The stress corrosion cracking behavior of friction stir processed, micro arc oxidation coated and a composite coated (friction stir processed-micro arc oxidation) ZE41 magnesium alloy were studied in modified simulated body fluid (m-SBF) solution at room temperature. Friction stir processing was carried out with a tool rotation speed of 650 rpm and a traverse speed of 50 mm/min. The results showed that fine equi-axed grain structure with an average grain size of ∼2.8 µm, fragmentation, and partial dissolution of T-phase and Zr-rich particles was achieved through friction stir processing. Specially designed two electrode coating method was adopted to produce samples with micro arc oxidation coating in silicate solution. The stress corrosion cracking susceptibility of base metal, friction stir processed, micro arc oxidation, and composite coated friction stir processed-micro arc oxidation samples were evaluated through constant load testing at five different stress levels. The results indicated higher stress corrosion cracking susceptibility for base metal compared to friction stir processed; micro arc oxidation and friction stir processed-micro arc oxidation samples. Grain refinement and microstructure homogenization enhanced stress corrosion cracking resistance of friction stir processed sample whereas the barrier effect of coating during initial stages of corrosion improved stress corrosion cracking resistance of micro arc oxidation sample compared to base metal. Among all the samples, friction stir processed-micro arc oxidation exhibited superior stress corrosion cracking resistance due to the self-repairing mechanism of friction stir processing, which in turn improved the corrosion resistance of micro arc oxidation layer. The fractographic features revealed different stress corrosion cracking mechanisms for base metal, friction stir processed, micro arc oxidation, and friction stir processed-micro arc oxidation samples. T-phase and Zr-rich particles played major role in the initiation of corrosion pits and resulted in stress corrosion cracks.
MaoLZhouHChenL, et al.Enhanced biocompatibility and long-term durability in vivo of Mg-Nd-Zn-Zr alloy for vascular stent application. J Alloys Compd2017; 720: 245–253.
2.
Cesarz-AndraczkeKNowosielskiRBabilasR. Corrosion properties of Mg-Zn-Ca-(Cu,Au) metallic glasses in artificial physiological fluid. Arch Civ Mech Eng2019; 19: 716–723.
3.
LeszSKraczlaJNowosielskiR. Structure and compression strength characteristics of the sintered Mg–Zn–Ca–Gd alloy for medical applications. Arch Civ Mech Eng2018; 18: 1288–1299.
4.
StaigerMPPietakAMHuadmaiJ, et al.Magnesium and its alloys as orthopedic biomaterials: a review. Biomaterials2006; 27: 1728–1734.
5.
WinzerNAtrensASongG, et al.A critical review of the stress corrosion cracking (SCC) of magnesium alloys. Adv Eng Mater2005; 7: 659–693.
6.
KannanMBDietzelWBlawertC, et al.Stress corrosion cracking of rare-earth containing magnesium alloys ZE41, QE22 and Elektron 21 (EV31A) compared with AZ80. Mater Sci Eng A2008; 480: 529–539.
7.
KannanMBRamanRKS. In vitro degradation and mechanical integrity of calcium-containing magnesium alloys in modified-simulated body fluid. Biomaterials2008; 29: 2306–2314.
8.
KannanMBRamanRKS. Evaluating the stress corrosion cracking susceptibility of Mg–Al–Zn alloy in modified-simulated body fluid for orthopaedic implant application. Scr Mater2008; 59: 175–178.
9.
JiangJMaASaitoN, et al.Improving corrosion resistance of RE-containing magnesium alloy ZE41A through ECAP. J Rare Earths2009; 27: 848–852.
10.
ArgadeGRKandasamyKPanigrahiSK, et al.Corrosion behavior of a friction stir processed rare-earth added magnesium alloy. Corros Sci2010; 58: 321–326.
11.
AroraHSSinghHDhindawBK. Corrosion behavior of a Mg Alloy AE42 subjected to friction stir processing. Corrosion2013; 69: 122–135.
12.
