Synergistic effect of Y and Ca addition on the texture modification in AZ31B magnesium alloy
Synergistic effect of Y and Ca addition on the texture modification in AZ31B magnesium alloy
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DOI：
10.1016/j.actamat.2022.117990
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发表时间：
2022-05-07
期刊：
影响因子：
9.4
通讯作者：
Al-Samman, Talal
中科院分区：
文献类型：
--
作者：
Pei, Risheng;Zou, Yongchun;Al-Samman, Talal
调整析出量和溶质偏析是现代微合金化镁合金中采用的一种成功的策略，以调整组织和织构以提高强度和成形性。本文通过在AZ31B合金中添加Ca和/或Y来研究各种合金元素在再结晶和晶粒长大过程中对织构和组织演变的协同作用。这项工作研究了合金元素在不同基体成分和不同晶界的偏析行为，旨在深入了解导致织构变质的有利生长机制。结果表明，在AZW合金(Mg-3Al1Zn-1.0Y wt.%)中，由于Al和Mn的析出，在基体中没有Y溶质。因此，该合金的织构与典型的镁基织构非常相似。在AZWX合金(Mg-3Al-1Zn-0.3Ca-1.0Y wt.%)中加入Ca和Y后，由于Y取代了Ca，形成了稳定的Al2Y析出物，因此，基体中的Ca溶质含量仍然足够大。这导致了在固溶体中钙的有效性及其在晶界与铝、锌共偏析的基础上的强烈织构变质。因此，AZWX合金的再结晶动力学受到溶质和析出相关效应的显著抑制。相应地，由于晶界没有溶质阻力，AZW合金表现出最快的再结晶动力学。含Ca但不含Y的AZX(Mg-3Al-1Zn-0.3Ca)合金介于两者之间，表现出晶界偏析，但小于AZWX合金的晶界偏析。认为在碱性镁铝锌合金中加入Ca和Y可以放大溶质元素在触发晶界各向异性偏析中的协同作用。这在改变生长过程中的晶界迁移率特征方面似乎很重要，这使得非基晶具有生长优势，导致了退火织构的修改。这项工作揭示了一种成功的镁合金战略，通过定制沉淀和各向异性偏析的类型和水平，以实现所需的织构修改。(C)2022材料学报公司。由爱思唯尔有限公司出版。保留所有权利。
Tweaking the amount of precipitation and solute segregation is a successful strategy employed in modern micro-alloyed Mg alloys to tailor the microstructure and texture towards improved strength and formability. In the current work, Ca and / or Y are added to AZ31B alloy to examine the synergistic effect of various alloying elements on the texture and microstructure evolution during recrystallization and grain growth. The work examines the segregation behavior of alloying elements with respect to different matrix compositions and different grain boundaries and aims at gaining insights into favorable growth mechanisms that lead to texture modifications. The results demonstrate that in the AZW alloy (Mg-3Al1Zn-1.0Y wt.%) no Y solute was available in the matrix due to precipitation with Al and Mn. Hence, the texture of this alloy was very similar to typical magnesium basal textures. By the co-addition of Ca and Y in the AZWX alloy (Mg-3Al-1Zn-0.3Ca-1.0Y wt.%), the amount of Ca solute in the matrix remained large enough because Y replaced Ca in forming stable Al2Y precipitates. This resulted in a strong texture modification on the basis of Ca availability in solid solution and its co-segregation with Al and Zn at grain boundaries. The recrystallization kinetics in the AZWX alloy was therefore markedly retarded due to solute and precipitation related effects. Correspondingly, the AZW alloy showed the fastest recrystallization kinetics due to the lack of solute drag at the grain boundaries. The third alloy, AZX (Mg-3Al-1Zn-0.3Ca) containing Ca but no Y was in between because it demonstrated grain boundary segregation but less than the counterpart in the AZWX alloy. It is believed that the co-addition of Ca and Y to the basic MgAl-Zn alloy magnifies the synergistic role of solute elements in triggering anisotropic segregation among grain boundaries. This seems significant in modifying the grain boundary mobility characteristics during growth, which grants non-basal grains a growth advantage, resulting in annealing texture modification. This work sheds light on a successful magnesium alloying strategy by tailoring the type and level of precipitation and anisotropic segregation to achieve a desired texture modification.(c) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.