Microstructure and Mechanical Properties of Ti6Al4V Alloy by Laser Integrated Additive Manufacturing with Alternately Thermal/Mechanical Effects

doi:10.11900/0412.1961.2022.00011

Acta Metall Sin

2023, Vol. 59

Issue (1): 125-135 DOI: 10.11900/0412.1961.2022.00011

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Microstructure and Mechanical Properties of Ti6Al4V Alloy by Laser Integrated Additive Manufacturing with Alternately Thermal/Mechanical Effects

LU Haifei, LV Jiming, LUO Kaiyu, LU Jinzhong(

)

School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China

Cite this article:

LU Haifei, LV Jiming, LUO Kaiyu, LU Jinzhong. Microstructure and Mechanical Properties of Ti6Al4V Alloy by Laser Integrated Additive Manufacturing with Alternately Thermal/Mechanical Effects. Acta Metall Sin, 2023, 59(1): 125-135.

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Abstract

To meet the requirements of the long fatigue life and high reliability of the key components of the aeroengine as well as solve the challenges of “structure control” and “performance control” based on the fact that plastic deformation can effectively eliminate internal stress and close metallurgical defects generated by the thermal effect, a laser integrated additive manufacturing technology with alternately thermal/mechanical effects is developed. In this study, Ti6Al4V alloy was chosen as the research object. The distributions of residual stress and metallurgical defects and the microstructural evolution of the formed components were systematically studied. The effects of surface laser shock peening (LSP) and interlayer LSP without coating (LSPwC) treatments on mechanical properties were investigated using a tensile test. The results showed that after LSP, tensile residual stress was transformed into compressive residual stress. Additionally, laser shock waves could effectively improve the metallurgical defects in selective laser melting (SLM)-formed components. Moreover, high-density dislocation structures and numerous twins in two directions were produced in coarse α' martensite by laser shock waves, which jointly promoted the grain refinement of α' martensite. The ultimate tensile strength and elongation of Ti6Al4V fabricated by the laser integrated additive manufacturing technology with alternately thermal/mechanical effects reached 1543 MPa and 15.53%, which are 46.5% and 91.5% higher than those of the SLM-formed components, respectively, yielding a good combination of strength and ductility.

Key words: selective laser melting laser shock peening Ti6Al4V alloy residual stress microstructure mechanical property

Received: 11 January 2022

ZTFLH:

TG146

Fund: National Natural Science Foundation of China(52175409);National Natural Science Foundation of China(52175323);Jiangsu Provincial Science and Technology Projects in China(BE2021072);Jiangsu Provincial Science and Technology Projects in China(BE2022069-4)

About author: LU Jinzhong, professor, Tel: (0511)88797198, E-mail: jzlu@ujs.edu.cn

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	Haifei LU
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https://www.ams.org.cn/EN/10.11900/0412.1961.2022.00011 OR https://www.ams.org.cn/EN/Y2023/V59/I1/125

Fig.1 Schematics of selective laser melting (SLM) (a), laser shock peening (LSP) (b), the preparation of SLM and SLM-LSP specimens (c), and dimensions of tensile specimen (unit: mm) (d) (CAD—computer-aided design, LSPwC—laser shock peening without coating)

Fig.2 In-depth residual stress distributions of SLM and SLM-LSP specimens

Fig.3 Cross-setional OM images of SLM (a) and SLM-LSP (b) specimens (The dotted lines represent the interfaces between the third layer and second layer)

Fig.4 TEM images in the surface layer of SLM specimen
(a) acicular α' martensite
(b) magnified image of square region in Fig.4a and the corresponding SAED pattern (inset)
(c) mechanical twins (d) dislocation lines

Fig.5 TEM images in the surface layer of SLM-LSP specimen
(a) refined α' martensites
(b) a large number of parallel mechanical twins and high density dislocation structures
(c) magnified image of region Ⅰ in Fig.5b
(d) SAED pattern of region Ⅰ in Fig.5b showing {10

