Friction stir welding is a solid state, environment friendly and energy efficient welding process for joining many engineering alloys including magnesium alloys. In this study, the effect of different cooling rates on microstructural and mechanical properties of friction stir welded AZ91C magnesium alloy was investigated. AZ91C magnesium samples were friction stir welded in air as well as in water. The effects of submerging environment on tensile and hardness properties of samples were discussed. The results showed that water, as a welding environment, has a considerable impact on the mechanical properties of the weld.
MordikeB. L. and EbertT.: ‘Magnesium properties – applications – potential’, Mater. Sci. Eng. A, 2001, A302, 37–46. doi: 10.1016/S0921-5093(00)01351-4
4.
WatanabeH., MukaiT., MabuchiM. and HigashiK.: ‘Deformation mechanism of fine-grained superplasticity in metallic materials expected from the phenomenological constitutive equation’, Acta Mater., 2001, 49, 2027–2037. doi: 10.1016/S1359-6454(01)00101-X
5.
ChenC. Y. and TsaoY. A.: ‘On the hardening of friction stir processed Mg-AZ31 based composites with 5–20% nano-ZrO2 and nano-SiO2 particles’, Mater. Sci. Eng. A, 2004, A383, 21–29.
6.
ThomasW. M., NicholasE. D., NeedhamJ. C., MurchM. G., TempleS. P. and DawesC. J.: ‘Improvements relating to friction welding’, G.B. patent no. 9125978.8; 1991.
7.
FranchiA. S., FernandeF. F. and TravessaD. N.: ‘Microstructural aspects and mechanical properties of friction stir welded AA2024-T3 aluminum alloy sheet’, Mater. Des., 2011, 32, 4684–4688. doi: 10.1016/j.matdes.2011.06.055
8.
SinghR. K. R., SharmaC., DwivediD. K., MehtaN. K. and KumarP.: ‘The microstructure and mechanical properties of friction stir welded Al–Zn–Mg alloy in as welded and heat threaded conditions’, Mater. Des., 2011, 32, 682–687. doi: 10.1016/j.matdes.2010.08.001
9.
DobriyalR. P., DhindawB. K., MuthukumaranS. and MukherjeeS. K.: ‘Microstructure and properties of friction stir butt-welded AE42 magnesium alloy’, Mater. Sci. Eng. A, 2008, A477, 243–249. doi: 10.1016/j.msea.2007.06.028
10.
FranchiA. S., FernandeF. F. and TravessaD. N.: ‘Microstructural aspects and mechanical properties of friction stir welded AA2024-T3 aluminum alloy sheet’, J. Mater. Des., 2011, 32, 4684–4688. doi: 10.1016/j.matdes.2011.06.055
11.
LeeW.-B., LeeC.-Y., KimM.-K., YoonJ.-I., KimY.-J., YoenY.-M. and JungS.-B.: ‘Microstructures and wear property of friction stir welded AZ91Mg/SiC particle reinforced composite’, Compos. Sci. Technol., 2006, 66, 1513–1520. doi: 10.1016/j.compscitech.2005.11.023
12.
FuR. D., SunZ. Q., SunR. C., LiY., LiuH. J. and LiuL.: ‘Improvement of weld temperature distribution and mechanical properties of 7050 aluminum alloy butt joints by submerged friction stir welding’, Mater. Des., 2011, 32, 4825–4831. doi: 10.1016/j.matdes.2011.06.039
13.
ZhangH. J., LiuH. J. and YuL.: ‘Microstructure and mechanical properties as a function of rotation speed in underwater friction stir welded aluminum alloy joints’, Mater. Des., 2011, 32, 4402–4407. doi: 10.1016/j.matdes.2011.03.073
14.
JieL. H., JieZ. H., XianH. Y. and LeiY.: ‘Mechanical properties of underwater friction stir welded 2219 aluminum alloy’, Trans. Nonferr. Met. Soc. China, 2010, 20, 1387–1391. doi: 10.1016/S1003-6326(09)60309-5
15.
LiuH., FengX. and LippoldJ. C.: ‘Microstructure characterization of the stir zone of submerged friction stir processed aluminum alloy 2219’, Mater. Charact., 2013, 82, 97–102. doi: 10.1016/j.matchar.2013.05.010
16.