MiyamotoH. Corrosion of ultrafine grained materials by severe plastic deformation, an overview. Mater Trans2016; 57: 559–572.
13.
XiongFFuRLiYJ, et al.Effects of nitrogen alloying and friction stir processing on the microstructures and mechanical properties of CoCrFeMnNi high-entropy alloys. J Alloys Compd2019; 822: 153512–153512.
14.
WangWHanPPengP, et al.Friction stir processing of magnesium alloys: a review. Acta Metall Sin2020; 33: 43–57.
15.
JinYWangKWangW, et al.Microstructure and mechanical properties of AE42 rare earth-containing magnesium alloy prepared by friction stir processing. Mater Charact2019; 150: 52–61.
16.
VargasMLathabaiSUggowitzerPJ, et al.Microstructure, crystallographic texture and mechanical behaviour of friction stir processed Mg-Zn-Ca-Zr alloy ZKX50. Mater Sci Eng A2017; 685: 253–264.
17.
XiaoBLYangQYangJ, et al.Enhanced mechanical properties of Mg–Gd–Y–Zr casting via friction stir processing. J Alloys Compd2011; 509: 2879–2884.
18.
ArgadeGRYuanWKandasamyK, et al.Stress corrosion cracking susceptibility of ultrafine grained AZ31. J Mater Sci2011; 47: 6812–6822.
19.
HuangLWangKWenW, et al.Effects of grain size and texture on stress corrosion cracking of friction stir processed AZ80 magnesium alloy. Eng Fail Anal2018; 92: 392–404.
20.
MuhaffelFMertFCimenogluH, et al.Characterisation and corrosion behaviour of plasma electrolytic oxidation coatings on high pressure die cast Mg–5Al–0.4Mn–xCe (x = 0, 0.5, 1) alloys. Surf Coat Technol2015; 269: 200–211.
21.
JiangBLGeYF. Micro-arc oxidation (MAO) to improve the corrosion resistance of magnesium (Mg) alloys. Corros Prev Magnes Alloys2013, pp. 163–196.
22.
SrinivasanBPBlawertCDietzelW. Effect of plasma electrolytic oxidation treatment on the corrosion and stress corrosion cracking behaviour of AM50 magnesium alloy. Mater Sci Eng A2008; 494: 401–406.
23.
Bala SrinivasanPLiangJBlawertC, et al.Environmentally assisted cracking behaviour of plasma electrolytic oxidation coated AZ31 magnesium alloy. Corros Eng Sci Technol2011; 46: 706–711.
24.
KogantiRLakshminarayananAKRamprabhuT. Advances in materials and metallurgy, Berlin: Springer, 2019, pp. 427–435.
25.
Kamal JayarajRMalarvizhiSBalasubramanianV. Optimizing the micro-arc oxidation (MAO) parameters to attain coatings with minimum porosity and maximum hardness on the friction stir welded AA6061 aluminium alloy welds. Def Techn2017; 13: 111–117.
26.
OyaneAKimHMFuruyaT, et al.Preparation and assessment of revised simulated body fluids. J Biomed Mater Res2003; 65: 188–195.
27.
XinRZhengXLiuZ, et al.Microstructure and texture evolution of an Mg–Gd–Y–Nd–Zr alloy during friction stir processing. J Alloys Compd2016; 659: 51–59.
28.
HuangYWangYMengX, et al.Dynamic recrystallization and mechanical properties of friction stir processed Mg-Zn-Y-Zr alloys. J Mater Process Tech2017; 249: 331–338.
29.
MahmoudTS. Effect of friction stir processing on electrical conductivity and corrosion resistance of AA6063-T6 Al alloy. Proc IMechE Part C: J Mechanical Engineering Science2008; 222: 1117–1123.
30.
CoyAEViejoFSkeldonP, et al.Susceptibility of rare-earth-magnesium alloys to micro-galvanic corrosion. Corros Sci2010; 52: 3896–3906.
NeilWCForsythM. Corrosion of magnesium alloy ZE41 – the role of microstructural features. Corros Sci2009; 51: 387–394.
