The present investigation deals with the microstructural modification following the Bi + Sr additions to the squeeze-cast AZ91 alloy and its effect on impression creep response. The Bi + Sr additions form the Al4Sr and Sr2Bi phases besides the α-Mg and β-Mg17Al12 phases, and improves creep resistance of the AZ91 alloy. The AZ91 + 1.0Bi + 0.5Sr alloy reveals the best creep resistance among the alloys. The stress exponent and the activation energy values of all the alloys are in the range of 4–7 and 100.2–112.7 kJ mol−1, respectively, depicting the pipe diffusion-controlled dislocation creep is the governing creep mechanism. The post-creep microstructural study confirms several dislocations pile-ups around the Al4Sr and Sr2Bi phases resulting in improved creep resistance of the modified AZ91 alloys.
KulekciMK.Magnesium and its alloys applications in automotive industry. Int J Adv Manuf Technol. 2008; 39(9–10):851–865. doi: 10.1007/s00170-007-1279-2
2.
LuoAA.Recent magnesium alloy development for elevated temperature applications. Int Mater Rev. 2004; 49(1):13–30. doi: 10.1179/095066004225010497
3.
KabirianFMahmudiR.Impression creep behavior of a cast AZ91 magnesium alloy. Metall Mater Trans A. 2009; 40(1):116–127. doi: 10.1007/s11661-008-9699-7
4.
SrinivasanASwaminathanJGunjanMKEffect of intermetallic phases on the creep behavior of AZ91 magnesium alloy. Mater Sci Eng A. 2010; 527(6):1395–1403. doi: 10.1016/j.msea.2009.10.008
5.
PanFYangMChenX.A review on casting magnesium alloys: modification of commercial alloys and development of new alloys. J Mater Sci Technol. 2016; 32(12):1211–1221. doi: 10.1016/j.jmst.2016.07.001
6.
MoNTanQBerminghamMCurrent development of creep-resistant magnesium alloys: a review. Mater Des. 2018; 155:422–442. doi: 10.1016/j.matdes.2018.06.032
7.
ZhangDZhangDBuFEffects of minor Sr addition on the microstructure, mechanical properties and creep behavior of high pressure die cast AZ91-0.5RE based alloy. Mater Sci Eng A. 2017; 693:51–59. doi: 10.1016/j.msea.2017.03.055
8.
DarguschMSZhuSMNieJFMicrostructural analysis of the improved creep resistance of a die-cast magnesium–aluminium–rare earth alloy by strontium additions. Scr Mater. 2009; 60:116–119. doi: 10.1016/j.scriptamat.2008.09.013
9.
YangFLiJC.Impression test – a review. Mater Sci Eng R. 2013; 74(8):233–253. doi: 10.1016/j.mser.2013.06.002
10.
GeranmayehARMahmudiR.Compressive and impression creep behavior of a cast Mg-Al-Zn-Si alloy. Mater Chem Phys. 2013; 139(1):79–86. doi: 10.1016/j.matchemphys.2012.12.040
11.
AnsarySMahmudiREsfandyarpourMJ.Creep of AZ31 Mg alloy: a comparison of impression and tensile behavior. Mater Sci Eng A. 2012; 556:9–14. doi: 10.1016/j.msea.2012.06.052
12.
MahmudiRMoeendarbariS.Effects of tin additions on the microstructure and impression creep behavior of AZ91 magnesium alloy. Mater Sci Eng A. 2013; 566:30–39. doi: 10.1016/j.msea.2012.12.076
13.
KeyvaniMMahmudiRNayyeriG.Microstructure and impression creep characteristics of cast Mg-5Sn-xBi magnesium alloys. Metall Mater Trans A. 2011; 42(7):1990–2003. doi: 10.1007/s11661-010-0564-0
14.
GhomashchiMRVikhrovA.Squeeze casting: an overview. J Mater Process Technol. 2000; 101(1–3):1–9. doi: 10.1016/S0924-0136(99)00291-5
MasoumiMHuH.Influence of applied pressure on microstructure and tensile properties of squeeze cast magnesium Mg-Al-Ca alloy. Mater Sci Eng A. 2011; 528(10–11):3589–3593. doi: 10.1016/j.msea.2011.01.032
17.
GohCSSohKSOonPHEffect of squeeze casting parameters on the mechanical properties of AZ91-Ca Mg alloys. Mater Des. 2010; 31:S50–S53. doi: 10.1016/j.matdes.2009.11.039
18.
ZhuSMMordikeBLNieJF.Creep properties of a Mg–Al–Ca alloy produced by different casting technologies. Mater Sci Eng A. 2008; 483–484:583–586. doi: 10.1016/j.msea.2006.09.154
19.
