Enhancing strength and creep resistance of Mg-Gd-Y-Zn-Zr alloy by substituting Mn for Zr
Enhancing strength and creep resistance of Mg-Gd-Y-Zn-Zr alloy by substituting Mn for Zr
复制标题
以Mn代替Zr提高Mg-Gd-Y-Zn-Zr合金的强度和抗蠕变性能
DOI：
10.1016/j.jma.2019.04.007
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发表时间：
2019-09-01
影响因子：
17.6
通讯作者：
Karnado, S.
中科院分区：
文献类型：
--
作者：
Xu, C.;Nakata, T.;Karnado, S.
研究了添加Zr或Mn的挤压态Mg-2Gd-1.2Y-0.5Zn合金的时效硬化行为和力学性能。结果表明，添加Mn的合金比添加Zr的合金具有更显著的时效硬化效应，这是由于Mn在时效过程中以β相、β‘相和长周期堆积有序(LPSO)相的分配导致第二相中(Gd+Y)浓度的降低，有利于时效过程中的析出。两种峰值时效合金都表现出双峰组织，包括细小的DRXed晶粒和粗大的具有强烈纤维织构的加工晶粒。峰时效锰和添加锆合金均获得了较高的强度和良好的热稳定性。而峰时效加锰合金由于β‘相致密，LPSO相和伽马’相较薄，以及较高的加工晶粒面积分数和较强的纤维织构，具有较高的强度和优良的蠕变抗力。峰时效加锰合金的0.2%抗拉强度和极限抗拉强度分别达到454和508 Mpa，室温伸长率为3.2%。在250℃/150 MPa条件下，峰值时效加锰合金的最小蠕变速率为2.4×10~(-8)S(~(-1))，优于已有报道的挤压态Mg-Gd基合金。(C)2019年，爱思唯尔公司代表重庆大学出版。
The age-hardening behavior and mechanical properties of the extruded Mg-2Gd-1.2Y-0.5Zn (at.%) alloy with Zr or Mn additions were investigated. The results show that Mn added alloy exhibits more remarkable age-hardening response than Zr added alloy, which is attributed to the fact that partitioning of Mn into the beta phases, beta' precipitates and long period stacking ordered (LPSO) phases leads to the decrement in (Gd+Y) concentrations in the second phases, facilitating the precipitation during aging treatment. Both peak-aged alloys show bimodal microstructure comprising the fine DRXed grains with nano-sized beta phases pinned at DRXed grain boundaries as well as coarse worked grains with strong fiber texture. High strength and good thermal stability were obtained in both peak-aged Mn and Zr added alloys. While the peak-aged Mn added alloy shows higher strength and superior creep resistance due to its denser beta' precipitates, thin LPSO phases and gamma' precipitates and higher area fraction of worked grains with strong fiber texture. The 0.2% tensile proof stress and ultimate tensile strength of peak-aged Mn added alloy reach up to 454MPa and 508MPa, respectively, with elongation of 3.2% at room temperature. The minimum creep rate of the peak-aged Mn added alloy at 250 degrees C / 150MPa is 2.4 x 10(-8) s(-1), which is superior than previously reported extruded Mg-Gd based alloys. (C) 2019 Published by Elsevier B.V. on behalf of Chongqing University.