1 ˉ

1} twin (T—twin, M—martensite)
(e) magnified image of region Ⅱ in Fig.5b
(f) SAED pattern of region Ⅱ in Fig.5b showing {10

1 ˉ

2} twin

Fig.6 TEM analyses of dislocations in the surface layer of SLM-LSP specimen
(a, b) HRTEM image (a) and corresponding SEAD pattern (b)
(c) inverse fast Fourier-transform (IFFT) image of square region in Fig.6a
(d) atom arrangement on the (

10 1 ˉ 0

) plane
(e) atom arrangement on the (

10 1 ˉ 1

) plane
(f) atom arrangement on the (0001) plane

Fig.7 3D reconstruction graphs revealing 3D pore characteristics (a, c) and statistical results of the size and number of defects (b, d) for SLM specimen (a, b) and SLM-LSP specimen (c, d)

Fig.8 Engneering stress-strain curves of the tensile SLM and SLM-LSP specimens

Fig.9 SEM fracture morphologies of SLM (a, a₁, a₂) and SLM-LSP (b, b₁, b₂) specimens (B.D.—building direction)

1	Zhao Y Q, Xi Z P, Qu H L. Current situation of titanium alloy materials used for national aviation [J]. J. Aeronaut. Mater., 2003, 23(): 215
	赵永庆, 奚正平, 曲恒磊. 我国航空用钛合金材料研究现状 [J]. 航空材料学报, 2003, 23(suppl.) : 215
2	Machado A R, Wallbank J. Machining of titanium and its alloys—A review [J]. Proc. Inst. Mech. Eng., 1990, 204B: 53
3	Wang M, Lin X, Huang W. Laser additive manufacture of titanium alloys [J]. Mater. Technol., 2016, 31: 90
4	Liang Z Y, Zhang A F, Liang S D, et al. Research developments of high-performance titanium alloy by laser additive manufacturing technology [J]. Appl. Laser, 2017, 37: 452
	梁朝阳, 张安峰, 梁少端等. 高性能钛合金激光增材制造技术的研究进展 [J]. 应用激光, 2017, 37: 452
5	Mercelis P, Kruth J P. Residual stresses in selective laser sintering and selective laser melting [J]. Rapid Prototyp. J., 2006, 12: 254 doi: 10.1108/13552540610707013
6	Qiu C L, Panwisawas C, Ward M, et al. On the role of melt flow into the surface structure and porosity development during selective laser melting [J]. Acta Mater., 2015, 96: 72 doi: 10.1016/j.actamat.2015.06.004
7	Wu Z K, Wu S C, Zhang J, et al. Defect induced fatigue behaviors of selective laser melted Ti-6Al-4V via synchrotron radiation X-ray tomography [J]. Acta Metall. Sin., 2019, 55: 811 doi: 10.11900/0412.1961.2018.00408
	吴正凯, 吴圣川, 张杰等. 基于同步辐射X射线成像的选区激光熔化Ti-6Al-4V合金缺陷致疲劳行为 [J]. 金属学报, 2019, 55: 811 doi: 10.11900/0412.1961.2018.00408
8	Lv Y, Lei L Q, Sun L N. Influence of different combined severe shot peening and laser surface melting treatments on the fatigue performance of 20CrMnTi steel gear [J]. Mater. Sci. Eng., 2016, A658: 77
9	Chen A Y, Jia Y Q, Pan D, et al. Reinforcement of laser-welded stainless steels by surface mechanical attrition treatment [J]. Mater. Sci. Eng., 2013, A571: 161
10	Colegrove P A, Coules H E, Fairman J, et al. Microstructure and residual stress improvement in wire and arc additively manufactured parts through high-pressure rolling [J]. J. Mater. Process. Technol., 2013, 213: 1782 doi: 10.1016/j.jmatprotec.2013.04.012
11	Fan Y J, Zhao X H, Liu Y. Research on fatigue behavior of the flash welded joint enhanced by ultrasonic peening treatment [J]. Mater. Des., 2016, 94: 515 doi: 10.1016/j.matdes.2016.01.070
12	Hatamleh O. A comprehensive investigation on the effects of laser and shot peening on fatigue crack growth in friction stir welded AA 2195 joints [J]. Int. J. Fatigue, 2009, 31: 974 doi: 10.1016/j.ijfatigue.2008.03.029
