, 97: 132
[2] Lu S L, Qian M, Tang H P, et al. Massive transformation in Ti-6Al-4V additively manufactured by selective electron beam melting [J]. Acta Mater., 2016, 104: 303
[3] Tan X P, Kok Y, Tan Y J, et al. Graded microstructure and mechanical properties of additive manufactured Ti-6Al-4V via electron beam melting [J]. Acta Mater., 2015, 97: 1
[4] Thijs L, Verhaeghe F, Craeghs T, et al. A study of the microstructural evolution during selective laser melting of Ti-6Al-4V [J]. Acta Mater., 2010, 58: 3303
[5] Banerjee D, Williams J C. Perspectives on titanium science and technology [J]. Acta Mater., 2013, 61: 844
[6] Liu Z, Zhao Z B, Liu J R, et al. Distinct dendritic α phase emerging on the surface of primary α phase in a compressed near-α titanium alloy [J]. J. Mater. Sci. Technol., 2018, 34: 666
[7] Zhao Z B, Wang Q J, Hu Q M, et al. Effect of β (110) texture intensity on α-variant selection and microstructure morphology during βα phase transformation in near α titanium alloy [J]. Acta Mater., 2017, 126: 372
[8] Zhao Z B, Wang Q J, Liu J R, et al. Effect of heat treatment on the crystallographic orientation evolution in a near-α titanium alloy Ti60 [J]. Acta Mater., 2017, 131: 305
[9] Hrabe N, Quinn T. Effects of processing on microstructure and mechanical properties of a titanium alloy (Ti-6Al-4V) fabricated using electron beam melting (EBM), Part 1: Distance from build plate and part size [J]. Mater. Sci. Eng., 2013, A573: 264
[10] Hrabe N, Quinn T. Effects of processing on microstructure and mechanical properties of a titanium alloy (Ti-6Al-4V) fabricated using electron beam melting (EBM), Part 2: Energy input, orientation, and location [J]. Mater. Sci. Eng., 2013, A573: 271
[11] Xu W, Lui E W, Pateras A, et al. In situ tailoring microstructure in additively manufactured Ti-6Al-4V for superior mechanical performance [J]. Acta Mater., 2017, 125: 390
[12] Carroll B E, Palmer T A, Beese A M. Anisotropic tensile behavior of Ti-6Al-4V components fabricated with directed energy deposition additive manufacturing [J]. Acta Mater., 2015, 87: 309
[13] Liu Z, Zhao Z B, Liu J R, et al. Effect of α texture on the tensile deformation behavior of Ti-6Al-4V alloy produced via electron beam rapid manufacturing [J]. Mater. Sci. Eng., 2019, A742: 508
[14] Suo H B, Chen Z Y, Liu J R, et al. Microstructure and mechanical properties of Ti-6Al-4V by electron beam rapid manufacturing [J]. Rare Met. Mater. Eng., 2014, 43: 780
[15] Wang Y N, Huang J C. Texture analysis in hexagonal materials [J]. Mater. Chem. Phys., 2003, 81: 11
[16] Li W Y, Chen Z Y, Liu J R, et al. Effect of texture on anisotropy at 600 ℃ in a near-α titanium alloy Ti60 plate [J]. Mater. Sci. Eng., 2017, A688: 322
[17] Li W Y, Chen Z Y, Liu J R, et al. Rolling texture and its effect on tensile property of a near-α titanium alloy Ti60 plate [J]. J. Mater. Sci. Technol., 2019, 35: 790
[18] Al-Bermani S S, Blackmore M L, Zhang W, et al. The origin of microstructural diversity, texture, and mechanical properties in electron beam melted Ti-6Al-4V [J]. Metall. Mater. Trans., 2010, 41A: 3422
[19] Antonysamy A A, Meyer J, Prangnell P B. Effect of build geometry on the β-grain structure and texture in additive manufacture of Ti-6Al-4V by selective electron beam melting [J]. Mater. Charact., 2013, 84: 153
[20] Waryoba D R, Keist J S, Ranger C, et al. Microtexture in additively manufactured Ti-6Al-4V fabricated using directed energy deposition [J]. Mater. Sci. Eng., 2018, A734: 149
[21] Shi R, Dixit V, Fraser H L, et al. Variant selection of grain boundary α by special prior β grain boundaries in titanium alloys [J]. Acta Mater., 2014, 75: 156
[22] Bantounas I, Dye D, Lindley T C. The role of microtexture on the faceted fracture morphology in Ti-6Al-4V subjected to high-cycle fatigue [J]. Acta Mater., 2010, 58: 3908
[23] Bridier F, Villechaise P, Mendez J. Analysis of the different slip systems activated by tension in a α/β titanium alloy in relation with local crystallographic orientation [J]. Acta Mater., 2005, 53: 555
[24] Li H, Boehlert C J, Bieler T R, et al. Analysis of slip activity and heterogeneous deformation in tension and tension-creep of Ti-5Al-2.5Sn (wt %) using in-situ SEM experiments [J]. Philos. Mag., 2012, 92: 2923
[25] Li H, Boehlert C J, Bieler T R, et al. Examination of the distribution of the tensile deformation systems in tension and tension-creep of Ti-6Al-4V (wt.%) at 296 K and 728 K [J]. Philos. Mag., 2015, 95: 691
[26] Li H, Mason D E, Yang Y, et al. Comparison of the deformation behaviour of commercially pure titanium and Ti-5Al-2.5Sn (wt.%) at 296 and 728 K [J]. Philos. Mag., 2013, 93: 2875
[27] Hayes B J, Martin B W, Welk B, et al. Predicting tensile properties of Ti-6Al-4V produced via directed energy deposition [J]. Acta Mater., 2017, 133: 120
[28] Warwick J L W, Jones N G, Bantounas I, et al. In situ observation of texture and microstructure evolution during rolling and globularization of Ti-6Al-4V [J]. Acta Mater., 2013, 61: 1603
[29] Hirsch P B, Mitchell T E. Stage II work hardening in crystals [J]. Can. J. Phys., 1967, 45: 663
[30] Suri S, Viswanathan G B, Neeraj T, et al. Room temperature deformation and mechanisms of slip transmission in oriented single-colony crystals of an α/β titanium alloy [J]. Acta Mater., 1999, 47: 1019
[31] Ren Y M, Lin X, Fu X, et al. Microstructure and deformation behavior of Ti-6Al-4V alloy by high-power laser solid forming [J]. Acta Mater., 2017, 132: 82
[32] Tang Q. Research on defects formation mechanism of titanium alloy in electron beam freeform fabrication [D]. Wuhan: Huazhong University of Science and Technology, 2015
[32] (汤 群. 钛合金电子束快速成形缺陷形成机理研究 [D]. 武汉: 华中科技大学, 2015)
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