AZ91镁合金模拟累积叠轧过程中组织演化行为
Microstructure Evolution of AZ91 Magnesium Alloy During Simulated Accumulative Roll Bonding
肖心萍1, 于彦龙2, 李晓丹1
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作者单位：(1. 秦皇岛职业技术学院, 河北 秦皇岛 066100; 2. 大庆石油学院, 河北 秦皇岛 066004)
中文关键字：晶粒细化； 镁合金； 累积叠轧焊； 动态再结晶； 模拟
英文关键字：grain refinement; magnesium alloy; accumulative roll bonding (ARB); dynamic recrystallization; simulation
中文摘要：采用Gleeble-3500热/力动态模拟试验机研究了AZ91镁合金在变形温度为250～400 ℃、应变速率为10-3～1 s-1 条件下的热压缩变形行为。 并在此基础上，采用Gleeble-3500模拟累积叠轧焊轧制方法，对其在累积叠轧焊(ARB)过程中的组织演变和晶粒细化的机制进行了研究。结果表明： AZ91镁合金在热压缩变形过程中，适宜的变形工艺为变形温度350～400 ℃、应变速率10-3 ～10-2 s-1。 AZ91镁合金在变形温度350 ℃、应变速率0.01 s-1和变形量80%为工艺条件的累积叠轧焊过程中，晶粒在第一次轧制过程中明显细化，其机制发生了动态再结晶，在随后的叠轧过程中，晶粒细化程度有限，但组织均匀程度增加。
英文摘要：The hot compressive behavior of AZ91 magnesium alloy was studied at 250 ℃～400 ℃ and the strain rate of 10-3 s-1～10-2 s-1. The microstructure evolution and grain refinement mechanism in AZ91 magnesium alloy caused by three-run ARB was also examined using Gleeble-3500 simulator and transmission electron microscope (TEM). The results show that a sample without cracking can be obtained only at 350 ℃～400 ℃ and strain rate of 10-3 s-1～10-2 s-1 during hot deformation of the experimental AZ91 magnesium alloy. It is also discovered that, during the three-run ARB of AZ91 magnesium alloy at 350 ℃, 10-2 s-1 and reduction of 80%, the microstructure is refined in the earliest run and gradually uniformed during the subsequent ARB process. The mechanism of grain refinement is dynamic recrystallization mainly in the earliest stage of multi-run ARB process.