13	Montross C S, Wei T, Lin Y, et al. Laser shock processing and its effects on microstructure and properties of metal alloys: A review [J]. Int. J. Fatigue, 2002, 24: 1021 doi: 10.1016/S0142-1123(02)00022-1
14	Gao Y K. Influence of different surface modification treatments on surface integrity and fatigue performance of TC4 titanium alloy [J]. Acta Metall. Sin., 2016, 52: 915
	高玉魁. 不同表面改性强化处理对TC4钛合金表面完整性及疲劳性能的影响 [J]. 金属学报, 2016, 52: 915 doi: 10.11900/0412.1961.2015.00628
15	Dorman M, Toparli M B, Smyth N, et al. Effect of laser shock peening on residual stress and fatigue life of clad 2024 aluminium sheet containing scribe defects [J]. Mater. Sci. Eng., 2012, A548: 142
16	Luo K Y, Jing X, Sheng J, et al. Characterization and analyses on micro-hardness, residual stress and microstructure in laser cladding coating of 316L stainless steel subjected to massive LSP treatment [J]. J. Alloys Compd., 2016, 673: 158 doi: 10.1016/j.jallcom.2016.02.266
17	Kalentics N, Boillat E, Peyre P, et al. Tailoring residual stress profile of selective laser melted parts by laser shock peening [J]. Addit. Manuf., 2017, 16: 90
18	Luo S H, He W F, Chen K, et al. Regain the fatigue strength of laser additive manufactured Ti alloy via laser shock peening [J]. J. Alloys Compd., 2018, 750: 626 doi: 10.1016/j.jallcom.2018.04.029
19	Sun R J, Li L H, Zhu Y, et al. Microstructure, residual stress and tensile properties control of wire-arc additive manufactured 2319 aluminum alloy with laser shock peening [J]. J. Alloys Compd., 2018, 747: 255 doi: 10.1016/j.jallcom.2018.02.353
20	Chi J X, Cai Z Y, Wan Z D, et al. Effects of heat treatment combined with laser shock peening on wire and arc additive manufactured Ti17 titanium alloy: Microstructures, residual stress and mechanical properties [J]. Surf. Coat. Technol., 2020, 396: 125908 doi: 10.1016/j.surfcoat.2020.125908
21	Guo W, Sun R J, Song B W, et al. Laser shock peening of laser additive manufactured Ti6Al4V titanium alloy [J]. Surf. Coat. Technol., 2018, 349: 503 doi: 10.1016/j.surfcoat.2018.06.020
22	Chi J X, Cai Z Y, Zhang H P, et al. Combining manufacturing of titanium alloy through direct energy deposition and laser shock peening processes [J]. Mater. Des., 2021, 203: 109626 doi: 10.1016/j.matdes.2021.109626
23	Lan L, Jin X Y, Gao S, et al. Microstructural evolution and stress state related to mechanical properties of electron beam melted Ti-6Al-4V alloy modified by laser shock peening [J]. J. Mater. Sci. Technol., 2020, 50: 153 doi: 10.1016/j.jmst.2019.11.039
24	Jin X Y, Lan L, Gao S, et al. Effects of laser shock peening on microstructure and fatigue behavior of Ti-6Al-4V alloy fabricated via electron beam melting [J]. Mater. Sci. Eng., 2020, A780: 139199
25	Peyre P, Carboni C, Forget P, et al. Influence of thermal and mechanical surface modifications induced by laser shock processing on the initiation of corrosion pits in 316L stainless steel [J]. J. Mater. Sci., 2007, 42: 6866 doi: 10.1007/s10853-007-1502-4
26	Kalentics N, Boillat E, Peyre P, et al. 3D laser shock peening—A new method for the 3D control of residual stresses in selective laser melting [J]. Mater. Des., 2017, 130: 350 doi: 10.1016/j.matdes.2017.05.083
