Effect of deformation temperature on mechanical properties of ultrafine grained Al–Mg alloys processed by rolling
Effect of deformation temperature on mechanical properties of ultrafine grained Al–Mg alloys processed by rolling
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DOI：
10.1016/j.matdes.2013.02.068
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发表时间：
2013-09
影响因子：
8.4
通讯作者：
Dharmendra Singh;P. N. Rao;R. Jayaganthan
中科院分区：
文献类型：
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作者：
Dharmendra Singh;P. N. Rao;R. Jayaganthan
对铝镁合金（Al 5083）进行了低温轧制（CR）和低温轧制后温轧（WR）处理，研究了其力学行为和微观组织的变化。首先将Al合金试样低温轧制至50%的厚度减少量，然后在100°C、145°C、175°C和200°C下温乳，直到实现总的90%的厚度减少量。通过透射电子显微镜（TEM）、电子背散射衍射（EBSD）和X射线衍射（XRD）技术分析比较了各条件下的最终组织，研究了WR变形温度对力学性能的影响。通过在室温下进行的硬度和拉伸测试来评价经处理的样品的机械行为。在175°C下，WR试样的屈服强度（522MPa）、极限抗拉强度（539MPa）和塑性（6.8%）均比CR试样有所提高，硬度也提高到146HV。将这些样品在150°C至300°C的温度范围内退火以研究其热稳定性。CR样品表现出严重的变形结构，具有高位错密度网络，而冷轧后温轧（WR）样品显示出与动态回复相关的超细晶粒的形成。在200°C的高温下，由于动态回复效应导致位错密度降低，WR样品的强度降低，伸长率增加。
Aluminum–Magnesium (Al 5083) alloy was subjected to cryorolling (CR) and cryorolling followed by warm rolling (WR) in order to investigate the changes in mechanical behavior and microstructure evolution in the present work. Al alloy specimens were first cryorolled up to 50% thickness reduction followed with warm rolling at 100°C, 145°C, 175°C and 200°C till to achieve total 90% thickness reduction. The final microstructure of all conditions were analyzed and compared through transmission electron microscopy (TEM), Electron back scattered diffraction (EBSD), and X-ray diffraction (XRD) techniques to investigate the effect of WR deformation temperatures on mechanical properties. The mechanical behavior of the processed samples were evaluated through hardness and tensile tests performed at room temperature. An increase in yield strength (522MPa), ultimate tensile strength (539MPa) and ductility (6.8%) was observed in WR specimens at 175°C, hardness also increases to (146HV) as compared to CR samples. These samples were annealed in temperature range from 150°C to 300°C to investigate their thermal stability. The CR samples exhibited severely deformed structure with high dislocation density network while cryorolled followed by warm rolled (WR) samples has shown formation of ultrafine grains associated with dynamic recovery. At elevated temperature of 200°C, WR samples showed decrease in strength accompanied with increase in elongation due to dominant dynamic recovery effect led to reduction in dislocation density.