NiD. R., ChenD. L., YangJ. and MaZ. Y.: ‘Low cycle fatigue properties of friction stir welded joints of a semi-solid processed AZ91D magnesium alloy’, Mater. Des., 2014, 56, 1–8. doi: 10.1016/j.matdes.2013.10.081
17.
ChaiF., ZhangD., LiY. and ZhangW.: ‘High strain rate superplasticity of a fine-grained AZ91 magnesium alloy prepared by submerged friction stir processing’, Mater. Sci. Eng. A, 2013, A568, 40–48. doi: 10.1016/j.msea.2013.01.026
18.
HosseiniV. A., AashuriH. and KokabiA. H.: ‘Characterization of newly developed semisolid stir welding method for AZ91 magnesium alloy by using Mg–25%Zn interlayer’, Mater. Sci. Eng. A, 2013, A565, 165–171. doi: 10.1016/j.msea.2012.12.034
19.
DarrasB., OmarM. and KhraishehM.: ‘Experimental thermal analysis of friction stir processing’, Mater. Sci. Forum, 2007, 539, 3801–3806. doi: 10.4028/www.scientific.net/MSF.539-543.3801
20.
ZhangH. J., LiuH. J. and YuL.: ‘Microstructural evolution and its effect on mechanical performance of joint in underwater friction stir welded 2219-T6 aluminium alloy’, Sci. Technol. Weld. Join., 2011, 16, (5), 459–464. doi: 10.1179/1362171811Y.0000000024
21.
DarrasB. and KishtaE.: ‘Submerged friction stir processing of AZ31 Magnesium alloy’, Mater. Des., 2013, 47, 133–137. doi: 10.1016/j.matdes.2012.12.026
22.
KhayyaminD., MostafapourA. and KeshmiriR.: ‘The effect of process parameters on microstructural characteristics of AZ91/SiO2 composite fabricated by FSP’, Mater. Sci. Eng. A, 2013, A559, 217–221. doi: 10.1016/j.msea.2012.08.084
23.
AsadiaP., MahdavinejadaR. A. and TutunchilarS.: ‘Simulation and experimental investigation of FSP of AZ91 magnesium alloy’, Mater. Sci. Eng. A, 2011, A528, 6469–6477. doi: 10.1016/j.msea.2011.05.035
24.
González-MartínezR., GökenJ., LetzigD., SteinhoffK. and KainerK. U.: ‘Influence of aging on damping of the magnesium–aluminium–zinc series’, J. Alloys Compd, 2007, 437, 127–132. doi: 10.1016/j.jallcom.2006.07.085
25.
AhmadkhanihaD., Heydarzadeh SohiM. and Zarei-HanzakiA.: ‘Optimisation of friction stir processing parameters to produce sound and fine grain layers in pure magnesium’, Sci. Technol. Weld. Join., 2014, 19, (3), 235–241. doi: 10.1179/1362171813Y.0000000186
26.
ZhangD., WangS., QiuC. and ZhangW.: ‘Superplastic tensile behavior of a fine-grained AZ91 magnesium alloy prepared by friction stir processing’, Mater. Sci. Eng. A, 2012, A556, 100–106. doi: 10.1016/j.msea.2012.06.063
27.
FarrokhiH., HeidarzadehA. and SaeidT.: ‘Frictions stir welding of copper under different welding parameters and media’, Sci. Technol. Weld. Join., 2013, 18, 697–702. doi: 10.1179/1362171813Y.0000000148
28.
XuW. F., LiuJ. H., ChenD. L., LuanG. H. and YaodJ. S.: ‘Improvements of strength and ductility in aluminum alloy joints via rapid cooling during friction stir welding’, Mater. Sci. Eng. A, 2012, A548, 89–98. doi: 10.1016/j.msea.2012.03.094
29.
ForstH. J. and AshbyM. F.: ‘Deformation-mechanism maps’, 21–44; 1982, Oxford, Pergamon Press.
30.
YazdipourA., ShafieiA. and DehghaniM. K.: ‘Modeling the microstructural evolution and effect of cooling rate on the nanograins formed during the friction stir processing of Al5083’, Mater. Sci. Eng. A, 2009, A527, 192–197. doi: 10.1016/j.msea.2009.08.040
31.
‘ASM International metals handbook’, 10th edn, Vol. 2, 455; 1990, Metals Park, OH, ASM International.
