Phase transformations during hot rolling is determined for the forged and β heat treated TC21 titanium alloys. The results show that β heat treatment has a great effect on phase constitution. Three types of precipitates, namely, α2, ω and (Ti, Zr)5Si3 phase is observed in the rolled forged materials, whereas the rolled β heat treated materials exhibites the presence of lamellar α and type 2α precipitate. The influence of β heat treatment on the phase transformations has been discussed on the basis of alloying elements, and β heat treatment can eliminate or decrease elemental segregation.
ZhuY. C., ZengW. D., LiuJ. L., ZhaoY. Q. and YuH. Q.: ‘Effect of processing parameters the deformation behavior of as-cast TC21 titanium alloy’, Mater. Des., 2012, 33, 264–272. doi: 10.1016/j.matdes.2011.07.018
2.
WangL. R., ZhaoY. Q. and ZhouL.: ‘Effect of hot rolling on the structure TC21 alloy with acicular alpha’, Mater. Manuf. Processes, 2012, 27, 154–159. doi: 10.1080/10426914.2011.566662
3.
SemiatinS. L., SeetharamanV. and WeissI.: ‘The thermomechanical processing of alpha/beta titanium alloys’, JOM, 1997, 49, 33–38. doi: 10.1007/BF02914711
4.
ChaoQ., HodgsonP. D. and BeladiH.: ‘Ultrafine grain formation in a Ti–6Al–4V alloy by thermomechanical processing of a martensitic microstructure’, Metall. Mater. Trans. A, 2014, 45A, 2659–2671. doi: 10.1007/s11661-014-2205-5
5.
ZherebtsovS., MazurA., SalishchevG. and LojkowskiW.: ‘Effect of hydrostatic extrusion at 600–700°C on the structure and properties of Ti–6AL–4V alloy’, Mater. Sci. Eng. A, 2008, A485, 39–45. doi: 10.1016/j.msea.2007.08.081
6.
ParkC. H., KimJ. H., YeomJ.-T., OhC.-S., SemiatinS. L. and LeeC. S.: ‘Formation of a submicrocrystalline structure in a two-phase titanium alloy without severe plastic deformation’, Scr. Mater., 2013, 68, 996–999. doi: 10.1016/j.scriptamat.2013.02.055
7.
PrasadK. and VarmaV. K.: ‘Serrated flow behavior in a near alpha titanium alloy IMI 834’, Mater. Sci. Eng. A, 2008, A486, 158–166. doi: 10.1016/j.msea.2007.09.020
8.
CrawforthP., WynneB., TurnerS. and JacksonM.: ‘Subsurface deformation during precision turning of near-alpha titanium alloy’, Scr. Mater., 2012, 67, 842–845. doi: 10.1016/j.scriptamat.2012.08.001
9.
HamoudaG.: ‘Microstructure and fatigue crack growth mechanisms in high temperature titanium alloys’, Int. J. Fatigue, 2010, 32, 1448–1460. doi: 10.1016/j.ijfatigue.2010.02.001
10.
JanaŠ., MilosJ., HarcubaP. and StraskyJ.: ‘Ageing study of Ti metal LCB titanium alloy’, Metal, 2013, 5, (15–17), 1536–1540.
11.
DangW., XueX., KouH., ChangH., LiJ., ZhangF. and ZhouL.: ‘Phase and microstructure of TC21 titanium alloy during slow cooling’, J. Aeronaut. Mater., 2010, 30, (3), 19–23.
12.
WangY., KouH., ZhouZ. and LiJ.: ‘Study on phase transformation of TC21 alloy during aging treatment’, Mater. Heat Treat., 2010, 30, (1) 132–135.
13.
ZhuZ., WangX., TongL. and LiuD.: ‘Phase transformation and composition for novel TC21’, Rare Met. Lett., 2006, 25, (12), 23–27.
14.