27	Kalentics N, Sohrabi N, Tabasi H G, et al. Healing cracks in selective laser melting by 3D laser shock peening [J]. Addit. Manuf., 2019, 30: 100881
28	Kalentics N, de Seijas M O V, Griffiths S, et al. 3D Laser shock peening—A new method for improving fatigue properties of selective laser melted parts [J]. Addit. Manuf., 2020, 33: 101112
29	Bartlett J L, Li X D. An overview of residual stresses in metal powder bed fusion [J]. Addit. Manuf., 2019, 27: 131 doi: 10.1016/j.addma.2019.02.020
30	Lu J Z, Wu L J, Sun G F, et al. Microstructural response and grain refinement mechanism of commercially pure titanium subjected to multiple laser shock peening impacts [J]. Acta Mater., 2017, 127: 252 doi: 10.1016/j.actamat.2017.01.050
31	Cloots M, Uggowitzer P J, Wegener K. Investigations on the microstructure and crack formation of IN738LC samples processed by selective laser melting using Gaussian and doughnut profiles [J]. Mater. Des., 2016, 89: 770 doi: 10.1016/j.matdes.2015.10.027
32	Liu X Q, Tan C W, Zhang J, et al. Influence of microstructure and strain rate on adiabatic shearing behavior in Ti-6Al-4V alloys [J]. Mater. Sci. Eng., 2009, A501: 30
33	Leuders S, Thöne M, Riemer A, et al. On the mechanical behaviour of titanium alloy TiAl6V4 manufactured by selective laser melting: Fatigue resistance and crack growth performance [J]. Int. J. Fatigue, 2013, 48: 300 doi: 10.1016/j.ijfatigue.2012.11.011
34	Sanaty-Zadeh A. Comparison between current models for the strength of particulate-reinforced metal matrix nanocomposites with emphasis on consideration of Hall-Petch effect [J]. Mater. Sci. Eng., 2012, A531: 112
35	Lu K, Lu L, Suresh S. Strengthening materials by engineering coherent internal boundaries at the nanoscale [J]. Science, 2009, 324: 349 doi: 10.1126/science.1159610 pmid: 19372422
36	Wang C L, Yu D P, Niu Z Q, et al. The role of pyramidal <c + a> dislocations in the grain refinement mechanism in Ti-6Al-4V alloy processed by severe plastic deformation [J]. Acta Mater., 2020, 200: 101 doi: 10.1016/j.actamat.2020.08.076
37	Liu W H, Wu Y, He J Y, et al. Grain growth and the Hall-Petch relationship in a high-entropy FeCrNiCoMn alloy [J]. Scr. Mater., 2013, 68: 526 doi: 10.1016/j.scriptamat.2012.12.002
38	Tian X N, Zhu Y M, Lim C V S, et al. Isotropic and improved tensile properties of Ti-6Al-4V achieved by in-situ rolling in direct energy deposition [J]. Addit. Manuf., 2021, 46: 102151
39	Vandenbroucke B, Kruth J P. Selective laser melting of biocompatible metals for rapid manufacturing of medical parts [J]. Rapid Prototyp. J., 2007, 13: 196 doi: 10.1108/13552540710776142
40	Lv J M, Luo K Y, Lu H F, et al. Achieving high strength and ductility in selective laser melting Ti-6Al-4V alloy by laser shock peening [J]. J. Alloys Compd., 2022, 899: 163335 doi: 10.1016/j.jallcom.2021.163335
41	Lu H F, Wu L J, Wei H L, et al. Microstructural evolution and tensile property enhancement of remanufactured Ti6Al4V using hybrid manufacturing of laser directed energy deposition with laser shock peening [J]. Addit. Manuf., 2022, 55: 102877

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