BankotiAKMondalAKDieringaHImpression creep behaviour of squeeze-cast Ca and Sb added AZ91 magnesium alloy. Mater Sci Eng A. 2016; 673:332–345. doi: 10.1016/j.msea.2016.07.087
20.
BankotiAKMondalAKKumarSIndividual and combined additions of calcium and antimony on microstructure and mechanical properties of squeeze-cast AZ91D magnesium alloy. Mater Sci Eng A. 2015; 626:186–194. doi: 10.1016/j.msea.2014.12.068
21.
LiuHBGongNPangLMicrostructure and mechanical properties of as cast AZ31 with the addition of Sb. Mater Sci Eng A. 2008; 497:254–259. doi: 10.1016/j.msea.2008.07.010
22.
GuangyinYYangshanSWenjiangD.Effects of bismuth and antimony additions on the microstructure and mechanical properties of AZ91 magnesium alloy. Mater Sci Eng A. 2001; 308:38–44. doi: 10.1016/S0921-5093(00)02043-8
23.
IshikawaKWatanabeHMukaiT.High strain rate deformation behavior of an AZ91 magnesium alloy at elevated temperatures. Mater Lett. 2005; 59(12):1511–1515. doi: 10.1016/j.matlet.2005.01.012
24.
BlumWZhangPWatzingerBComparative study of creep of the die-cast Mg-alloys AZ91, AS21, AS41, AM60, and AE42. Mater Sci Eng A. 2001; 319–321:735–740. doi: 10.1016/S0921-5093(00)02016-5
25.
MukherjeeABirdJEDornJE.Experimental correlations for high temperature creep. Trans ASM. 1969; 62:155–179.
26.
SomekawaHHiraiKWatanabeHDislocation creep behavior in Mg-Al-Zn alloys. Mater Sci Eng A. 2005; 407(1–2):53–61. doi: 10.1016/j.msea.2005.06.059
27.
RobinsonSLSherbyOD.Mechanical behavior of polycrystalline tungsten at elevated temperature. Acta Metall. 1969; 17(2):109–125. doi: 10.1016/0001-6160(69)90132-1
28.
NamiBRazaviHMirdamadiSEffect of Ca and rare earth elements on impression creep properties of AZ91 magnesium alloy. Metall Mater Trans A. 2010; 41(8):1973–1982. doi: 10.1007/s11661-010-0238-y
29.
KabirianFMahmudiR.Effects of Zr additions on the microstructure and impression creep behavior of AZ91 magnesium alloy. Metall Mater Trans A. 2010; 41(13):3488–3498. doi: 10.1007/s11661-010-0398-9
30.
KimWJChungSWChungCSSuperplasticity in thin magnesium alloy sheets and deformation mechanism maps for magnesium alloys at elevated temperatures. Acta Mater. 2001; 49(16):3337–3345. doi: 10.1016/S1359-6454(01)00008-8
31.
SpingarnJRBarnettDMNixWD.Theoretical descriptions of climb controlled steady state creep at high and intermediate temperatures. Acta Metall. 1979; 27(9):1549–1561. doi: 10.1016/0001-6160(79)90177-9
32.
GangulySMondalAK.Influence of SiC nanoparticles addition on microstructure and creep behavior of squeeze-cast AZ91-Ca-Sb magnesium alloy. Mater Sci Eng A. 2018; 718:377–389. doi: 10.1016/j.msea.2018.01.131
33.
WangREliezerAGutmanE.An investigation on the microstructure of an AM50 magnesium alloy. Mater Sci Eng A. 2003; 355(1–2):201–207. doi: 10.1016/S0921-5093(03)00065-0
34.
WangREliezerAGutmanE.Microstructures and dislocations in the stressed AZ91D magnesium alloys. Mater Sci Eng A. 2003; 344(1–2):279–287. doi: 10.1016/S0921-5093(02)00413-6
35.
SunYYanJXueFCreep behavior of Mg–2wt.%Nd binary alloy. Mater Sci Eng A. 2009; 524(1–2):102–107. doi: 10.1016/j.msea.2009.06.008
36.
TeradaYItohDSatoT.Dislocation analysis of die-cast Mg – Al – Ca alloy after creep deformation. Mater Sci Eng A. 2009; 523(1–2):214–219. doi: 10.1016/j.msea.2009.07.001
37.
TerBushJRSuzukiASaddockNDDislocation substructures of three die-cast Mg-Al-Ca-based alloys. Scr Mater. 2008; 58(10):914–917. doi: 10.1016/j.scriptamat.2008.01.015