FeiY., ZhouL., QuH., ZhaoY. and HuangC.: ‘The phase and microstructure of TC21 alloy’, Mater Sci. Eng. A, 2008, A494, 166–172. doi: 10.1016/j.msea.2008.04.017
15.
KimJ. H., SemiatinS. L. and LeeC. S.: ‘High-temperature deformation and grain-boundary characteristics of titanium alloys with an equiaxed microstructure’, Mater. Sci. Eng. A, 2008, A485, 601–612. doi: 10.1016/j.msea.2007.08.027
16.
BanerjeeD., SheltonC. G., RalphB. and WilliamsJ. C.: ‘A resolution of the interface phase problem in titanium alloys’, Acta Metall., 1988, 36, (1), 125–141. doi: 10.1016/0001-6160(88)90033-8
17.
NagS., BanerjeeR., SrinivasanR., HwangJ. Y., HarperM. and FraserH. L.: ‘ω-Assisted nucleation and growth of α precipitates in the Ti–5Al–5Mo–5V–3Cr–0.5Fe β titanium alloy’, Acta Mater, 2009, 57, 2136–2147. doi: 10.1016/j.actamat.2009.01.007
18.
YanM., DarguschM. S., EbelT. and QianM.: ‘A transmission electron microscopy and three-dimensional atom probe study of the oxygen-induced fine microstructural features in as-sintered Ti–6Al–4V and their impacts on ductility’, Acta Mater., 2014, 68, 196–206. doi: 10.1016/j.actamat.2014.01.015
19.
HuangA. J., LiG. P. and YangR.: ‘Acicular α2 precipitation induced by capillarity at α/β phase boundaries in Ti–14Al–2Zr–3Sn–3Mo–0.5Si titanium alloy’, Acta Mater., 2003, 51, 4939–4952. doi: 10.1016/S1359-6454(03)00352-5
20.
ZhangJ. and LiD.: ‘α2 ordered phase in high temperature titanium alloys’; 2002, Shenyang, China, Northeastern University Press.
21.
ZhangX. D., WiezorekJ. M. K., EvansW. A.III, BaeslackD. J. and FraserH. L.: ‘Precipitation of ordered α2 phase in Ti–6–22–22 alloy’, Acta Metall., 1998, 46, (13), 4485–4495.
22.
SemiatinS. L. and McQuayP. A.: ‘Segregation and β heat of a near-gamma titanium aluminide’, Metall. Trans. A, 1992, 23A, (1), 149–161. doi: 10.1007/BF02660861
23.
WilliamsJ. C., HickmanB. S. and LeslieD. H.: ‘The effect of ternary additions on the decomposition of metastable beta-phase titanium alloys’, Metall. Trans., 1971, 2, 477–484. doi: 10.1007/BF02663337
24.
DevarajA.: ‘Phase separation and second phase precipitation in beta titanium alloys’, PhD thesis, University of North Texas, Denton, TX, USA; 2011.
25.
GuY., ZengF., QiY., XiaC. and XiongX.: ‘Tensile creep behavior of heat-treated TC11 titanium alloy at 450–550°C’, Mater Sci. Eng. A, 2013, A55, 74–85. doi: 10.1016/j.msea.2013.03.038
26.
PopovA., RossinaN. and PopovaM.: ‘The effect of alloying on the ordering processes in near-alpha titanium alloys’, Mater. Sci. Eng. A, 2013, A564, 284–287. doi: 10.1016/j.msea.2012.11.043
27.
BulanovaM., FirstovS., GornayaI. and MiracleD.: ‘The melting diagram of the Ti-corner of the Ti–Zr–Si system and mechanical properties of as-cast compositions’, J. Alloys Compd, 2004, 384, 106–114. doi: 10.1016/j.jallcom.2004.02.060
28.
SalpadoruN. H. and FlowerH. M.: ‘Phase equilibria and transformations in a Ti–Zr–Si system’, Metall. Mater. Trans. A, 1995, 26A, 243–257. doi: 10.1007/BF02664663