33.
ArbegastWJHartleyPJ. In: Proceedings of the Fifth International Conference on Trends in Welding Research, Pine Mountain, GA, USA, 1–5 June 1998, pp. 541–546.
34.
ComminLDumontMMasseJE, et al.Friction stir welding of AZ31 magnesium alloy rolled sheets: influence of processing parameters. Acta Mater2009; 57: 326–334.
35.
NeilWCForsythMHowlettPC, et al.Corrosion of heat treated magnesium alloy ZE41. Corros Sci2011; 53: 3299–3308.
36.
Barooghi B, Sheikhi M and Amiri A. Effect of nanohydroxyapatite and dutycycle on the structure and corrosion performance of plasma electrolyte oxidation coatings in simulated body fluid on Ti6Al4 V. Proc IMechE Part C: J Mechanical Engineering Science 2018; 232: 4229–4236.
37.
Bala SrinivasanPLiangJBlawertC, et al.Effect of current density on the microstructure and corrosion behaviour of plasma electrolytic oxidation treated AM50 magnesium alloy. Appl Surf Sci2009; 255: 4212–4218.
38.
PadekarBSSingh RamanRK, et al.Stress corrosion cracking of a recent rare-earth containing magnesium alloy, EV31A, and a common Al-containing alloy, AZ91E. Corros Sci2013; 71: 1–9.
39.
NishimuraRKudoK. Stress corrosion cracking of AISI 304 and AISI 316 austenitic stainless steels in HCl and H2SO4 solutions prediction of time-to-failure and criterion for assessment of SCC susceptibility. J Corros1989; 45: 308–316.
40.
LiJPWangPGuoYC, et al.Microstructure and microgalvanic corrosion of an extruded Mg-10Gd-2Y-0.5Zr magnesium Alloy. Mater Sci Forum2013; 765: 683–687.
41.
BradyMPFayekMElsentriecyHH, et al.Tracer film growth study of hydrogen and oxygen from the corrosion of magnesium in water. J Electrochem Soc2014; 161: C395–C404.
42.
MostaedEHashempourMFabriziA, et al.Microstructure, texture evolution, mechanical properties and corrosion behavior of ECAP processed ZK60 magnesium alloy for biodegradable applications. J Mech Behav Biomed2014; 37: 307–322.
43.
RuggeriRTBeckTR. An analysis of mass transfer in filiform corrosion. Corrosion1983; 39: 452–465.
44.
SongDMaABJiangJH, et al.Corrosion behaviour of bulk ultra-fine grained AZ91D magnesium alloy fabricated by equal-channel angular pressing. Corros Sci2011; 53: 362–373.
45.
SongWMartinHJHicksA, et al.Corrosion behaviour of extruded AM30 magnesium alloy under salt-spray and immersion environments. Corros Sci2014; 78: 353–368.
46.
Ben-HamuGEliezerDShinKS, et al.The relation between microstructure and corrosion behavior of Mg–Y–RE–Zr alloys. J Alloys Compd2007; 431: 269–276.
47.
YangJLuXBlawertC, et al.Microstructure and corrosion behavior of Ca/P coatings prepared on magnesium by plasma electrolytic oxidation. Surf Coat Technol2017; 319: 359–369.
48.
AfshariVDehghanianC. Effects of grain size on the electrochemical corrosion behavior of electrodeposited nanocrystalline Fe coatings in alkaline solution. Corros Sci2009; 51: 1844–1849.
49.
LiuLLiYWangF. Influence of grain size on the corrosion behavior of a Ni-based superalloy nanocrystalline coating in NaCl acidic solution. Electrochim Acta2008; 53: 2453–2462.
50.
RalstonKDBirbilisN. Effect of grain size on corrosion: a review. Corrosion2010; 66: 075005–075005–13.
51.
GaoLZhangCZhangM, et al.The corrosion of a novel Mg–11Li–3Al–0.5RE alloy in alkaline NaCl solution. J Alloys Compd2009; 468: 285–289.
