Comparison of high cycle fatigue behaviors of Mg–3Nd–0.2Zn–Zr alloy prepared by different casting processes
Comparison of high cycle fatigue behaviors of Mg–3Nd–0.2Zn–Zr alloy prepared by different casting processes
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DOI：
10.1016/j.msea.2013.05.040
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发表时间：
2013-09
期刊：
影响因子：
6.4
通讯作者：
Zhiqiang Li;P. Fu;L. Peng;Ying-xin Wang;Hong Jiang;Guohua Wu
中科院分区：
文献类型：
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作者：
Zhiqiang Li;P. Fu;L. Peng;Ying-xin Wang;Hong Jiang;Guohua Wu
采用无气孔低压砂型铸锭（LPS）和含少量气孔的重力永久型铸锭（GPM）研究了铸造缺陷对Mg-3Nd-0.2Zn-Zr镁合金疲劳行为的影响。结果表明，孔隙度对疲劳强度和寿命有不利影响。与滑移带和双带破坏试样相比，孔隙破坏试样的疲劳强度和寿命明显降低。疲劳强度随屈服强度的增大而增大。无孔隙度的t6处理试样的疲劳强度由基底滑移阈值应力决定，而基底滑移阈值应力与滑移带、析出相和晶界之间的相互作用有关。晶界约束和孪晶引起的不可逆循环变形是影响LPS处理无孔隙度t4试样疲劳强度的关键因素。
The influences of casting defects on the fatigue behaviors of Mg–3Nd–0.2Zn–Zr magnesium alloys were studied using porosity-free low pressure sand mold casting bars (LPS) and gravity permanent mold casting ingots (GPM) containing a few porosities. The results show that porosities have detrimental effect on the fatigue strength and life. The samples failed from the porosities show much lower fatigue strength and life in comparison with those failed from slip bands and twin bands. The fatigue strength increases with the yield strength increasing. Fatigue strength of the porosity-free T6-treated specimens made by LPS is determined by the threshold stress for basal slip, which is related to the interactions among slip bands, precipitates and grain boundaries. Both grain boundary constraints and cyclic deformation irreversibly caused by twinning are the crucial factors influencing the fatigue strengths of the porosity-free T4-treated specimens made by LPS.