In this study, the microstructure and tensile behaviour of pure titanium processed by means of high-energy shot peening have been studied. The results show that a nanocrystalline surface layer is prepared on the surface of pure titanium. During severe deformation, the dislocations, twins and slip bands with single orientation are formed first, then the intersections of twins and slip bands are observed, and then the subgrains appear near or in the slip bands and finally the randomly oriented nano-grains are formed due to the further breakdown. After high-energy shot peening, the ultimate tensile strength and the yield strength increase by 27 and 40%, while the elongation decreases by 64% after treatment, due to the increasing dislocation density, micro-strain and the grain refinement.
LiuH. N. and WebsterT. J.: ‘Nanomedicine for implants: a review of studies and necessary experimental tools’, Biomaterials, 2007, 28, 354–369. doi: 10.1016/j.biomaterials.2006.08.049
2.
MisraR. D. K., NuneC., PesacretaT. C., SomaniM. C. and KarjalainenL. P.: ‘Understanding the impact of grain structure in austenitic stainless steel from a nanograined regime to a coarse-grained regime on osteoblast functions using a novel metal deformation–annealing sequence’, Acta Biomater., 2013, 9, 6245–6258. doi: 10.1016/j.actbio.2012.12.003
3.
SahooR., JhaB. B. and SahooT. K.: ‘Effect of primary alpha phase variation on mechanical behavior of Ti–6Al–4V alloy’, Mater. Sci. Technol., 2015, 31, 1486–1494. doi: 10.1179/1743284714Y.0000000736
4.
ThorfveA., PalmquistA. and GrandfieldK.: ‘Three-dimensional analytical techniques for evaluation of osseointegrated titanium implants’, Mater. Sci. Technol., 2015, 31, 174–179. doi: 10.1179/1743284714Y.0000000687
5.
LuK. and LuJ.: ‘Nanostructured surface layer on metallic materials induced by surface mechanical attrition treatment’, Mater. Sci. Eng. A, 2004, 375, 38–45. doi: 10.1016/j.msea.2003.10.261
6.
UnalO. and VarolR.: ‘Surface severe plastic deformation of AISI 304 viaconventional shot peening, severe shot peening and repeening’, Appl. Surf. Sci., 2015, 351, 289–295. doi: 10.1016/j.apsusc.2015.05.093
7.
BagherifardS. and GuanglianoM.: ‘Fatigue behavior of a low-alloy steel with nanostructured surface obtained by severe shot peening’, Eng. Fract. Mech., 2012, 81, 56–68. doi: 10.1016/j.engfracmech.2011.06.011
8.
ZhuK. Y., VasselA., BrissetF., LuK. and LuJ.: ‘Nanostructure formation mechanism of α-titanium using SMAT’, Acta Mater., 2004, 52, 4101–4110. doi: 10.1016/j.actamat.2004.05.023
9.
WenM., LiuG., GuJ. F., GuanW. M. and LuJ.: ‘Dislocation evolution in titanium during surface severe plastic deformation’, Appl. Surf. Sci., 2009, 255, 6097–6102. doi: 10.1016/j.apsusc.2009.01.048
10.
BalasundaramG. and WebsterT. J.: ‘An overview of nano-polymers for orthopedic applications’, Macromol. Biosci., 2007, 7, 635–642. doi: 10.1002/mabi.200600270
11.
WebsterT. J., HellenmeyerE. L. and PriceR. L.: ‘Increased osteoblast functions on theta+deltananofiber alumina’, Biomaterials, 2005, 26, 953–960. doi: 10.1016/j.biomaterials.2004.03.040
12.
WebsterT. J. and EjioforJ. U.: ‘Increased osteoblast adhesion on nanophase metals: Ti, Ti6Al4V, and CoCrMo’, Biomaterials, 2004, 25, 4731–4739. doi: 10.1016/j.biomaterials.2003.12.002
13.
WangZ., LuanW. Z., HuangJ. J. and JiangC. H.: ‘X-ray diffraction line profile analysis of iron ball milled powders’, Mater. Sci. Eng. A, 2004, 366, 229–238. doi: 10.1016/S0921-5093(03)00572-0
14.
