Magnesium rare earth alloys have been received extensive attention due to their attractive mechanical properties. The precipitation sequence in laser welded Mg–3Nd–0·2Zn–0·4Zr (NZ30K) alloy during aging treatment has been investigated using transmission electron microscopy (TEM). The results show that the tensile strength of laser welded NZ30K can be improved significantly after aging treatment at 200°C for 8 h. The precipitation in laser welded NZ30K alloy follows the sequence of super saturated solid solution→β″(DO19)→β′(fcc)→β. The results of incremental of critical shear stress component are Δτs/Δτp/Δτr/Δτf = 1·86∶3·57∶3·14∶1. The platelet of precipitates with high volume fraction is the most important factor that enhances aging treatment strengthening.
LiMZ, WangYQ, LiC, LiuXG, XuBS: ‘Effects of neodymium rich rare earth elements on microstructure and mechanical properties of as cast AZ31 magnesium alloy’, Mater. Sci. Technol., 2011, 27, 1138–1142.
5.
YoonEY, LeeDJ, KimTS, ChaeHJ, JeneiP, GubiczaJ, KimHS: ‘Microstructures and mechanical properties of Mg–Zn–Y alloy consolidated from gas-atomized powders using high-pressure torsion’, J. Mater. Sci., 2012, 47, 7117–7123.
6.
JianWW, KangZX, LiYY: ‘Effect of hot plastic deformation on microstructure and mechanical property of Mg-Mn-Ce magnesium alloy’, Trans. Nonfer. Metal. Soc. China, 2007, 17, 1158–1163.
7.
ChengRJ, PanFS, JiangS, JiangXQ, LiC: ‘Effect of minor Sr on precipitates in AZ31 magnesium alloys’, Mater. Sci. Technol., 2013, 29, 219–225.
8.
YangMB, PanFS, ShenJ, MaYL: ‘Effects of minor additions of Ce and Y on as cast microstructure of Mg-3Sn-2Ca magnesium alloy’, Mater. Sci. Technol., 2012, 28, 509–512.
9.
ChangJW, PengLM, GuoXW, AtrensA, FuPH, DingWJ, WangXS: ‘Comparison of the corrosion behaviour in 5 NaCl solution of Mg alloys NZ30K and AZ91D’, J. Appl. Electrochem., 2008, 38, 207–214.
10.
FuPH, PengLM, JiangHY, ChangJW, ZhaiCQ: ‘Effects of heat treatments on the microstructures and mechanical properties of Mg–3Nd–0·2Zn–0·4Zr (wt.) alloy’, Mater. Sci. Eng. A, 2008, A486, 183–192.
11.
ChangJW, GuoXW, FuPH, PengLM, DingWJ: ‘Effect of heat treatment on corrosion and electrochemical behaviour of Mg–3Nd–0·2 Zn–0·4 Zr (wt.) alloy’, Electrochim. Acta, 2007, 52, 3160–3167.
12.
ChangJW, FuPH, GuoXW, PengLM, DingWJ: ‘The effects of heat treatment and zirconium on the corrosion behaviour of Mg–3Nd–0·2Zn–0·4Zr (wt.) alloy’, Corros. Sci., 2007, 49, 2612–2627.
13.
BaruccaG, FerragutR, FioriF, LussanaD, MengucciP, MoiaF, RiontinoG: ‘Formation and evolution of the hardening precipitates in a Mg–Y–Nd alloy’, Acta Mater., 2011, 59, 4151–4158.
NieJF, XiaoXL, LuoCP, MuddleBC: ‘Characterisation of precipitate phases in magnesium alloys using electron microdiffraction’, Micron., 2001, 32, 857–863.
SmolaB, StulıkováI, BuchFV, MordikeBL: ‘Structural aspects of high performance Mg alloys design’, Mater. Sci. Eng. A, 2002, A324, 113–117.
18.
AtiyaG, BambergerM, KatsmanA: ‘Microstructure, phase evolution and precipitation strengthening of Mg-3. lNd-0·45 Zr-0·25 Zn Alloy’, Magnes. Technol., 2011, 249–253.
19.
VillarsP, CalvertLD: ‘Pearson's handbook of crystallographic data for intermetallic phases’,Metals Park, OH, American Society for Metals, 1985, 3, 2710.
20.
HeSM, ZengXQ, PengLM, GaoX, NieJF, DingWJ: ‘Precipitation in a Mg–10Gd–3Y–0·4 Zr (wt.) alloy during isothermal ageing at 250°C’, J. Alloy. Compd, 2006, 421, 309–313.
21.
AntionC, DonnadieuP, PerrardF, DeschampsA, TassinC, PischA: ‘Hardening precipitation in a Mg–4Y–3RE alloy’, Acta Mater., 2003, 51, 5335–5348.
22.
HeSM: ‘Study on the microstructural evolution, properties and fracture behavior of Mg-Gd-Y-Zr(-Ca) alloys’, PhD thesis, Shanghai Jiao Tong University, Shanghai, China, 2007, 219–222.
23.
NieJF: ‘Effects of precipitate shape and orientation on dispersion strengthening in magnesium alloys’, Scr. Mater., 2003, 48, 1009–1015.
