Effect of yttrium content on the ultra-high cycle fatigue behavior of Mg-Zn-Y-Zr alloys
In the super-long life regime,the fatigue behavior of as-extruded Mg-6wt%Zn-xY-0.8wt%Zr Mg alloys with Y content of 0,1,2 and 3 wt% have been investigated,respectively.The result indicates that for all measured S-N curves,a plateau exists in the regime of 5×106-108 cyc,and then the fatigue strength gradually decreases between 108 and 109 cyc.Therefore,only fatigue strength corresponding to 109 cyc can be determined.Compared with other alloys,the alloy with Y content of 2 wt% has the highest fatigue strength and its value is 105 MPa.SEM observations to fracture surfaces reveal that for all alloys,the fatigue crack mostly initiates at the surface or subsurface of samples failed within 106-109 cyc.Further observation indicates that the crack initiation is related with activated slip bands instead of phase particles and activated twins.Based on the measured results and Murakami equation,it demonstrates that the fatigue strength of alloys is more dependent on the hardness values.
Mg alloy super-long fatigue slip band fatigue properties
D.K.Xu E.H.Han
State Key Laboratory for Corrosion and Protection,Institute of Metal Research,Chinese Academy of Sciences,62 Wencui Road,Shenyang 110016,China
国际会议
北京
英文
1-7
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）