GoncalvesN. S., CarvalhoJ. A., LimaZ. M. and SasakJ. M.: ‘Size-strain study of NiO nanoparticles by X-ray powder diffraction line broadening’, Mater. Lett., 2012, 72, 36–38. doi: 10.1016/j.matlet.2011.12.046
15.
MajzoobiG. H. and AhmadkhaniA. R.: ‘The effects of multiple re-shot peening on fretting fatigue behavior of Al7075–T6’, Surf. Coat. Technol., 2010, 205, 102–109. doi: 10.1016/j.surfcoat.2010.06.014
16.
LiuW. B., ZhangC., YangZ. G. and XiaZ. X.: ‘Microstructure and thermal stability of bulk nanocrystalline alloys produced by surface mechanical attrition treatment’, Appl. Sur. Sci., 2014, 292, 556–562. doi: 10.1016/j.apsusc.2013.12.008
17.
UnalO., Cahit KaraoglanliA., VarolR. and KobayashiA.: ‘Microstructure evolution and mechanical behavior of severe shot peened commercially pure titanium’, Vacuum, 2014, 110, 202–206. doi: 10.1016/j.vacuum.2014.08.004
18.
ChanH. L., RuanH. H., ChenA. Y. and LuJ.: ‘Optimization of the strain rate to achieve exceptional mechanical properties of 304 stainless steel using high speed ultrasonic surface mechanical attrition treatment’, Acta Mater., 2010, 58, 5086–5096. doi: 10.1016/j.actamat.2010.05.044
19.
WenM., GuJ. F., LiuG., WangZ. B. and LuJ.: ‘Formation of nanoporous titania on bulk titanium by hybrid surface mechanical attrition treatment’, Surf. Coat. Technol., 2007, 201, 6285–6289. doi: 10.1016/j.surfcoat.2006.11.031
20.
FengQ., JiangC., XuZ., XieL. and JiV.: ‘Effect of shot peening on the residual stress and microstructure of duplex stainless steel’, Surf. Coat. Technol., 2013, 226, 140–144. doi: 10.1016/j.surfcoat.2013.03.047
21.
XieL., JiangC. and LuW.: ‘The influence of shot peening on the surface properties of (TiB+TiC)/Ti–6Al–4V’, Appl. Surf. Sci., 2013, 280, 981–988. doi: 10.1016/j.apsusc.2013.05.135
22.
ShinD. H., KimI., KimJ., KimY. S. and SemiatinS. L.: ‘Microstructure development during equal-channel angular pressing of titanium’, Acta Mater., 2003, 51, 983–986. doi: 10.1016/S1359-6454(02)00501-3
23.
MunroeN. and TanX. L.: ‘Orientation dependence of slip and twinning in HCP metals’, Scripta Mater., 1997, 36, 1383–1386. doi: 10.1016/S1359-6462(97)00048-1
24.
WangL. M., WangZ. B., GuoS. and LuK.: ‘Annealing-induced grain refinement in a nanostructured ferritic steel’, J. Mater. Sci. Technol., 2012, 28, 41–45. doi: 10.1016/S1005-0302(12)60021-8
25.
BagherifardS., Fernandez-ParienteI., GhelichiR. and GuaglianoM.: ‘Effect of severe shot peening on microstructure and fatigue strength of cast iron’, Int. J. Fatigue, 2014, 65, 64–70. doi: 10.1016/j.ijfatigue.2013.08.022
26.
YangD. K., CizekP. and HodgsonP. D.: ‘On the deformation mechanism of ultrafine-grained titanium with multilayered hierarchical structure’, Mater. Sci. Eng. A, 2013, 582, 162–169. doi: 10.1016/j.msea.2013.06.019
27.
LuJ., ChanH. L., ChenA. Y. and KouH. N.: ‘Mechanics of high strength and high ductility materials’, Procedia Eng., 2011, 10, 2202–2207. doi: 10.1016/j.proeng.2011.04.364
28.
KimH. Y., SasakiT., OkutsuK., KimJ. I., InamuraT., HosodaH. and MiyazakiS.: ‘Texture and shape memory behavior of Ti–22Nb–6Ta alloy’, Acta Mater., 2006, 54, 423–433. doi: 10.1016/j.actamat.2005.09.014
